CN119640783A - Prefabricated pile, combined pile and construction method - Google Patents
Prefabricated pile, combined pile and construction method Download PDFInfo
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- CN119640783A CN119640783A CN202411451302.0A CN202411451302A CN119640783A CN 119640783 A CN119640783 A CN 119640783A CN 202411451302 A CN202411451302 A CN 202411451302A CN 119640783 A CN119640783 A CN 119640783A
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Abstract
本发明提供一种预制桩、组合桩及施工方法，涉及桩基施工技术领域，预制桩包括：第一桩体，第一桩体沿长度方向的两端分别为第一端与第二端；多个第一加粗凸起，其固定于第一桩体的外周壁上且沿第一桩体的长度方向间隔设置；以及第一环形凸起，环绕固定于第一桩体上，至少一个第一加粗凸起位于第一环形凸起与第二端之间；预制桩置入钻孔中时，钻孔的内周壁沿第一桩体长度方向投影围绕于第一桩体与第一加粗凸起组合体沿第一桩体长度方向投影的外侧，第一环形凸起沿第一桩体长度方向投影完全覆盖钻孔的内周壁沿第一桩体长度方向投影。包含该预制桩的组合桩在完成施工后，其承载力可以得到提升。
The present invention provides a prefabricated pile, a combined pile and a construction method, which relates to the technical field of pile foundation construction. The prefabricated pile comprises: a first pile body, wherein the two ends of the first pile body along the length direction are respectively a first end and a second end; a plurality of first thickened protrusions, which are fixed on the outer peripheral wall of the first pile body and arranged at intervals along the length direction of the first pile body; and a first annular protrusion, which is fixed around the first pile body, and at least one first thickened protrusion is located between the first annular protrusion and the second end; when the prefabricated pile is placed in a borehole, the inner peripheral wall of the borehole is projected along the length direction of the first pile body around the outer side of the projection of the first pile body and the first thickened protrusion combination along the length direction of the first pile body, and the projection of the first annular protrusion along the length direction of the first pile body completely covers the projection of the inner peripheral wall of the borehole along the length direction of the first pile body. After the construction of the combined pile including the prefabricated pile is completed, its bearing capacity can be improved.
Description
Technical Field
The invention relates to the technical field of pile foundation construction, in particular to a precast pile, a combined pile and a construction method.
Background
Along with the improvement of urban building density, the pile foundation construction of increasingly new construction and reconstruction and expansion projects needs to reduce or even eliminate the soil compaction influence on the surrounding environment, so that the development of pile implantation technology is also driven. The pile implantation technology is early applied to coastal soft soil areas in China, the pile implantation construction technology needs to stir and liquefy soil in holes after drilling is completed, then piles are sent into soil, at the moment, the liquid level of medium in the holes rises and is partially discharged, and the soil squeezing effect is not generated, so that the pile implantation method is very suitable for soft soil foundations.
Under the existing construction process conditions of the implanted pile, two destructive interfaces exist on the pile body under the action of vertical load, namely an interface S1 of the core pile 7 and the pile periphery solidified soil 6 and an interface S2 of the pile periphery solidified soil 6 and undisturbed soil 5 around the hole wall, as shown in figure 1. According to the bearing capacity calculation formula, Q uk＝u∑ξsiqsikli+qpkAp, only the limit friction resistance of the two breaking interfaces S1 and S2 is improved, but the single pile bearing capacity of the implanted pile can be effectively improved.
In order to improve the bearing capacity of a single pile of an implanted pile, a bamboo joint pile is developed on the basis of a conventional pipe pile, and belongs to a special-shaped pipe pile, and the patent CN2611433Y is referred to, the pile body of the bamboo joint pile is provided with 'bamboo joints' protruding from the surface of the pile body at intervals, so that the bamboo joint pile is also called as a bamboo joint pile, unlike a pipe pile, the bamboo joint pile is difficult to cast in situ, although a literature indicates that the cast-in-place pile can be manufactured into a shape similar to the bamboo joint pile, no matter whether the drilling technology or the uncertainty of foundation construction conditions is caused, the size, the surface burrs and the bearing performance of the cast-in-place bamboo joint pile are obviously different from those of a prefabricated bamboo joint pile, the two are not miscible, the casting mode forms a special-shaped pile technology similar to the bamboo joint pile, the production and construction of the prefabricated bamboo joint pile is completely free from reference and reference meanings, and the industrial production test is not provided in practice. The prefabricated bamboo joint pile is very suitable for implantation construction, the traditional static pressure and hammering construction method is very outstanding in soil squeezing effect when being applied to the bamboo joint pile, and when the implantation construction method is used, the bamboo joint pile can be sent into a foundation in a non-soil squeezing mode because the drilling diameter is larger than that of the bamboo joint part. After the construction completed bamboo joint pile is combined with the pile periphery solidified soil 6, the pile periphery solidified soil 6 is not only contacted with the pile body, but also contacted with the bamboo joint surface, so that the peak shear stress of the interface S1 is effectively improved, and compared with a common precast pile with the same diameter, the interface S1 of the pile periphery solidified soil 6 and the core pile 7 is less prone to damage.
However, under the construction mode of the implantation method, the interface S2 between the solidified soil around the pile and the undisturbed soil around the hole wall is not improved compared with the common precast pile with the same diameter, and is currently used as a limiting factor of the single pile bearing capacity of the bamboo joint pile constructed by the implantation method. Although the bearing capacity can be improved by increasing the diameter of the pile body, the concrete consumption is inevitably and greatly increased along with the increase of the diameter of the pile body, the transportation and construction difficulties and the maintenance time of the bamboo joint pile are correspondingly increased, and the increased cost is not competitive in industrial application. Therefore, in order to further improve the bearing capacity of a single pile of an embedded pile without changing the diameter of the pile body or the diameter of a drilled hole, it is necessary to solve the problem of how to improve the limit friction between solidified soil around the pile and undisturbed soil around the hole wall.
Disclosure of Invention
The application aims to solve the technical problem of improving the limit friction between solidified soil around a pile and undisturbed soil around a hole wall, and provides a precast pile, a combined pile and a construction method.
In a first aspect, a precast pile includes:
the two ends of the first pile body along the length direction are a first end and a second end respectively;
a plurality of first thickening protrusions fixed on the outer peripheral wall of the first pile body and arranged at intervals along the length direction of the first pile body, and
The first annular bulge is circumferentially fixed on the first pile body, and at least one first thickening bulge is positioned between the first annular bulge and the second end;
when the precast pile is placed in the drilled hole, the projection of the inner peripheral wall of the drilled hole along the length direction of the first pile body surrounds the outer side of the projection of the first pile body and the first thickening protrusion combination body along the length direction of the first pile body, and the projection of the first annular protrusion along the length direction of the first pile body completely covers the projection of the inner peripheral wall of the drilled hole along the length direction of the first pile body.
Compared with the prior art, the precast pile has the advantages that when the precast pile is implanted into a drilled hole, a closed cavity is formed by the lower end face of the first annular bulge, the peripheral wall of the first pile body and the side wall of the drilled hole, cement soil at the lower side of the first annular bulge in the drilled hole is extruded, so that the pressure intensity of the lower side of the lower end face of the first annular bulge in the drilled hole is increased, the cement soil enters a soil body gap around the hole wall, the bonding strength between solidified soil around the pile and undisturbed soil around the hole wall is improved, the limit friction resistance of an interface S2 between the solidified soil around the pile and undisturbed soil around the hole wall is increased, and the single pile bearing capacity of the precast pile after implantation is improved. In addition, the cement soil around the first thickening protrusion is extruded by the first annular protrusion, the density is increased, acting force between the first thickening protrusion and the surrounding cement soil is increased, and further the limit friction of an interface S1 between the precast pile and the solidified soil around the pile is improved, and the single pile bearing capacity of the precast pile after the precast pile is implanted is further improved.
In a preferred embodiment, the precast pile further comprises at least one second annular protrusion circumferentially fixed on the outer peripheral wall of the first pile body, the second annular protrusion being located between the first annular protrusion and the second end, the first annular protrusion overlapping the second annular protrusion along the first pile body longitudinal direction projection and the outer peripheral wall of the second annular protrusion being located outside the borehole along the first pile body longitudinal direction projection, or the outer peripheral wall of the first annular protrusion being at least partially coincident with the outer peripheral wall of the second annular protrusion along the first pile body longitudinal direction projection.
In a preferred embodiment, the second annular protrusion is provided with at least one pressure relief channel, and the pressure relief channel penetrates through the second annular protrusion along the length direction of the first pile body;
And/or at least one first thickening protrusion is arranged between the first annular protrusion and the second annular protrusion.
In a preferred embodiment, the second annular protrusion is provided with more than two pressure relief channels distributed at intervals along the circumferential direction, and/or at least one pressure relief channel is a through hole or a notch.
In a preferred embodiment, the first pile body, the first thickening protrusion, the first annular protrusion and the second annular protrusion are integrally preformed;
The first pile body is hollow circular pile setting, and is a plurality of first thickening protruding edge the length direction of first pile body is the bamboo joint form setting, first annular protruding with the second annular is protruding all to be the ring form setting, first thickening protruding first annular protruding the second annular protruding with first pile body is coaxial setting.
In a preferred embodiment, the first pile body, the first thickening protrusion, the first annular protrusion and the second annular protrusion are integrally preformed;
The first pile body is hollow square pile setting, first thickening protruding first annular protruding with the annular protruding second is square annular setting, first thickening protruding first annular protruding with the annular protruding second all parallel around in the outside of first pile body.
In a preferred embodiment, the first pile body and the first thickening protrusions are integrally preformed, the first pile body is arranged in a hollow round pile, and a plurality of first thickening protrusions are arranged in a bamboo joint shape along the length direction of the first pile body;
The first annular bulge and the second annular bulge are all annular, the first thickening bulge, the first annular bulge, the second annular bulge and the first pile body are coaxially arranged, the first annular bulge and/or the second annular bulge comprises more than two arc-shaped bulges which can be mutually spliced to form an annular shape, and the arc-shaped bulges are welded and fixed or detachably fixed on the first pile body.
In a preferred embodiment, a groove is formed in the inner peripheral wall of the arc-shaped protrusion, and when the arc-shaped protrusion is fixed on the first thickening protrusion, the outer peripheral wall of the first thickening protrusion and the inner side wall of the groove are mutually attached to limit the arc-shaped protrusion axially.
In a preferred embodiment, the arc-shaped protrusion is prefabricated by concrete, a first embedded steel part extending along the circumferential direction is embedded in at least one of two ends of the arc-shaped protrusion in the length direction of the first pile body, a second embedded steel part extending along the circumferential direction and corresponding to the first embedded part is embedded in the first pile body, and the first embedded steel part is welded on the second embedded steel part correspondingly.
In a preferred embodiment, a plurality of first steel bars, first connecting bars and radial bars are embedded in the arc-shaped bulge, the first steel bars are uniformly distributed along the circumferential direction of the arc-shaped bulge, the first steel bars extend along the axial direction of the arc-shaped bulge, one ends of the two first connecting bars are respectively connected with two ends of the first steel bars, the other ends of the two first connecting bars are respectively welded and fixed with two first embedded steel pieces, the radial bars are connected to the first steel bars and uniformly distributed along the length direction of the first steel bars, and the radial bars extend along the radial direction of the arc-shaped bulge;
The first pile body is embedded with a plurality of second reinforcing bars and second connecting bars, a plurality of second reinforcing bars are evenly distributed along the circumference of the first pile body and are fixed on the prestress main bar of the first pile body, the second reinforcing bars correspond to the first thickening protrusion, two one ends of the second connecting bars are respectively connected to two ends of the second reinforcing bars, and the other ends of the second connecting bars are respectively welded and fixed with two second embedded steel pieces on two axial sides of the first thickening protrusion.
In a preferred embodiment, the arc-shaped protrusion is prefabricated by concrete, a through hole extending along the radial direction is formed in the arc-shaped protrusion, the through hole penetrates through the inner peripheral wall and the outer peripheral wall of the arc-shaped protrusion, a bolt hole is formed in the outer peripheral wall of the first thickening protrusion, and an expansion bolt penetrating through the through hole is assembled in the bolt hole so as to fix the arc-shaped protrusion to the first thickening protrusion.
In a preferred embodiment, the first annular protrusion and/or the second annular protrusion comprises a first conical surface, a cylindrical surface and a second conical surface which are sequentially connected from the first end to the second end of the first pile body, the cylindrical surface extends along the length direction of the first pile body and surrounds the outer side of the first pile body, the first conical surface faces towards the end part of the first end to be connected with the first pile body, the second conical surface faces towards the end part of the first end to be connected with the first pile body, and the second conical surface is matched with the first pile body to form an annular concave cavity with an opening towards the second end.
In a preferred embodiment, the first annular protrusion and/or the second annular protrusion each include a first conical surface, a cylindrical surface and a second conical surface which are sequentially connected from the first end to the second end of the first pile body, the cylindrical surface extends along the length direction of the first pile body and surrounds the outer side of the first pile body, the end of the first conical surface facing the first end and the end of the second conical surface facing the second end are both connected with the first pile body, the diameter of the first conical surface gradually increases from the first end to the second end of the first pile body, and the diameter of the second conical surface gradually decreases from the first end to the second end of the first pile body.
In a preferred embodiment, the angle between the second conical surface and the length direction of the first pile body is greater than 45 degrees and less than 90 degrees.
In a preferred embodiment, the first pile body and the first thickening protrusion are integrally preformed;
the outer peripheral wall of the end plate of the first end is projected around the outer side of the first thickening protrusion projected along the length direction of the first pile body, and the part of the end plate of the first end, extending out of the first pile body, forms the first annular protrusion.
In a preferred embodiment, the first pile body and the first thickening protrusion are integrally preformed;
the first annular bulge is arranged in an end plate shape, a plurality of penetrating holes which are distributed at intervals are formed in the first annular bulge, the penetrating holes penetrate through two end faces of the first annular bulge in the length direction of the first pile body, threaded holes corresponding to the penetrating holes are formed in the end plate at the first end of the first pile body, and bolts penetrating through the penetrating holes are assembled in the threaded holes so that the first annular bulge is fixed on the first pile body.
In a preferred embodiment, the threaded bore is an anchor bore of an end plate of the first pile body first end for passage of an upset head from the first end to the second end.
In a preferred embodiment, the length of the first pile body is defined as L, the first end is a starting point, and the first annular protrusion is located within an interval of [0, L/2] of the first pile body.
In a preferred embodiment, the first annular projection is located within the [0, L/4] interval of the first pile body.
In a preferred embodiment, the first thickening protrusion and the first annular protrusion are both parallel and surround the outer side of the first pile body, and the distance from the outer edge of the first thickening protrusion projected along the length direction of the first pile body to the outer edge of the first annular protrusion projected along the length direction of the first pile body is a fixed value, and the fixed value is not less than 40mm and not more than 150mm.
In a preferred embodiment, the first pile body is a hollow circular pile, the first thickening protrusion and the first annular protrusion are all circular ring-shaped, the first thickening protrusion and the first annular protrusion are coaxially arranged, the outer diameter of the first annular protrusion is 0 to 50mm larger than the diameter of the drilled hole, and the outer diameter of the first thickening protrusion is 40 to 100mm smaller than the diameter of the drilled hole.
In a preferred embodiment, the first pile body is a hollow round pile, the first thickening protrusions and the first annular protrusions are all in annular arrangement, the first thickening protrusions and the first pile body are coaxially arranged, the outer diameter of the first pile body is 350mm to 750mm, the outer diameter of the first annular protrusions is 90mm to 200mm larger than that of the first pile body, the outer diameter of the first thickening protrusions is 50mm to 150mm larger than that of the first pile body, and the outer diameter of the first annular protrusions is 40mm to 150mm larger than that of the first thickening protrusions.
In a second aspect, the present application provides a composite pile comprising:
A top precast pile composed of the precast piles as described above, and
At least one bottom precast pile connected to the lower end of the top precast pile;
The bottom precast pile comprises a second pile body extending vertically, and the projection of the peripheral wall of the second pile body along the length direction of the first pile body is completely overlapped with the projection of the peripheral wall of the first pile body along the length direction of the first pile body.
Compared with the prior art, the combined pile has the advantages that when the top precast pile is implanted into a drilled hole, a closed cavity is formed by the lower end face of the first annular bulge, the peripheral wall of the first pile body and the side wall of the drilled hole, cement soil at the lower side of the first annular bulge in the drilled hole is extruded, so that the pressure intensity of the lower side of the lower end face of the first annular bulge in the drilled hole is increased, the cement soil enters a soil body gap around the hole wall, the bonding strength between the solidified soil around the pile and the undisturbed soil around the hole wall is improved, the limit friction resistance of an interface S2 between the solidified soil around the pile and the undisturbed soil around the hole wall is increased, and the single pile bearing capacity of the combined pile after implantation is improved. In addition, the cement soil on the lower side of the first annular bulge is extruded by the first annular bulge, the density is increased, the acting force between the first thickening bulge, the concrete pile and surrounding cement soil is increased, the limit friction resistance of an interface S1 between the combined pile and the solidified soil around the pile is further improved, and the single pile bearing capacity of the combined pile after the combined pile is implanted is further improved.
In a preferred embodiment, the bottom precast pile further comprises a plurality of second thickening protrusions circumferentially fixed on the outer peripheral wall of the second pile body, the second thickening protrusions and the second pile body are integrally precast and formed, the plurality of second thickening protrusions are arranged at intervals along the length direction of the second pile body, and the outer peripheral wall of the first annular protrusion is projected around the outer side of the projection of the second pile body and the second annular protrusion assembly along the length direction of the first pile body.
In a preferred embodiment, the second pile body and the first pile body are all hollow round piles, the first thickening protrusions, the first annular protrusions and the second thickening protrusions are all round annular, the first thickening protrusions, the first annular protrusions, the second thickening protrusions, the second pile body and the first pile body are coaxially arranged, a plurality of second thickening protrusions are arranged along the length direction of the second pile body in a bamboo joint shape, and the outer diameter of the second annular protrusions is equal to that of the first thickening protrusions.
In a preferred embodiment, the bottom precast piles are tubular structures having an inner cavity, and a blocking structure for at least partially blocking the inner cavity is fixed to at least one of the bottom precast piles, or at least one of the bottom precast piles is a solid structure.
In a preferred embodiment, the blocking structure is an end closure plate provided at the end of the bottom precast pile.
In a preferred embodiment, the pile further comprises a constant-section pipe pile connected to the upper end of the precast pile, the constant-section pipe pile extends vertically and is integrally precast by concrete, and the projection of the outer peripheral wall of the constant-section pipe pile along the length direction of the first pile body coincides with the projection of the outer peripheral wall of the first annular protrusion along the length direction of the first pile body.
In a preferred embodiment, the first annular protrusion is disposed at the uppermost end of the first pile body and is connected with the constant-section pipe pile, the first annular protrusion and the first pile body are integrally preformed, the upper end face, the outer peripheral face and the lower end face of the first annular protrusion are sequentially connected from top to bottom, the upper end face of the first annular protrusion extends from the outer peripheral face to the first pile body, the upper end face of the first annular protrusion and the upper end face of the first pile body are coplanar, the outer peripheral face of the first annular protrusion extends vertically and surrounds the outer side of the first pile body, the lower end face of the first annular protrusion extends from the outer peripheral face to the first pile body, the lower end face of the first annular protrusion is in a conical surface, and the diameter of the lower end face of the first annular protrusion gradually decreases from top to bottom.
In a third aspect, the present application provides a precast pile construction method, using a precast pile as described above or a composite pile as described above.
In a fourth aspect, the present application provides a construction method using the composite pile as described above, comprising the steps of:
S1, drilling, namely designing the size of a drilling hole according to the cross section size of a first pile body of a precast pile, wherein the orthographic projection of the inner peripheral wall of the drilling hole on a horizontal plane surrounds the outer side of the orthographic projection of the first pile body and the first thickening protrusion combination body on the horizontal plane, and the orthographic projection of the inner peripheral wall of the drilling hole on the horizontal plane is completely covered by the orthographic projection of a second annular protrusion on the horizontal plane;
s2, drilling construction, namely drilling according to drilling settings;
S3, planting piles and grouting the bottom precast piles, wherein at least one bottom precast pile is placed into a drilled hole, and solidification slurry injection is carried out in the drilled hole;
And S4, planting the top precast pile, namely placing the precast pile at the upper end of the bottom precast pile at the uppermost end, and pressing the precast pile into the drilled hole, wherein the first annular bulge and the second annular bulge squeeze soil mass and/or solidified slurry on the surrounding wall of the drilled hole in the process of placing the precast pile into the drilled hole.
Compared with the prior art, the construction method of the combined pile has the advantages that the precast pile is adopted as the top precast pile of the combined pile, when the precast pile is implanted into a drilled hole, a closed cavity is formed by the lower end face of the first annular bulge, the peripheral wall of the first pile body and the side wall of the drilled hole, cement soil at the lower side of the first annular bulge in the drilled hole is extruded, so that the pressure intensity of the lower side of the lower end face of the first annular bulge in the drilled hole is increased, the cement soil enters a soil body gap around the hole wall, the bonding strength between the solidified soil around the pile and the undisturbed soil around the hole wall is improved, the limit friction resistance of an interface S2 between the solidified soil around the pile and the undisturbed soil around the hole wall is increased, and the single pile bearing capacity of the combined pile after implantation is improved. In addition, the cement soil on the lower side of the first annular bulge is extruded by the first annular bulge, the density is increased, the acting force between the first thickening bulge, the precast pile and surrounding cement soil is increased, the limit friction resistance of an interface S1 between the combined pile and the solidified soil around the pile is further improved, and the single pile bearing capacity of the combined pile after implantation is further improved.
In a preferred embodiment, the grouting is performed by injecting a volume of the cured slurry into the borehole, such that the surface of the cured slurry is pressed into contact with the second annular projection or the first annular projection before the precast pile is fully pressed into the borehole.
In a preferred embodiment, the length of the bottom 2.6m of the section of the bottom precast pile which is first inserted into the borehole has at least four second thickening protrusions distributed.
In a preferred embodiment, step S2 further comprises performing an expanded diameter drilling at the bottom of the borehole, the borehole cavity portion of the expanded diameter drilling accommodating at least four second thickening protrusions of the bottom of the section of the bottom precast pile first inserted into the borehole.
In a preferred embodiment, the depth of the expanded bore is greater than 2m and less than 3m, preferably greater than 2.4m and less than 2.8m.
Drawings
FIG. 1 is a diagram of analysis of the load bearing capacity of prior art implantation;
Fig. 2 is a schematic structural view of a precast pile according to embodiment 1 of the present application;
fig. 3 is a schematic view showing the projection of the drilled hole, the first annular protrusion, the second annular protrusion and the first thickened protrusion along the length direction of the first pile body according to embodiment 1 of the present application;
FIG. 4 is a graph showing the Q-S curves of the precast pile and the pipe pile and the bamboo joint pile according to the embodiment 1 of the present application;
FIG. 5 is a schematic diagram of a preformed pile welded on a first pile body by a first annular protrusion according to embodiment 1 of the present application;
FIG. 6 is a partial schematic view of the connection of the first annular protrusion of FIG. 5 with the first pile body and the first thickening protrusion;
FIG. 7 is a schematic diagram showing a precast pile with a first annular protrusion detachably fixed to a first pile body according to embodiment 1 of the present application in full section;
fig. 8 is a schematic structural view of the first annular protrusion of embodiment 1 of the present application integrally preformed on the upper end of the first pile body;
fig. 9 is a schematic structural view of the first annular protrusion of embodiment 1 of the present application detachably fixed to the upper end of the first pile body;
FIG. 10 is an exploded view showing the first annular protrusion of embodiment 1 of the present application detachably fixed to the upper end of the first pile body;
Fig. 11 is an enlarged view of a portion a in fig. 10;
FIG. 12 is a schematic view of a precast pile with a pressure relief channel on a first annular protrusion according to embodiment 1 of the present application;
fig. 13 is a schematic structural view of a precast pile according to embodiment 1 of the present application;
fig. 14 is a schematic structural diagram of a composite pile according to embodiment 2 of the present application;
Fig. 15 is a schematic view of a structure of a composite pile according to embodiment 2 of the present application in which pressure is regulated by an end seal plate;
fig. 16 is a schematic diagram of a combined pile according to embodiment 2 of the present application;
FIG. 17 is a first flow chart of construction of a composite pile according to embodiment 3 of the present application;
FIG. 18 is a second flow chart of construction of the composite pile according to embodiment 3 of the present application;
fig. 19 is a schematic view showing the bottom precast pile first inserted into the borehole in fig. 18 being inserted into the bottom of the enlarged borehole.
Reference numerals illustrate:
1. Precast pile 10, first pile body, first thickened protrusion 111, concave groove 112, bolt hole 12, first annular protrusion 120, arc protrusion 121, first pre-embedded steel piece 122, first conical surface 123, cylindrical surface 124, second conical surface 122', first conical surface 123', cylindrical surface 124', second conical surface 21, second thickened protrusion 125, groove 126, first reinforced bar 127, first connecting rib 128, radial rib 129, through hole 129', penetrating hole 13, second annular protrusion 131, pressure relief channel 14, second pre-embedded steel piece 15, prestress main rib 151, hoop sleeve 16, second reinforced bar 161, second connecting rib 17, expansion bolt 18, bolt 19, threaded hole 191, through rib hole 192, large diameter hole 193, small diameter hole 2, bottom precast pile 20, second pile body 21, second thickened protrusion 3, end sealing plate 30, pressure regulating hole 4, constant section pipe pile hole wall 5, 6, circumferential solidification pile 7, circumferential soil.
Detailed Description
First, it should be understood by those skilled in the art that these embodiments are merely for explaining the technical principles of the embodiments of the present application, and are not intended to limit the protection scope of the embodiments of the present application. Those skilled in the art can adapt it as desired to suit a particular application.
In describing embodiments of the present application, it should be noted that, unless explicitly stated or limited otherwise, the terms "connected," "connected," and "coupled" should be construed broadly, and may be, for example, fixedly connected, detachably connected, integrally connected, mechanically connected, electrically connected, directly connected, or indirectly connected via an intermediate medium. The specific meaning of the above terms in embodiments of the present application will be understood in detail by those of ordinary skill in the art.
In embodiments of the application, unless expressly specified and limited otherwise, a first feature "up" or "down" on a second feature may be that the first and second features are in direct contact, or that the first and second features are in indirect contact via an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.
The present application will be described in further detail with reference to fig. 2 to 18 and the specific examples.
Example 1
Referring to fig. 2-13, the embodiment of the application discloses a precast pile.
Referring to fig. 2, the precast pile of the present embodiment includes a first pile body 10, a plurality of first thickening protrusions 11, and first annular protrusions 12. The first pile body 10 is integrally prefabricated by concrete, and the first pile body 10 may be a pipe pile or a solid pile, and in this embodiment, the first pile body 10 is described by taking the pipe pile as an example. The two ends of the first pile body 10 along the length direction are a first end 10 'and a second end 10", a plurality of first thickening protrusions 11 are located between the first end 10' and the second end 10", the first thickening protrusions 11 are fixed on the peripheral wall of the first pile body 10 and are arranged at intervals along the length direction of the first pile body 10, the first thickening protrusions 11 can be annular with closed circumference continuously or formed by a plurality of block protrusions distributed at intervals along the circumference, and the first thickening protrusions 11 and the first pile body 10 are combined to form special-shaped piles with alternating thicknesses along the length direction, such as bamboo joint piles, special-shaped square piles with alternating thicknesses along the length direction, and the like. In this embodiment, the first pile body 10 is described by taking a vertical extension as an example, that is, the first pile body 10 is vertically disposed along the length direction, the first end 10' is the uppermost end of the first pile body 10, and the second end 10″ is the lowermost end of the first pile body 10.
According to the construction of the implantation method, before the precast pile 1 is implanted into the foundation, the foundation structure of the core pile, the pile periphery solidified soil, the hole wall periphery undisturbed soil is finally realized through the procedures of drilling, bottom expanding, stirring and grouting. The interface S1 between the core pile and the solidified soil around the pile is increased in contact surface and more in stress direction due to the action of the first thickening protrusion 11, and the interfacial peak shear stress is improved, however, in consideration of market competition, the interface S2 between the solidified soil around the pile and the undisturbed soil around the hole wall is not improved compared with the common precast pile with the same diameter under the condition that the diameter of the first pile body 10 or the hole diameter is not changed during implantation, and is a key factor for limiting the bearing capacity of the special-shaped pile single pile with alternate thickness along the length direction of the implantation construction. Therefore, in order to further increase the single pile bearing capacity of the implanted pile, it is necessary to solve the problem of how to increase the limit friction of the interface S2 between the solidified soil around the pile and the undisturbed soil around the hole wall.
In this embodiment, the first annular protrusion 12 is circumferentially fixed on the first pile body 10, and the at least one first thickening protrusion 11 is located between the first annular protrusion 12 and the second end 10", i.e. the first annular protrusion 12 is located above the at least one first thickening protrusion 11. In order to improve the limit friction of the interface S2 between the solidified soil around the pile and the undisturbed soil around the hole wall, the outer peripheral wall of the first annular protrusion 12 is projected around the outer side of the first thickening protrusion 11 projected along the length direction of the first pile body 10.
According to the construction of the implantation method, when the precast pile 1 is implanted into a drilled hole, as the outer peripheral wall of the first annular bulge 12 is projected and encircled on the outer side of the first thickening bulge 11 projected along the length direction of the first pile body 10, in the downward implantation process, the lower end face of the first annular bulge 12 extrudes the cement soil positioned on the lower side of the first annular bulge 12 in the drilled hole, the cement soil is enabled to diffuse towards the soil around the drilled hole by increasing the compression strength, and part of the cement soil enters into soil gaps around the hole wall, so that the bonding strength between the solidified soil around the pile and the undisturbed soil around the hole wall is improved, the limit friction force of an interface S2 between the solidified soil around the pile and the undisturbed soil around the hole wall is improved, and the single pile bearing capacity after the precast pile 1 is implanted is further improved.
The first annular bulge 12 is arranged above the first thickening bulge 11, the outer peripheral wall of the first annular bulge 12 is projected and encircling the first thickening bulge 11 along the length direction of the first pile body 10, and the outer side of the first thickening bulge 11 along the length direction of the first pile body 10 is projected, so that cement soil around the first thickening bulge 11 is extruded by the first annular bulge 12 in the downward implantation process, the density is increased, the acting force between the first thickening bulge 11 and surrounding cement soil is increased, the limit friction of an interface S1 between the precast pile 1 and the solidified soil around the pile is further improved, and the single pile bearing capacity of the precast pile 1 after implantation is further improved.
During the downward implantation, the extrusion effect of the lower end surface of the first annular protrusion 12 against the soil cement located at the lower side of the first annular protrusion 12 in the borehole is affected by the physical characteristics of the first annular protrusion 12. To enhance the extrusion effect of the lower end surface of the first annular protrusion 12 on the lower cemented soil during construction, it is preferable that, in some examples, the first annular protrusion 12 is projected in the longitudinal direction of the first pile body 10 to completely cover the inner peripheral wall of the drilled hole and is projected in the longitudinal direction of the first pile body 10.
Preferably, the first annular projections 12 are located above all the first thickening projections 11 or the first annular projections 12 are located at the same height as the uppermost first thickening projections 11, most of the first thickening projections 11 being located below the first annular projections 12. During construction, the lower end face of the first annular bulge 12 can effectively extrude cement soil in a drill hole at the lower side of the first annular bulge, but cannot extrude cement soil at the upper side of the first annular bulge, so that most of the first thickening bulge 11 is positioned at the lower side of the first annular bulge 12, most of cement soil around the first thickening bulge 11 can be extruded, and the integral bearing capacity of the precast pile 1 after implantation is improved.
According to the construction of the implantation method, when the precast pile 1 is implanted into the drilled hole, the projection of the inner peripheral wall of the drilled hole along the length direction of the first pile body 10 surrounds the outer side of the projection of the combination of the first pile body 10 and the first thickening protrusion 11 along the length direction of the first pile body 10, and the implantation action can be completed by depending on the self weight of the precast pile 1 and the pile-holding pressing down of the pile-planting machine. In these examples, the projection of the first annular projection 12 along the length of the first pile body 10 completely covers the projection of the inner circumferential wall of the borehole along the length of the first pile body 10, meaning that additional pressure is required by the pile driver when the first annular projection 12 is to be implanted into the borehole.
In these examples, when the precast pile 1 is implanted into a borehole, particularly when the first annular protrusion 12 enters the borehole, the lower end surface of the first annular protrusion 12 forms a closed cavity with the outer peripheral wall of the first pile body 10 and the side wall of the borehole.
In these examples, as the precast pile 1 descends, the first annular protrusion 12 gradually increases the pressure in the closed cavity, and drives the cement soil to diffuse to the soil around the hole wall. Due to the closed cavity, the extrusion effect is remarkable, and cement soil can more effectively enter into soil gaps around the hole wall, so that the bonding strength between the solidified soil around the pile and the undisturbed soil around the hole wall is improved, the limit friction resistance of an interface S2 between the solidified soil around the pile and the undisturbed soil around the hole wall is increased, and the single pile bearing capacity of the precast pile 1 after being implanted is improved. In this example, since the first annular protrusion 12 is projected along the length direction of the first pile body 10 to completely cover the inner circumferential wall of the borehole, and is projected along the length direction of the first pile body 10, when the first annular protrusion 12 enters the borehole, the formed closed cavity can remarkably enhance the extrusion effect of the lower end surface of the first annular protrusion 12 on the lower cement soil, the cement soil can actively diffuse to the soil around the borehole wall by virtue of soil gaps, and the limit friction of the interface S2 between the solidified soil around the pile and the undisturbed soil around the borehole wall is obviously enhanced.
Preferably, with the first pile body 10 being a hollow circular pile, the plurality of first thickening protrusions 11 are bamboo-shaped along the length direction of the first pile body 10, the first annular protrusions 12 are circular, the first pile body 10, the first thickening protrusions 11 and the first annular protrusions 12 are coaxial, for example, in order to make the first annular protrusions 12 completely cover the inner peripheral wall of the drilled hole along the length direction projection of the first pile body 10, and the outer diameter of the first annular protrusions 12 is set to be 0 to 50mm larger than the diameter of the drilled hole. According to the experimental data of the early test pile, once the outer diameter of the first annular bulge 12 exceeds the bore diameter by more than 50mm, the extra static pressure load required to be applied during construction is overlarge, the construction difficulty is greatly improved, meanwhile, in the maintenance period after the test pile construction is completed, according to the monitoring of surrounding soil, the soil squeezing effect brought by the test pile is obvious, and the test pile is especially unsuitable for soft soil foundations. In addition, based on a single pile load test of the engineering stiffness composite pile, a three-dimensional model is built by adopting FLAC3D finite difference software, the outer diameter of a pile body of a reference test pile is 450mm, the outer diameter of a first thickened bulge 11 is 500mm, the outer diameter of a first annular bulge 12 is 550mm, the outer diameter of a bamboo joint pile body is 450mm, the outer diameter of a bamboo joint part is 500mm, and the outer diameter of a pipe pile is 500mm, the ultimate bearing capacity of the single pile after the construction is implanted, the pile length is calculated to be 40m, a gravel sand layer is used as a pile end bearing layer, the bore hole diameter is 550mm, pile end bottom expansion is not carried out, a single pile bearing capacity comparison graph of the test pile, the bamboo joint pile and the pipe pile is obtained, as shown in fig. 4, by combining with table 1, the single pile concrete consumption of the test pile is increased by not more than 2.4% compared with a conventional 450mm/500mm bamboo joint pile, the single pile bearing capacity is increased by 28.57% compared with a conventional 450mm/500mm bamboo joint pile, and the pile circumference ground does not produce a soil squeezing phenomenon after a maintenance period. And the construction difficulty, the implantation effect, the raw material cost and other factors are integrated, so that the pile has a competitive advantage compared with bamboo piles of the same size or larger size in the market.
Table 1450mm/500mm/550mm test pile vs. 450mm/500mm bamboo joint pile
| Pile type | Pile body size | Bamboo joint size | Single pile concrete dosage | Bearing capacity of single pile | Soil squeezing effect |
| Test pile | 450mm | 500mm/550mm | 4.70 | 4500kN | Soil squeezing-free |
| Bamboo joint pile | 450mm | 500mm | 4.59 | 3500kN | Soil squeezing-free |
In addition to the above-described test piles, alternatively, the outer diameter of the first pile body 10 is 350mm to 750mm, the outer diameter of the first annular projection 12 is 90mm to 200mm larger than the outer diameter of the first pile body 10, the outer diameter of the first thickening projection 11 is 50mm to 150mm larger than the outer diameter of the first pile body 10, and the outer diameter of the first annular projection 12 is 40mm to 150mm larger than the outer diameter of the first thickening projection 11.
Referring to fig. 2, in some examples, defining the length of the first pile body 10 as L, the first end 10' as a starting point, the first annular protrusion 12 is located within the [0, L/2] interval of the first pile body 10, and further, the first annular protrusion 12 is located within the [0, L/4] interval of the first pile body 10. The upper portion of first pile body 10 is located to first annular arch 12, and the upper end of precast pile 1 is connected inseparabler through the soil body around first annular arch 12 and the pore wall, and first annular arch 12 is bigger for cement soil structural strength moreover, can bear bigger horizontal load to improve precast pile 1 horizontal bearing capacity after implantation. In addition, the upper portion of first pile body 10 is located to protruding 12 of first annular, is located the protruding 12 downside of first annular and can be in the more cement soil of the protruding 12 of vertical support first annular for precast pile 1 is difficult for subsidence after implanting, thereby improves precast pile 1 and implants the vertical bearing capacity after.
Further, with continued reference to fig. 2, the preformed pile 1 further comprises at least one second annular protrusion 13 circumferentially fixed to the peripheral wall of the first pile body 10, the second annular protrusion 13 being located between the first annular protrusion 12 and the second end 10 ". The number of the second annular protrusions 13 may be one or two or more, and when the number of the second annular protrusions 13 is two or more, the two or more second annular protrusions 13 are arranged at intervals along the length direction of the first pile body 10.
Referring to fig. 2 and 3, the projection of the first annular protrusion 12 along the length direction of the first pile body 10 covers the projection of the second annular protrusion 13 along the length direction of the first pile body 10, or the projection of the outer peripheral wall of the first annular protrusion 12 along the length direction of the first pile body 10 at least partially overlaps the projection of the outer peripheral wall of the second annular protrusion 13 along the length direction of the first pile body 10. The outer peripheral wall of the first pile body 10 is projected to be S3 along the length direction of the first pile body 10, the outer peripheral wall of the first thickening protrusion 11 is projected to be S4 along the length direction of the first pile body 10, the first thickening protrusion 11 is projected to be an annular space between S3 and S4 along the length direction of the first pile body 10, the inner peripheral wall of the drilled hole is projected to be S5 along the length direction of the first pile body 10, the drilled hole is projected to be a space in S5 along the length direction of the first pile body 10, the outer peripheral wall of the second annular protrusion 12 is projected to be S6 along the length direction of the first pile body 10, the outer peripheral wall of the second annular protrusion 12 is projected to be an annular space between S6 and S3 along the length direction of the first pile body 10, and the first annular protrusion 12 is projected to be an annular space between S7 and S3 along the length direction of the first pile body 10. When the first annular bulge 12 is projected along the length direction of the first pile body 10 to cover the second annular bulge 13 and projected along the length direction of the first pile body 10, the contact surface of the interface S1 between the precast pile 1 and the solidified soil around the pile is increased due to the effect of the second annular bulge 13, the stress direction is increased, the peak shear stress of the interface is improved, meanwhile, the cement soil at the lower side of the first annular bulge 12 in the drilled hole is extruded by the first annular bulge 12, the density is increased, the acting force between the second annular bulge 13 and surrounding cement soil is increased, the limit friction of the interface S1 between the precast pile 1 and the solidified soil around the pile is further improved, and the single pile bearing capacity of the precast pile 1 after being implanted is further improved.
When the projection of the outer peripheral wall of the first annular bulge 12 along the length direction of the first pile body 10 is completely overlapped with the projection of the outer peripheral wall of the second annular bulge 13 along the length direction of the first pile body 10, and the first annular bulge 12 and the second annular bulge 13 are solid annular, or the projection of the first annular bulge 12 along the length direction of the first pile body 10 covers the projection of the second annular bulge 13 along the length direction of the first pile body 10, and the projection of the outer peripheral wall of the second annular bulge 13 along the length direction of the first pile body 10 is positioned outside the projection of the first pile body 10 along the length direction of the drilled hole, the cement soil in the drilled hole can be separated into a closed cavity by the first annular bulge 12, the second annular bulge 13, the outer peripheral wall of the first pile body 10 and the side wall of the drilled hole. Along with the implantation of precast pile 1, the cement soil of second annular protruding 13 downside overflows to this second annular protruding 13 upside' S airtight cavity, owing to be airtight cavity, along with the increase of cement soil in the airtight cavity, the pressure constantly increases in the airtight cavity, consequently the extrusion effect to intracavity cement soil is showing in the work progress, cement soil can get into the peripheral soil body space of pore wall more effectively, with this joint strength between the peripheral solidified soil of improvement stake and the undisturbed soil of pore wall, the limit frictional resistance of interface S2 between the peripheral solidified soil of increase stake and the undisturbed soil of pore wall improves the single pile bearing capacity after precast pile 1 implants.
Further, at least one first thickening protrusion 11 is arranged between the first annular protrusion 12 and the second annular protrusion 13, so that the pressurizing and compacting effects of the first annular protrusion 12 on the cement soil in the closed cavity are fully utilized. The acting force of the extruded cement soil in the closed cavity and the first thickening protrusion 11 positioned in the closed cavity is increased, the limit friction resistance of the interface S1 between the pile body of the part of the precast pile 1 and the solidified soil around the pile is increased, and the single pile bearing capacity of the precast pile 1 after being implanted is further improved.
In addition, because the drilling holes in the construction of the implantation method are different from the conventional hole guiding, the pile body can be inclined in the implantation process after grouting is finished due to the environmental factors of actual construction. When the precast pile 1 is implanted into a drilled hole, as the first annular protrusion 12 completely covers the inner peripheral wall of the drilled hole along the length direction projection of the first pile body 10, and the outer peripheral wall of the first annular protrusion 12 at least partially coincides with the second annular protrusion 13 along the length direction projection of the first pile body 10, or the first annular protrusion 12 covers the second annular protrusion 13 along the length direction projection of the first pile body 10 and the outer peripheral wall of the second annular protrusion 13 is positioned at the outer side of the first pile body 10 along the length direction projection of the first pile body 10, the coaxiality of the precast pile 1 and the drilled hole can be improved, and the technical problem that the precast pile 1 is implanted and biased due to a construction environment by adopting an implantation method is solved.
With continued reference to fig. 2, optionally, in some examples, the first pile body 10 is a hollow circular pile, the plurality of first thickened protrusions 11 are bamboo-shaped along the length direction of the first pile body 10, the first annular protrusions 12 and the second annular protrusions 13 are all circular-shaped, the outer diameters of the first annular protrusions 12 and the second annular protrusions 13 are equal, and the first thickened protrusions 11, the first annular protrusions 12, the second annular protrusions 13 and the first pile body 10 are coaxially arranged.
The first pile body 10, the first thickening protrusion 11, the first annular protrusion 12 and the second annular protrusion 13 are integrally prefabricated and centrifugally formed by utilizing a steel die, so that the pile body is produced without later assembly, and the production flow is simple to operate. The first annular bulge 12, the second annular bulge 13 and the first pile body 10 are integrally preformed, the first annular bulge 12 and/or the second annular bulge 13 respectively comprise a first conical surface 122, a cylindrical surface 123 and a second conical surface 124 which are sequentially connected from top to bottom, wherein the upper end of the first conical surface 122 and the lower end of the second conical surface 124 are respectively connected with the first pile body 10, the cylindrical surface 123 extends vertically and surrounds the outer side of the first pile body 10, the diameter of the first conical surface 122 is gradually increased from top to bottom, and the diameter of the second conical surface 124 is gradually reduced from top to bottom, so that the first pile body 10 and the first annular bulge 12 can be conveniently preformed integrally and demoulded.
When the precast pile 1 is produced by using the steel die, the problem of difficult demolding easily occurs during demolding due to centrifugal integrated molding, and the problem is particularly remarkable for the bamboo joint pile with the bulge on the peripheral wall, and different types of molds are researched in the industry so as to improve the yield. In the invention, the first thickening protrusion 11 is similar to the bamboo joint part of a conventional bamboo joint pile, the first annular protrusion 12 is projected along the length direction of the first pile body 10 to completely cover the inner peripheral wall of a drilled hole and is projected along the length direction of the first pile body 10, the first annular protrusion 12 is projected along the length direction of the first pile body 10 to cover or at least partially overlap the second annular protrusion 13 and is projected along the length direction of the first pile body, namely, the outer diameters of the first annular protrusion 12 and the second annular protrusion 13 are larger than the outer diameter of the first thickening protrusion 11, so that the distribution condition of stress on the whole precast pile 1 is changed, and a new challenge is brought to demoulding.
In order to solve the technical problem of difficult demolding, an included angle between the first conical surface 122 of the first annular protrusion 12 and the second annular protrusion 13 and a horizontal plane is 45 degrees, and an included angle between the second conical surface 124 of the first annular protrusion 12 and the second annular protrusion 13 and a vertical direction is more than 45 degrees and less than 90 degrees. The arrangement makes the upper and lower end surfaces of the first annular bulge 12 not symmetrical, and the upper and lower end surfaces of the first annular bulge 12 have stress differences in local view, but the stress differences in the whole pile body can just weaken or offset the problem of uneven stress distribution caused by the size and position factors of the first annular bulge 12 to a certain extent, thereby improving the yield. Meanwhile, the included angle between the second conical surface 124 of the first annular bulge 12 and the second annular bulge 13 and the horizontal plane is reduced, so that the extrusion of the first annular bulge 12 and the second annular bulge 13 acts on the cement soil at the lower side of the first annular bulge 12 in the drilled hole as much as possible when the precast pile 1 is planted, and the extrusion effect of the first annular bulge 12 and the second annular bulge 13 on the cement soil at the lower side of the first annular bulge 12 in the drilled hole is improved.
Typically, when preparing the bamboo joint pile, the bamboo joint protrusions should be symmetrical up and down to adjust stress distribution, as shown in fig. 2, the first thickening protrusions 11 are conventional and have symmetrical upper and lower end surfaces. However, when the first annular protrusion 12 and the second annular protrusion 13 surround the outer side of the first pile body 10, and the size of the first annular protrusion 12 and the size of the second annular protrusion 13 are larger than the size of the first thickening protrusion 11, uneven stress distribution occurs from the perspective of the whole pile body of the first pile body 10, and at this time, the first annular protrusion 12 and the second annular protrusion 13 are arranged to be asymmetric upper and lower end surfaces, so that the defect of uneven distribution can be weakened or counteracted, and the technical problem of difficult demoulding is solved.
Referring to fig. 5 and 6, in other examples, in order to solve the problem of difficulty in demolding caused by uneven stress distribution, the application scenario of the precast pile 1 is enlarged, the first pile body 10 and the first thickening protrusion 11 are integrally precast, and the first annular protrusion 12 and/or the second annular protrusion 13 are welded or detachably fixed on the first pile body 10. Preferably, the first annular protrusion 12 and/or the second annular protrusion 13 comprise more than two arc-shaped protrusions 120 which can be mutually spliced to form a circular ring shape, and the arc-shaped protrusions 120 are prefabricated by concrete, so that the mass production is convenient, the corrosion is not easy, the cost is low, and the service life is long. So, in the stage of centrifugal prefabrication shaping, can be the same with current bamboo joint stake, current production mould, production operation can keep unchanged, and the stress distribution of whole precast pile 1 pile body is even, and the situation that the pile body position is broken down is difficult to appear in the drawing of patterns, can effectively reduce first annular arch 12 and the adverse effect that second annular arch 13 brought to pile body stress distribution in the centrifugal shaping stage.
Since the first annular protrusion 12 and the second annular protrusion 13 of relatively large dimensions are avoided from being prefabricated at the time of production, the first pile body 10 and the first thickening protrusion 11 can relatively easily perform the demolding action. On this basis, the shape and size of the first annular projection 12 and the second annular projection 13 can be selected more. Referring to fig. 5, preferably, the first annular protrusion 12 and/or the second annular protrusion 13 includes a first tapered surface 122', a cylindrical surface 123' and a second tapered surface 124' which are sequentially connected from top to bottom, the cylindrical surface 123' extends vertically and surrounds the outer side of the first pile body 10, an end portion of an upper end of the first tapered surface 122' is connected with the first pile body 10, an end portion of a lower end of the first tapered surface 122' is connected with the cylindrical surface 123', an end portion of an upper end of the second tapered surface 124' is connected with the first pile body 10, an end portion of a lower end of the second tapered surface 124' is connected with the cylindrical surface 123', a diameter of the first tapered surface 122' increases gradually from top to bottom, and a diameter of the second tapered surface 124' increases gradually from top to bottom, and the second tapered surface 124' cooperates with the first pile body 10 to form an annular cavity with a downward opening. When the precast pile 1 is planted, the second conical surface 124 'of the first annular protrusion 12 guides the cement soil to gather towards the first pile body 10, so that the cement soil overflows from the lower side of the first annular protrusion 12 to the upper side of the first annular protrusion 12, or overflows from the lower side of the second annular protrusion 13 to the upper side of the second annular protrusion 13, meanwhile, the acting force of the second conical surfaces 124' of the first annular protrusion 12 and the second annular protrusion 13 can completely act on the cement soil in a drilled hole, and the extrusion effect of the first annular protrusion 12 and the second annular protrusion 13 on the cement soil in the drilled hole is further improved.
In addition, the lower surface of the arc-shaped bulge 120 can be horizontally arranged, so that the acting force of the lower end surfaces of the first annular bulge 12 and the second annular bulge 13 can be kept vertically downwards as much as possible when the precast pile 1 is planted, thereby completely acting on cement soil in a drilled hole and further improving the extrusion effect of the first annular bulge 12 and the second annular bulge 13 on cement soil in the drilled hole.
Further, referring to fig. 6, the inner circumferential wall of the arc-shaped protrusion 120 has a groove 125 adapted to the first thickening protrusion 11, and the groove 125 is located at the middle of the inner circumferential wall of the arc-shaped protrusion 120. When the arc-shaped bulge 120 is fixed on the first pile body 10, the outer peripheral wall of the first thickening bulge 11 is mutually attached to the inner side wall of the groove 125 of the arc-shaped bulge 120, the arc-shaped bulge 120 is axially limited, the connection firmness of the arc-shaped bulge 120 and the first pile body 10 is improved, and when the precast pile 1 is implanted into a drilled hole, the arc-shaped bulge 120 is not easy to move along the axial direction relative to the first pile body 10.
Optionally, the first annular protrusion 12 and/or the second annular protrusion 13 are welded to the first pile body 10. Specifically, at least one of the two ends of the arc-shaped protrusion 120 is embedded with a first embedded steel member 121, where the first embedded steel member 121 may be an arc-shaped steel member, or may be composed of a plurality of arc-shaped steel sheets uniformly arranged along the circumferential direction of the arc-shaped protrusion 120, in this example, the first embedded steel member 121 is a plurality of arc-shaped steel sheets uniformly arranged along the circumferential direction of the arc-shaped protrusion 120, and the inner diameter of the arc-shaped steel sheets is equal to the inner diameter of the arc-shaped protrusion 120. Specifically, the arc-shaped steel sheet is buried in a specific position of the steel die in advance during manufacturing, and is integrally prefabricated with the arc-shaped protrusion 120.
The first pile body 10 is embedded with a second embedded steel member 14, the second embedded steel member 14 may be an annular steel member, or may be composed of a plurality of arc steel sheets uniformly arranged along the circumferential direction of the first pile body 10, in this example, the second embedded steel member 14 is set to a plurality of arc steel sheets uniformly arranged along the circumferential direction of the first pile body 10 corresponding to the first embedded steel member 121, and the outer diameter of the arc steel sheets is equal to the outer diameter of the first pile body 10. Specifically, the arc-shaped steel sheet is buried in a specific position of the steel mould in advance during manufacturing, and then centrifugal integrated prefabrication molding is carried out. The first pre-buried steel member 121 is welded to the second pre-buried steel member 14 to fix the arc-shaped protrusion 120 to the first pile body 10.
In order to ensure connection firmness, preferably, the two ends of the arc-shaped protrusion 120 are pre-embedded with the first pre-embedded steel piece 121, the upper end surface of the first pre-embedded steel piece 121 at the upper side is not lower than the upper end of the first annular protrusion 12, and the lower end surface of the first pre-embedded steel piece 121 at the lower side is not higher than the lower end of the first annular protrusion 12. The two second pre-buried steel pieces 14 are arranged corresponding to the first pre-buried steel pieces 121, the two second pre-buried steel pieces 14 are respectively positioned at two sides of a first thickening protrusion 10, and the two first pre-buried steel pieces 121 are respectively welded on the two second pre-buried steel pieces 14.
Further, a plurality of first reinforcing bars 126, first connecting ribs 127 and radial ribs 128 are embedded in the arc-shaped bulge 120, the first reinforcing bars 126 extend along the axial direction of the arc-shaped bulge 120, the plurality of first reinforcing bars 126 are uniformly arranged along the circumferential direction of the arc-shaped bulge 120, two first connecting ribs 127 are correspondingly connected with one first reinforcing bar 126, one ends of the two first connecting ribs 127 are respectively connected with two ends of the first reinforcing bars 126, the first connecting ribs 127 at the upper end are parallel to the upper end face of the arc-shaped bulge 120, the other ends of the first connecting ribs 127 at the upper end are welded and fixed with the first embedded steel part 121 at the upper side, the first connecting ribs 127 at the lower end are parallel to the lower end face of the arc-shaped bulge 120, and the other ends of the first connecting ribs 127 at the lower end are welded and fixed with the first embedded steel part 121 at the lower side. The first reinforcement bar 126 and the first connecting rib 127 are completely embedded in the arc-shaped protrusion 120, the binding force with the arc-shaped protrusion 120 is stronger, and the first embedded steel piece 121 is connected with the first connecting rib 127, so that the first embedded steel piece 121 is connected with the arc-shaped protrusion 120 more firmly. The first reinforcing steel bar 126 is further welded with a plurality of radial ribs 128, the radial ribs 128 extend along the radial direction of the arc-shaped protrusions 120, the radial ribs 128 are evenly distributed along the length direction of the first reinforcing steel bar 126, the first reinforcing steel bar 126 and the radial ribs 128 are matched to serve as a skeleton of the arc-shaped protrusions 120, the structure of the arc-shaped protrusions 120 is reinforced, the load bearing capacity of the arc-shaped protrusions 120 is improved, and the arc-shaped protrusions 120 are not prone to cracking and damaging when the precast pile 1 is implanted into a drilled hole.
Further, a plurality of second reinforcing bars 16 and second connecting bars 161 are embedded in the first pile body 10, the second reinforcing bars 16 extend vertically, the plurality of second reinforcing bars 16 are uniformly distributed along the circumferential direction of the first pile body 10, and the second reinforcing bars 16 are fastened on the prestressed main bars 15 of the first pile body 10 through the hoops 151. The two second connecting ribs 161 are correspondingly connected with one second steel bar 16, one ends of the two second connecting ribs 161 are respectively connected with two ends of the second steel bar 16, the other end of the second connecting rib 161 at the upper end is welded and fixed with the second embedded steel piece 14 at the upper side, and the other end of the second connecting rib 161 at the lower end is welded and fixed with the second embedded steel piece 14 at the lower side. The second steel bar 16 and the second connecting rib 161 are completely embedded in the first pile body 10, the binding force with the first pile body 10 is stronger, the second embedded steel piece 14 is connected with the second connecting rib 161, so that the second embedded steel piece 14 is more firmly connected with the first pile body 10, and meanwhile, the second embedded steel piece 14 is conveniently fixed on the prestress main rib 15 of the steel bar cage for fixation and positioning before embedding.
Compared with the first annular bulge 12 and the second annular bulge 13 which are integrally prefabricated and formed with the first pile body 10, the welding and forming mode can well expand the application scene. Due to different construction environments, the physical properties of the foundation are different, and the balance between improving the extrusion effect and controlling the soil extrusion effect can be achieved by adjusting the dimension specifications of the first annular protrusion 12 and the second annular protrusion 13. For example, the first annular protrusion 12 and the second annular protrusion 13 (more than two arc-shaped protrusions 120 spliced with each other) with different dimensions are welded and fixed on the second embedded steel member 14 of the first pile body 10. In general, when the foundation contains a soil layer with sand, gravel, cobble and a larger-volume stone, the drilling difficulty is larger, the hole wall is easy to be interfered by external force, the first annular bulge 12 and the second annular bulge 13 with smaller sizes are suitable for extruding the cement soil at the moment, and when the foundation contains a soil layer with more clay and silt, the soil layer gaps are fewer, the cement soil permeation difficulty is larger, and the first annular bulge 12 and the second annular bulge 13 with larger sizes are suitable for extruding the cement soil at the moment.
Referring to fig. 7, alternatively, the first annular protrusion 12 and the second annular protrusion 13 are both detachably fixed to the first pile body 10. Specifically, the first thickening protrusion 11 is provided with a bolt hole 112 extending in a radial direction, the arc protrusion 120 is provided with a through hole 129 corresponding to the bolt hole 112, after the arc protrusion 120 abuts against the outer side of the first thickening protrusion 11, the expandable end of the expansion bolt 17 is inserted into the bolt hole 112 through the through hole 129, and the two arc protrusions 120 are fixed on the first thickening protrusion 11 by rotating the nut of the expansion bolt 17. In order to ensure the extrusion effect, the first annular protrusion 12 is preferably detachably fixed to the outer side of the first thickening protrusion 11 on the side of the first pile body 10 closest to the pile cap.
In this example, since the first annular projection 12 and the second annular projection 13 of relatively large dimensions are avoided from being prefabricated at the time of production, the first pile body 10 and the first thickening projection 11 can perform the demolding operation relatively easily. On the basis of this, the shape of the first annular projection 12 and the second annular projection 13 can also be chosen more. Meanwhile, due to the fact that embedded parts such as the second embedded steel part 14 and the first embedded steel part 121 are prevented from being embedded in production, the first pile body 10 and the first thickening protrusion 11 can be prefabricated and formed integrally relatively easily, and the first annular protrusion 12 can also be prefabricated and formed relatively easily and independently. Furthermore, the first annular projection 12 and the second annular projection 13 are connected to the first thickened projection 11 by the expansion bolts 17, and the assembly is simpler.
Based on the foregoing thought, in order to further solve the problem of difficulty in demolding caused by uneven stress distribution, and expand the applicable scenario of the precast pile 1, referring to fig. 8, in some examples, a projection of an outer peripheral wall of an end plate of the first end 10 'of the first pile body 10 along the length direction of the first pile body 10 surrounds an outer side of the projection of the first pile body 10 along the length direction, and a portion of the end plate of the first end 10' of the first pile body 10 extending out of the first pile body 10 forms a first annular protrusion 12. Specifically, when precast pile 1 prefabricates the shaping in an organic whole, connect the end plate of standard specification in the one end of the steel reinforcement cage of first pile body 10, the external diameter of end plate of standard specification equals the external diameter of first pile body 10, connect the end plate of bigger specification at the other end of the steel reinforcement cage of first pile body 10, the external diameter of the end plate of bigger specification is greater than the external diameter of first pile body 10.
Since the first annular protrusion 12 of a relatively large size is prevented from being prefabricated at the time of production, the first pile body 10 and the first thickening protrusion 11 can relatively easily perform the demoulding action without requiring the subsequent assembly. On the basis of this, the shape of the first annular projection 12 can also be chosen more.
Based on the foregoing thought, in order to further solve the problem of difficulty in demolding caused by uneven stress distribution, and expand the application scenario of the precast pile 1, referring to fig. 9 and 10, in some examples, the first annular protrusion 12 is arranged in an end plate shape, a plurality of penetrating holes 129' are formed in the first annular protrusion 12 at intervals, the penetrating holes 129' penetrate through the upper end surface and the lower end surface of the first annular protrusion 12, correspondingly, threaded holes 19 are formed in the end plate of the first end 10' of the first pile body 10, and the studs of the bolts 18 are in threaded connection with the threaded holes 19 after penetrating through the penetrating holes 129', so as to fixedly connect the first annular protrusion 12 to the first end 10' of the first pile body 10.
Since the first annular projection 12 of a relatively large size is avoided from being prefabricated at the time of production, the first pile body 10 and the first thickening projection 11 can perform the demoulding operation relatively easily. During construction, the first annular bulge 12 is detachably fixed at the first end 10 'of the first pile body 10 through the bolts 18, the first annular bulge 12 can be installed after the first end 10' of the precast pile 1 passes through the pile clamping box, interference between the first annular bulge 12 and the pile clamping box is avoided, and further the pile clamping box is not required to be refitted, so that the construction cost of the precast pile 1 is reduced, meanwhile, the first annular bulge 12 is conveniently detached and recycled before bearing platform construction is carried out after excavation, and the construction cost of the precast pile 1 is further reduced.
Referring to fig. 10 and 11, further, the threaded hole 19 is an anchoring hole of the end plate of the first end 10' of the first pile body 10. Specifically, taking the end plate of the first end 10 'as a circular end plate for example, the end plate of the first end 10' is provided with an anchoring hole, the anchoring hole is a threaded hole 19 so as to be connected with a tensioning bolt, and tensioning of the reinforcement cage is facilitated, the threaded hole 19 penetrates through two end surfaces of the end plate of the first end 10 'along the length direction of the first pile body 10, and the diameter of the threaded hole 19 is larger than that of the upsetting head so that the upsetting head can penetrate through the threaded hole 19 along the direction from the second end 10″ to the first end 10'. The end plate of the first end 10' is further provided with a bar passing hole 191 which is arranged in a strip shape, the bar passing hole 191 penetrates through two end surfaces of the end plate of the first end 10' along the length direction of the first pile body 10, the bar passing hole 191 extends along the circumferential direction of the end plate of the first end 10', one end of the bar passing hole 191 is communicated with the anchoring hole, and the width of the bar passing hole 191 is larger than the diameter of the main bar and smaller than the diameter of the upsetting head. The end plate of the first end 10' is further provided with a hanging rib hole, the hanging rib hole is communicated with the other end of the through rib hole 191, the hanging rib hole is a stepped hole, the hanging rib hole comprises a large-diameter hole 192 and a small-diameter hole 193, an opening of the large-diameter hole 192 is arranged away from the first pile body 10, an opening of the small-diameter hole 193 is arranged towards the first pile body 10, the diameter of the large-diameter hole 192 is larger than that of the small-diameter hole 193, the diameter of the large-diameter hole 192 is larger than that of the upsetting head, the diameter of the small-diameter hole 193 is larger than that of the main rib and smaller than that of the upsetting head, and the upsetting head can be clamped in the large-diameter hole 192. When the main rib is assembled with the end plate of the first end 10', the upsets pass through the threaded holes 19 in the direction from the second end 10' to the first end 10', then the end plate of the first end 10' is rotated, the main rib moves to the other end of the rib passing hole 191, the end plate of the first end 10' is moved in the direction from the second end 10' to the first end 10', and the upsets are clamped in the large-diameter holes 192.
The first annular protrusion 12 is fixedly connected to the first end 10' of the first pile body 10 by directly using the anchor hole-matching bolts 18, and the threaded holes 19 are not required to be additionally machined in the end plate, so that the machining steps are simplified, and the production cost of the precast pile 1 is reduced.
When the outer diameters of the first and second annular protrusions 12 and 13 are larger than the bore diameter, additional downward pile-feeding pressure is required to achieve the implantation of the precast pile 1 into the bore. As described above, the second annular projection 13, the outer peripheral wall of the first pile body 10 and the borehole wall form a closed cavity therebetween, in which case a pile delivery difficulty may occur when a pressure is applied to deliver the pile downward. For this purpose, referring to fig. 12, in some examples, at least one pressure relief channel 131 is provided on the second annular protrusion 13, and the pressure relief channel 131 penetrates the second annular protrusion 13 along the length direction of the first pile body 10. Further, the second annular protrusion 13 is provided with more than two pressure relief channels 131 evenly distributed along the circumferential direction, the pressure relief channels 131 can be through holes or openings, and can also be combinations of the through holes and the openings, and the combinations can be specifically set according to the influence degree of the pile foundation construction environment on the surrounding environment. When the pressure release channels 131 are openings, the radial dimension of the pressure release channels 131 is not smaller than 50mm, and the arc length of each pressure release channel 131 is not larger than 1/15 of the circumference of the drill hole and not smaller than 1/20 of the circumference of the drill hole. When the pressure release channel 131 is a notch, the projection part of the outer peripheral wall of the first annular bulge 12 along the length direction of the first pile body 10 is overlapped with the projection part of the outer peripheral wall of the second annular bulge 13 along the length direction of the first pile body 10, and when the pressure release channel 131 is a through hole, the projection part of the outer peripheral wall of the first annular bulge 12 along the length direction of the first pile body 10 is completely overlapped with the projection part of the outer peripheral wall of the second annular bulge 13 along the length direction of the first pile body 10.
When the first pile body 10 is sent downwards, a part of cement soil can be transferred to the upper end of the second annular bulge 13 through the pressure release channel 131, so that the pressure load of the lower end face of the second annular bulge 13 is reduced to a certain extent, the pressure control is facilitated, and balance is achieved between the reduction of the holding pressure applied when the precast pile 1 is implanted and the improvement of the extrusion effect. Whether the second annular bulge 13 is provided with the pressure relief channel 131 and the number and the size of the pressure relief channels 131 can be set according to the influence degree of the pile foundation construction environment on the surrounding environment. Still further, possess the protruding 13 of second annular of pressure release passageway 131 in this example, be fit for using the mode that forms the protruding 13 of second annular through welding or bolt fastening mode after first pile body 10 and the protruding 11 of first thickening are prefabricated integratively, with the protruding 13 lower terminal surface level of second annular set up or indent setting simultaneously, the effort of the protruding 13 lower terminal surface of second annular can keep vertical downwards as far as possible when the precast pile is planted to the soil cement in the complete acting on drilling, further improve the protruding 13 extrusion effect to the soil cement in the drilling of second annular. According to the soil layer actual condition, the construction soil extrusion condition and the cement soil extrusion action condition, the second annular protrusions 13 with different sizes, different shapes and pressure relief channels 131 are selected to be installed on the first pile body 10 of the precast pile 1, so that the soil extrusion effect and the cement soil extrusion effect can be effectively balanced, and the operation complexity of construction, production and preparation is also considered.
In addition, the first pile body 10 may be provided with a regular polygon cross-section outer contour, such as a square, the first thickening protrusion 11, the first annular protrusion 12 and the second annular protrusion 13 may be provided with circular rings, or may be provided with a regular polygon ring corresponding to the first pile body 10 cross-section outer contour, and the first thickening protrusion 11, the first annular protrusion 12 and the second annular protrusion 13 may be provided with a regular polygon ring corresponding to the first pile body 10 cross-section outer contour, where the first thickening protrusion 11, the first annular protrusion 12 and the second annular protrusion 13 are all parallel around the outer side of the first pile body 10. However, it should be noted that, no matter what shape is adopted, in order to ensure the extrusion effect of the first annular protrusion 12 on the cement in the hole, and to improve the extrusion effect by using the closed cavity, the projection of the first annular protrusion 12 along the length direction of the first pile body 10 completely covers the projection of the inner peripheral wall of the drilled hole along the length direction of the first pile body 10. Referring to fig. 13, in some examples, the first pile body 10 is a hollow square pile, the first thickening protrusion 11, the first annular protrusion 12 and the second annular protrusion 13 are all square annular, the first thickening protrusion 11, the first annular protrusion 12 and the second annular protrusion 13 are all parallel around the outer side of the first pile body 10, the distance from the outer circumferential wall of the first pile body 10 to the outer circumferential wall of the first thickening protrusion 11 is 50mm to 150mm, the distance from the outer circumferential wall of the first pile body 10 to the outer circumferential wall of the first annular protrusion 12 is 90mm to 200mm, and the distance from the outer circumferential wall of the first thickening protrusion 11 to the outer circumferential wall of the first annular protrusion 12 is 40mm to 150mm. The first thickening protrusion 11 is provided on an outer peripheral wall thereof with a concave groove 111, the concave groove 111 extending in a horizontal direction. Due to the arrangement of the concave groove 111, on one hand, after the precast pile 1 is implanted into a drilled hole, cement soil can fill the concave groove 111, so that the embedding effect between the precast pile 1 and the cement soil is improved, the limit friction resistance of an interface S1 between the pile body of the precast pile 1 and solidified soil around the pile is increased, the single pile bearing capacity of the precast pile 1 after implantation is further improved, and on the other hand, the friction coefficient between the first pile body 10 and the transverse clamp can be increased during holding and pressing construction.
In summary, the working principle of the precast pile of the above embodiment is that as the precast pile 1 is continuously planted in the drilled hole, the lower end faces of the first annular protrusion 12 and the second annular protrusion 13 continuously squeeze the cement soil in the drilled hole at the lower side, so as to increase the pressure intensity in the drilled hole at the lower end face lower side of the first annular protrusion 12 and the lower end face lower side of the second annular protrusion 13, so that the cement soil diffuses towards the soil around the drilled hole, cement soil ions enter into the soil gaps, the bonding strength between the solidified soil around the pile and the undisturbed soil around the hole wall is further improved, the limit friction resistance of the interface S2 between the solidified soil around the pile and the undisturbed soil around the hole wall is increased, the single pile bearing capacity after the precast pile is planted is improved, in addition, the density of the cement soil is increased after being squeezed by the first annular protrusion 12 and the second annular protrusion 13, the acting force between the first thickening protrusion 11 below the first annular protrusion 12 and the cement soil can be increased, and the limit friction resistance of the interface S1 between the precast pile and the solidified soil around the pile is further improved.
On the basis of improving the extrusion effect on the cement soil, the above embodiment is also specially provided with the dimensions of the first annular protrusion 12 and the second annular protrusion 13 or the relationship between the dimensions of the first annular protrusion 12 and the second annular protrusion 13 and the dimensions of the first thickening protrusion 11 and the bore diameter in order to consider the factors of construction complexity, soil extrusion effect and the like. On the basis of improving the extrusion effect on the cement soil, the soil extrusion effect is controlled, and the construction complexity is reduced.
On the basis of improving the extrusion effect on the cement soil, the above embodiment also specially sets the shapes of the upper and lower end surfaces of the first annular protrusion 12 and the second annular protrusion 13 to weaken or offset the problem of uneven stress distribution caused by the sizes of the first annular protrusion 12 and the second annular protrusion 13 by the stress difference formed by the upper and lower end surfaces in order to improve the yield in the production of the product and reduce the complexity of the preparation operation. In addition, the first pile body 10 and the first thickening protrusion 11 are integrally prefabricated and formed, and the first annular protrusion 12 and the second annular protrusion 13 are welded or bolted and formed, so that the problem of difficult demoulding caused by uneven stress distribution is avoided.
The above embodiment also provides a preferred mode by comprehensively considering the construction operation complexity, the preparation operation complexity, the soil squeezing effect and the extrusion effect on the cement soil, after the first pile body 10 and the first thickening protrusion 11 are integrally prefabricated and formed, the second annular protrusion 13 is formed into the second annular protrusion 13 with the pressure relief channel 131 by welding or bolting and forming, so that the construction and preparation operation complexity is controlled to be minimum, and the soil squeezing effect and the extrusion effect on the cement soil are balanced.
Example 2
Referring to fig. 14-16, the embodiment of the application discloses a composite pile.
Referring to fig. 14, the composite pile of the present embodiment includes a top precast pile and at least one bottom precast pile 2 connected to a lower end of the top precast pile. The top precast pile 1 is constituted by the precast pile 1 described in embodiment 1, and the precast pile 1 includes a first pile body 10, a plurality of first thickening protrusions 11, and a first annular protrusion 12. The first pile body 10 is a pipe pile and is formed by integrally prefabricating concrete, the first pile body 10 extends vertically, a plurality of first thickening protrusions 11 are fixed on the outer peripheral wall of the first pile body 10, a plurality of first thickening protrusions 11 are arranged at intervals along the length direction of the first pile body 10, and the inner peripheral wall of a drilled hole is formed around the outer side of the first pile body 10 and the first thickening protrusion 11 assembly along the length direction projection of the first pile body 10. The first annular bulge 12 is fixedly arranged on the first pile body 10 in a surrounding mode, the first annular bulge 12 is located above at least one first thickening bulge 11, and the first annular bulge 12 is projected along the length direction of the first pile body 10 to completely cover the inner peripheral wall of the drilled hole and is projected along the length direction of the first pile body 10. The first annular protrusion 12 may be integrally preformed with the first pile body 10 and the first thickening protrusion 11, or may be preformed first and then welded or bolted to the first pile body 10, or may be directly formed by a portion of the first end 10 'extending out of the first pile body 10 or bolted to an end plate of the first end 10' of the first pile body 10 in the form of a metal end plate, which is specifically referred to in the related description in embodiment 1 and will not be repeated herein.
In some examples, the bottom precast pile 2 includes a second pile body 20, the second pile body 20 extends vertically and is precast integrally with concrete, and the projection of the outer circumferential wall of the second pile body 20 along the length direction of the first pile body 10 is completely coincident with the projection of the outer circumferential wall of the first pile body 10 along the length direction of the first pile body 10. Alternatively, the first pile body 10 and the second pile body 20 may be hollow round piles, or tubular piles with regular polygon cross section outline, or solid piles, which may be specifically selected according to construction requirements.
When the precast pile 1 is implanted into a drilled hole, the lower end face of the first annular bulge 12 is used for extruding cement soil in the drilled hole at the lower side of the first annular bulge 12 so as to increase the pressure intensity in the drilled hole at the lower side of the lower end face of the first annular bulge 12, so that cement soil is diffused to the soil around the drilled hole, cement soil ions enter into soil gaps, the bonding strength between the solidified soil around the pile and the undisturbed soil on the hole wall is improved, the limit friction S2 between the solidified soil around the pile and the undisturbed soil around the hole wall is increased, and the single pile bearing capacity of the assembled pile after implantation is improved. In addition, the acting force of the cement soil after extrusion in the drilled hole and the first thickening protrusion 11, the first pile body 10 and the second pile body 20 is increased, the limit friction resistance of the interface S1 between the part of the pile body of the combined pile and the solidified soil around the pile is increased, and the single pile bearing capacity of the combined pile after implantation is further improved.
In some examples, the bottom precast pile 2 includes a second pile body 20 and a plurality of second thickening protrusions 21. The second pile body 20 extends vertically and is formed by integrally prefabricating concrete, the second thickening protrusions 21 and the second pile body 20 are formed integrally in prefabricating mode, the second thickening protrusions 21 are uniformly distributed along the length direction of the second pile body 20, and the projection of the outer peripheral wall of each second thickening protrusion 21 along the length direction of the first pile body 10 coincides with the projection of the outer peripheral wall of each first thickening protrusion 11 along the length direction of the first pile body 10. Alternatively, the first pile body 10 and the second pile body 20 may be hollow round piles, or may be hollow square piles, or may be solid square piles or solid round piles, which may be specifically selected according to the construction requirement.
Due to the effect of the second thickening protrusions 21, the contact surface of the interface S1 between the combined pile and the cement soil is increased, the stress direction is increased, the peak stress of the interface is improved, the limit friction resistance of the interface S1 between the pile body of the part of the combined pile and the solidified soil around the pile is increased, and the single pile bearing capacity of the combined pile after being implanted is further improved.
In other examples, the plurality of bottom precast piles 2 may be a combination of tubular piles and special-shaped piles with alternating thicknesses along the length direction, that is, the bottom precast pile 2 at the lowest end is a special-shaped pile with alternating thicknesses along the length direction, for example, a bamboo pile, and a plurality of cylindrical tubular piles or a combination of bamboo piles and cylindrical tubular piles are connected between the bamboo pile at the lowest end and the top precast pile, and the configuration may be specifically selected according to the actual construction environment and the construction requirement.
Referring to fig. 15, in some examples, the bottom precast piles 2 are tubular structures having inner cavities, such as hollow round piles, hollow square piles, and a blocking structure for at least partially blocking the inner cavities of the bottom precast piles 2 is fixed to at least one of the bottom precast piles 2 to adjust the pressure in the drilled hole at the lower side of the first annular protrusion 12, thereby controlling the squeezing effect of cement in the drilled hole. The end sealing plate 3 of the end portion of the bottom precast pile is arranged at the end sealing plate 3, the end sealing plate 3 is fixedly welded at the end portion of one bottom precast pile 2, the end sealing plate 3 is provided with a pressure regulating hole 30 which is vertically communicated with an inner hole of the second pile body 20, the diameter of the pressure regulating hole 30 is smaller than the inner diameter of the second pile body 20, the pressure regulating hole 30 is used for preventing cement paste from passing through the pressure regulating hole 30 and allowing air to pass through the pressure regulating hole 30 so as to regulate the pressure intensity in a drilled hole at the lower side of the first annular bulge 12, and the extrusion effect of cement paste in the drilled hole is controlled. Under the same conditions, the closer the position of the end sealing plate 3 is to the bottom of the drilled hole, the more cement soil is between the peripheral wall of the first pile body 10, the peripheral wall of the second pile body 20 and the side wall of the drilled hole, the greater the pressure intensity in the drilled hole at the lower side of the first annular bulge 12, and the height of the end sealing plate 3 can be adjusted and set according to the influence of pile foundation construction on the surrounding environment.
In addition, the plugging structure can be replaced by setting one of the bottom precast piles 2 to be a solid pile, so that the amount of cement slurry entering the bottom precast pile 2 is regulated, the pressure in the drilled hole at the lower side of the first annular bulge 12 is regulated, and the extrusion effect on the cement slurry in the drilled hole is controlled.
Referring to fig. 16, in some examples, the composite pile further includes a constant section pipe pile 4, the constant section pipe pile 4 extends vertically and is integrally prefabricated and formed by concrete, the projection of the outer circumferential wall of the constant section pipe pile 4 along the length direction of the first pile body 10 is completely overlapped with the projection of the outer circumferential wall of the first annular protrusion 12 along the length direction of the first pile body 10, and the constant section pipe pile 4 is welded and fixed to the upper end of the top precast pile. Specifically, one of the first annular protrusions 12 is disposed at the uppermost end of the first pile body 10, the first annular protrusion 12 and the first pile body 10 are integrally preformed, the upper end face, the outer peripheral face and the lower end face of the first annular protrusion 12 are sequentially connected from top to bottom, the upper end face of the first annular protrusion 12 extends from the outer peripheral face to the first pile body 10, the upper end face of the first annular protrusion 12 is coplanar with the upper end face of the first pile body 10, the outer peripheral face of the first annular protrusion 12 extends vertically and surrounds the outer side of the first pile body 10, the lower end face of the first annular protrusion 12 extends from the outer peripheral face to the first pile body 10, the lower end face of the first annular protrusion 12 is in a conical surface arrangement, the diameter of the lower end face of the first annular protrusion 12 gradually decreases from top to bottom, and the upper end of the first annular protrusion 12 is provided with an end plate for connecting the tubular pile 4 with a uniform section. Preferably, the first annular protrusion 12 of the precast pile 1 is one and is provided at the uppermost end of the first pile body 10 in this example.
The first annular bulge 12 is made into an enlarged head of the precast pile 1 and is used for connecting the equal-section tubular pile 4 with the outer diameter equal to that of the first annular bulge 12, the equal-section tubular pile 4 is tightly matched with soil around a drilling hole wall, the cement soil is not easy to overflow upwards, on one hand, the extrusion effect of the combined pile on the cement soil in the drilling hole is improved, the cement soil quantity of soil gaps around the drilling hole wall is increased, the bonding strength between the solidified soil around the pile and original soil around the hole wall is improved, the limit friction force of an interface S2 between the solidified soil around the pile and the original soil around the hole wall is improved, the single pile bearing capacity after the combined pile is implanted is further improved, on the other hand, the cement soil density at the lower side of the first annular bulge 12 is further increased along with the improvement of the extrusion effect of the combined pile on the cement soil in the drilling hole wall, the acting force among the first thickened bulge 11, the first pile body 10, the second pile body 20 and the surrounding cement soil is further improved, the limit friction force of the precast pile 1, the interface S1 among the solidified soil around the precast pile 2 and the pile is further improved, the single pile bearing capacity after the combined pile is implanted is further improved, and the horizontal bearing capacity after the combined pile is further improved through the connection of the equal-section tubular pile 4.
In summary, the working principle of the composite pile of the above embodiment is that the size of the drilled hole is designed according to the cross-sectional size of the first pile body 10 of the precast pile 1, the orthographic projection of the inner peripheral wall of the drilled hole on the horizontal plane surrounds the outer side of the orthographic projection of the combination of the first pile body 10 and the first thickening protrusion 11, and the orthographic projection of the inner peripheral wall of the drilled hole on the horizontal plane is completely covered by the orthographic projection of the first annular protrusion 12 on the horizontal plane; the method comprises the steps of drilling a hole by a drilling machine to a designed depth, injecting a certain volume of solidified slurry into a pile end, injecting a certain volume of solidified slurry into a part above the pile end, stirring with soil in a hole to form a state between liquid state and solid state, sequentially and sectionally implanting a bottom precast pile 2 into the hole by means of dead weight and pile pressing force, welding a precast pile 1 onto the upper end of the uppermost bottom precast pile 2, pressing the precast pile 1 into the hole, continuously extruding cement soil in the lower side hole by the lower end surface of a first annular bulge 12 along with the continuous implantation of the precast pile 1 to increase the pressure intensity in the lower side hole of the lower end surface of the first annular bulge 12, so that cement soil is diffused into soil gaps around the hole, the bonding strength between the solidified soil around the pile and the soil around the hole is improved, the limit resistance of an interface S2 between the solidified soil around the pile and the soil around the hole is increased, the single pile bearing force after the cement soil is extruded by the first annular bulge 12 is increased, the density of the cement soil is increased, the interface between the first annular bulge 11 and the first pile and the second pile is increased, the limit resistance between the first pile and the solidified pile is increased, the interface S is increased, the friction force between the cement pile and the first pile is increased, the interface between the first pile and the first pile body and the solidified pile body is increased, and further improves the bearing capacity of the single pile after the combined pile is implanted.
Example 3
The embodiment of the application discloses a construction method of a composite pile by applying the composite pile in the embodiment 2, which comprises the following steps:
s1, drilling, namely designing the size of a drilling hole according to the cross section size of a first pile body 10 of a precast pile 1, wherein the orthographic projection of the inner peripheral wall of the drilling hole on the horizontal plane surrounds the outer side of the orthographic projection of the combined body of the first pile body 10 and a first thickening protrusion 11 on the horizontal plane, and the orthographic projection of the inner peripheral wall of the drilling hole on the horizontal plane is completely covered by the orthographic projection of a first annular protrusion 12 on the horizontal plane;
S2, drilling construction, namely drilling according to the drilling arrangement, wherein in FIG. 16 (1), drilling is carried out to the design depth;
S3, planting and grouting the bottom precast piles 2, namely injecting curing slurry into a drilled hole and placing at least one bottom precast pile 2 into the drilled hole, wherein in the steps (2) - (4) in FIG. 17, a certain volume of curing slurry is injected into a pile end, then a certain volume of curing slurry is injected into a part above the pile end, the curing slurry and soil in the drilled hole are stirred to form a state between a liquid state and a solid state, and then the at least one bottom precast pile 2 is placed into the drilled hole in a segmented mode by virtue of dead weight and pile pressing force;
s4, pile planting is carried out on the top precast pile, namely the precast pile 1 is placed at the upper end of the bottom precast pile 2 at the uppermost end, and the precast pile 1 is pressed into a drilled hole, wherein the first annular bulge 12 and the second annular bulge 13 squeeze soil mass and/or solidified slurry on the surrounding wall of the drilled hole in the process of placing the precast pile 1 into the drilled hole, and the steps are shown in (5) - (6) in fig. 16.
When the precast pile 1 is implanted into a drilled hole, as the orthographic projection of the first annular bulge 12 on the horizontal plane completely covers the orthographic projection of the inner peripheral wall of the drilled hole on the horizontal plane, in the downward implantation process, the lower end face of the first annular bulge 12 extrudes cement soil positioned at the lower side of the first annular bulge 12 in the drilled hole, the cement soil is enabled to diffuse towards the soil around the drilled hole by increasing the compression strength, part of the cement soil enters into soil gaps around the hole wall, the bonding strength between the solidified soil around the pile and the undisturbed soil of the hole wall is further improved, the limit friction resistance of an interface S2 between the solidified soil around the pile and the undisturbed soil around the hole wall is further improved, and the single pile bearing capacity of the assembled pile after implantation is further improved.
Further, in step S3, the bottom precast pile 2 is planted and still includes that one of them bottom precast pile 2 is solid pile, or bottom precast pile 2 is hollow pile, at the tip welding end shrouding 3 of one of them bottom precast pile 2, the outer peripheral wall of end shrouding 3 is along first pile body 10 length direction projection and the outer peripheral wall of second pile body 20 along first pile body 10 length direction projection coincidence completely, end shrouding 3 is equipped with the pressure regulating hole 30 that link up from top to bottom, pressure regulating hole 30 and the hole intercommunication of second pile body 20, the diameter of pressure regulating hole 30 is less than the internal diameter of second pile body 20, in order to prevent soil cement from passing through pressure regulating hole 30 from bottom to top. The end sealing plates 3 or the solid piles serve as plugging structures to adjust the volume of cement soil entering the bottom precast pile 2, and then the extrusion effect of the first annular protrusions 12 of the precast pile 1 on cement soil in the drilled holes is adjusted. In addition, when the bottom precast pile 2 is a hollow pile, the plugging structure can be further arranged in the inner hole of the bottom precast pile 2 to adjust the extrusion action of the first annular protrusion 12 of the precast pile 1 on the cement in the drilled hole.
Further, in step S3, a certain volume of solidified slurry is injected into the borehole, so that the surface of the solidified slurry is pressed into contact with the second annular protrusion 13 or the first annular protrusion 12 before the precast pile 1 is completely pressed into the borehole.
In some examples, in step S3, the injection amount of the cured slurry is the borehole volume in the height range of 2.5m to 3m at the lower end of the borehole.
In some examples, the length range of 2.6 meters of the bottom of a section of the bottom precast pile 2 which is first put into the drilled hole is provided with at least four second thickening protrusions 21, see (2) to (3) in fig. 18;
in some examples, step S2 further includes performing an expanded diameter drilling at the bottom of the drilling hole, and the drilling cavity portion of the expanded diameter drilling hole accommodates at least four second thickening protrusions 21, see fig. 19, of the bottom of a section of the bottom precast pile 2 that is first inserted into the drilling hole.
In some examples, the depth of the expanded bore is greater than 2 meters and less than 3 meters, preferably greater than 2.4 meters and less than 2.8 meters. Wherein the ratio of the expanded borehole diameter to the borehole diameter is between 1.2 and 1.4.
Further, in step S3, the injection amount of the solidified slurry is the expanded drill hole volume. The injection amount of the solidified slurry can be increased by expanding the bottom of the drilled hole and the second thickening protrusions 21 at the lower section of the precast pile 2 at the bottom of the section of the drilled hole are arranged more densely in cooperation with the first precast pile, so that the bearing capacity of the lower end of the combined pile can be further improved, and the vertical bearing capacity of the single pile after the combined pile is implanted is further improved.
In the description of the embodiments of the present application, it should be noted that, in the description of the present application, terms such as "inner", "outer", and the like, refer to directions or positional relationships based on the directions or positional relationships shown in the drawings, which are merely for convenience of description, and do not indicate or imply that the apparatus or components must have a specific orientation, be constructed and operated in a specific orientation, and thus are not to be construed as limiting the present application.
In the description of the present application, the descriptions of the terms "one embodiment," "some embodiments," "in this embodiment," "specific examples," or "some examples," etc., mean that a particular feature, mechanism, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present application. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, mechanisms, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, the different embodiments or examples described in this specification and the features of the different embodiments or examples may be combined and combined by those skilled in the art without contradiction.
The foregoing is merely illustrative of the present application, and the present application is not limited thereto, and any changes or substitutions easily contemplated by those skilled in the art within the scope of the present application should be included in the present application. Therefore, the protection scope of the application is subject to the protection scope of the claims.
Claims (35)
1. A precast pile, characterized by comprising:
The pile comprises a first pile body (10), wherein two ends of the first pile body (10) along the length direction are respectively a first end (10 ') and a second end (10');
a plurality of first thickening protrusions (11) fixed to the outer peripheral wall of the first pile body (10) and arranged at intervals along the longitudinal direction of the first pile body (10), and
-A first annular projection (12) circumferentially fixed to said first pile body (10), at least one of said first thickening projections (11) being located between said first annular projection (12) and said second end (10 ");
When precast pile (1) are put into the drilling, the inner peripheral wall of drilling is followed first pile body (10) length direction projection centers on in first pile body (10) and first thickening protruding (11) assembly are followed the outside of first pile body (10) length direction projection, first annular protruding (12) are followed first pile body (10) length direction projection covers completely the inner peripheral wall of drilling is followed first pile body (10) length direction projection.
2. A precast pile according to claim 1, characterized in that the precast pile further comprises at least one second annular projection (13) circumferentially fixed on the outer circumferential wall of the first pile body (10), the second annular projection (13) being located between the first annular projection (12) and the second end (10 "), the first annular projection (12) being projected in the length direction of the first pile body (10) over the second annular projection (13) being projected in the length direction of the first pile body (10) and the outer circumferential wall of the second annular projection (13) being projected in the length direction of the first pile body (10) being located outside the bore being projected in the length direction of the first pile body (10), or the outer circumferential wall of the first annular projection (12) being projected in the length direction of the first pile body (10) at least partially coinciding with the outer circumferential wall of the second annular projection (13) being projected in the length direction of the first pile body (10).
3. A precast pile according to claim 2, characterized in that the second annular protrusion (13) is provided with at least one pressure relief channel (131), the pressure relief channel (131) penetrating the second annular protrusion (13) along the length direction of the first pile body (10);
And/or at least one first thickening protrusion (11) is arranged between the first annular protrusion (12) and the second annular protrusion (13).
4. A precast pile according to claim 3, characterized in that the second annular protrusion (13) is provided with more than two pressure relief channels (131) circumferentially spaced apart, and/or that at least one of the pressure relief channels (131) is a through hole or a gap.
5. A preformed pile according to claim 2, characterised in that the first pile body (10) is preformed integrally with the first thickening protrusion (11), the first annular protrusion (12), the second annular protrusion (13);
The utility model discloses a pile structure, including first pile body (10), second pile body (10), first pile body (10) are hollow circular pile setting, a plurality of first thickening arch (11) are followed the length direction of first pile body (10) is the bamboo joint form setting, first annular arch (12) with second annular arch (13) all are the ring form setting, first thickening arch (11) first annular arch (12) second annular arch (13) with first pile body (10) are coaxial setting.
6. A preformed pile according to claim 2, characterised in that the first pile body (10) is preformed integrally with the first thickening protrusion (11), the first annular protrusion (12), the second annular protrusion (13);
The first pile body (10) is a hollow square pile, the first thickening protrusion (11) and the first annular protrusion (12) and the second annular protrusion (13) are all square annular, and the first thickening protrusion (11), the first annular protrusion (12) and the second annular protrusion (13) are all parallel and surround the outer side of the first pile body (10).
7. A precast pile according to claim 2, wherein the first pile body (10) and the first thickening protrusions (11) are integrally precast and formed, the first pile body (10) is arranged in a hollow round pile, and a plurality of the first thickening protrusions (11) are arranged in a bamboo joint shape along the length direction of the first pile body (10);
The first annular bulge (12) and the second annular bulge (13) are all in circular arrangement, the first thickening bulge (11) the first annular bulge (12) the second annular bulge (13) and the first pile body (10) are in coaxial arrangement, the first annular bulge (12) and/or the second annular bulge (13) comprises more than two arc-shaped bulges (120) which can be spliced with each other to form a circular ring shape, and the arc-shaped bulges (120) are fixed on the first pile body (10) in a welded or detachable mode.
8. A precast pile according to claim 7, characterized in that the inner peripheral wall of the arc-shaped protrusion (120) is provided with a groove (125), and when the arc-shaped protrusion (120) is fixed on the first thickening protrusion (11), the outer peripheral wall of the first thickening protrusion (11) and the inner side wall of the groove (125) are attached to each other so as to axially limit the arc-shaped protrusion (120).
9. The precast pile according to claim 7, characterized in that the arc-shaped protrusion (120) is formed by prefabricating concrete, at least one of two ends of the inner peripheral wall of the arc-shaped protrusion (120) along the length direction of the first pile body (10) is embedded with a first embedded steel member (121) extending along the circumferential direction, the first pile body (10) is embedded with a second embedded steel member (14) extending along the circumferential direction and corresponding to the first embedded steel member (121), and the first embedded steel member (121) is welded on the second embedded steel member (14) correspondingly.
10. The precast pile according to claim 9, wherein a plurality of first reinforcing bars (126), first connecting ribs (127) and radial ribs (128) are embedded in the arc-shaped protrusion (120), the plurality of first reinforcing bars (126) are uniformly arranged along the circumferential direction of the arc-shaped protrusion (120), the first reinforcing bars (126) extend along the axial direction of the arc-shaped protrusion (120), one ends of the two first connecting ribs (127) are respectively connected to two ends of the first reinforcing bars (126), the other ends of the two first connecting ribs (127) are respectively welded and fixed with the two first embedded steel pieces (121), the plurality of radial ribs (128) are connected to the first reinforcing bars (126) and uniformly distributed along the length direction of the first reinforcing bars (126), and the radial ribs (128) extend along the radial direction of the arc-shaped protrusion (120);
The utility model discloses a pile structure, including first pile body (10), second connecting bar (161) and second reinforcing bar, a plurality of second reinforcing bar (16) are followed circumference evenly distributed of first pile body (10) just is fixed in on prestressing force owner muscle (15) of first pile body (10), second reinforcing bar (16) correspond first thickening arch (11) set up, two one end of second connecting bar (161) connect respectively in one both ends of second reinforcing bar (16), two the other end of second connecting bar (161) respectively with two of first thickening arch (11) axial both sides second pre-buried steel piece (14) welded fastening.
11. A precast pile according to claim 7, characterized in that the arc-shaped protrusion (120) is precast by concrete, a through hole (129) extending along a radial direction is formed in the arc-shaped protrusion (120), the through hole (129) penetrates through an inner peripheral wall and an outer peripheral wall of the arc-shaped protrusion (120), a bolt hole (112) is formed in an outer peripheral wall of the first thickening protrusion (11), and an expansion bolt (17) penetrating through the through hole (129) is assembled in the bolt hole (112) to fix the arc-shaped protrusion (120) to the first thickening protrusion (11).
12. A precast pile according to claim 7, characterized in that the first annular protrusion (12) and/or the second annular protrusion (13) comprise a first conical surface (122 '), a cylindrical surface (123') and a second conical surface (124 ') which are sequentially connected from the first end (10') to the second end (10 ") of the first pile body (10), the cylindrical surface (123 ') extends along the length direction of the first pile body (10) and surrounds the outer side of the first pile body (10), the end of the first conical surface (122') facing the first end (10 ') is connected with the first pile body (10), the end of the second conical surface (124') facing the first end (10 ') is connected with the first pile body (10), and the second conical surface (124') cooperates with the first pile body (10) to form an annular concave cavity with an opening facing the second end (10").
13. A precast pile according to claim 5 or 7, wherein the first annular protrusion (12) and/or the second annular protrusion (13) each comprise a first conical surface (122), a cylindrical surface (123) and a second conical surface (124) which are sequentially connected from the first end (10 ') to the second end (10 ") of the first pile body (10), the cylindrical surface (123) extends along the length direction of the first pile body (10) and surrounds the outer side of the first pile body (10), the end of the first conical surface (122) towards the first end (10') is connected with the first pile body (10) at the end of the second conical surface (124) towards the second end (10"), the diameter of the first conical surface (122) gradually increases from the first end (10 ') to the second end (10 ") of the first pile body (10), and the diameter of the second conical surface (124) gradually decreases from the first end (10') to the second end (10") of the first pile body (10).
14. A precast pile according to claim 13, characterized in that the angle between the second conical surface (124) and the length direction of the first pile body (10) is more than 45 ° and less than 90 °.
15. A preformed pile according to claim 1, characterised in that the first pile body (10) is preformed integrally with the first thickening protrusion (11);
The outer peripheral wall of the end plate of the first end (10 ') is projected and surrounds the outer side of the first thickening protrusion (11) projected along the length direction of the first pile body (10), and the part of the end plate of the first end (10') extending out of the first pile body (10) forms the first annular protrusion (12).
16. A preformed pile according to claim 1, characterised in that the first pile body (10) is preformed integrally with the first thickening protrusion (11);
The utility model discloses a pile structure, including first annular protruding (12) and first pile body (10), first annular protruding (12) is end plate form setting, be equipped with a plurality of interval distribution's wears to establish hole (129') on the protruding (12) of first annular, wear to establish hole (129 ') and follow the length direction of first pile body (10) link up the both ends face of protruding (12) of first annular, be equipped with on the end plate of first pile body (10) first end (10') with wear to establish screw hole (19) that hole (129 ') corresponds, screw hole (19) are equipped with and pass wear to establish bolt (18) of hole (129') in order to with first annular protruding (12) are fixed in on first pile body (10).
17. A precast pile according to claim 16, characterized in that the threaded hole (19) is an anchoring hole of an end plate of the first end (10 ') of the first pile body (10) for passage of an upsetting head from the first end (10') to the second end (10 ").
18. A precast pile according to any one of claims 1 to 12 or 14 to 17, characterized in that the length of the first pile body (10) is defined as L, the first end (10') being the starting point, the first annular projection (12) being located within the [0, L/2] interval of the first pile body (10).
19. A precast pile according to claim 18, characterized in that the first annular projection (12) is located within the interval [0, l/4] of the first pile body (10).
20. A precast pile according to any one of claims 1 to 12 or 14 to 17, wherein the first thickening protrusion (11) and the first annular protrusion (12) are both parallel around the outer side of the first pile body (10), and the distance from the outer edge of the first thickening protrusion (11) projected in the length direction of the first pile body (10) to the outer edge of the first annular protrusion (12) projected in the length direction of the first pile body (10) is a fixed value, and the fixed value is not less than 40mm and not more than 150mm.
21. Precast pile according to any one of claims 1 to 5 or 7 to 12 or 14 to 17, characterized in that the first pile body (10) is arranged as a hollow circular pile, the first thickening protrusion (11) and the first annular protrusion (12) are arranged in a circular ring shape, the first thickening protrusion (11), the first annular protrusion (12) and the first pile body (10) are arranged coaxially, the outer diameter of the first annular protrusion (12) is 0 to 50mm larger than the diameter of the drilled hole, and the outer diameter of the first thickening protrusion (11) is 40 to 100mm smaller than the diameter of the drilled hole.
22. Precast pile according to any one of claims 1 to 5 or 7 to 12 or 14 to 17, characterized in that the first pile body (10) is arranged as a hollow circular pile, the first thickening protrusion (11) and the first annular protrusion (12) are arranged in a circular ring shape, the first thickening protrusion (11), the first annular protrusion (12) and the first pile body (10) are arranged coaxially, the outer diameter of the first pile body (10) is 350mm to 750mm, the outer diameter of the first annular protrusion (12) is 90mm to 200mm larger than the outer diameter of the first pile body (10), the outer diameter of the first thickening protrusion (11) is 50mm to 150mm larger than the outer diameter of the first pile body (10), and the outer diameter of the first annular protrusion (12) is 40mm to 150mm larger than the outer diameter of the first thickening protrusion (11).
23. A composite pile, comprising:
a top precast pile of precast piles (1) as defined in any one of claims 1 to 22, and
At least one bottom precast pile (2) connected to the lower end of the top precast pile;
The bottom precast pile (2) comprises a second pile body (20) extending vertically, and the projection of the outer peripheral wall of the second pile body (20) along the length direction of the first pile body (10) is completely overlapped with the projection of the outer peripheral wall of the first pile body (10) along the length direction of the first pile body (10).
24. The composite pile according to claim 23, wherein the bottom precast pile (2) further comprises a plurality of second thickening protrusions (21) circumferentially fixed on the outer peripheral wall of the second pile body (20), the second thickening protrusions (21) and the second pile body (20) are integrally precast, the plurality of second thickening protrusions (21) are arranged at intervals along the length direction of the second pile body (20), and the outer peripheral wall of the first annular protrusion (12) is projected around the outer side of the projection of the combination of the second pile body (20) and the second annular protrusion (21) along the length direction of the first pile body (10).
25. The composite pile according to claim 24, wherein the second pile body (20) and the first pile body (10) are all hollow round piles, the first thickening protrusions (11), the first annular protrusions (12) and the second thickening protrusions (21) are all circular, the first thickening protrusions (11), the first annular protrusions (12), the second thickening protrusions (21), the second pile body (20) and the first pile body (10) are coaxially arranged, a plurality of second thickening protrusions (21) are bamboo-shaped along the length direction of the second pile body (20), and the outer diameter of the second annular protrusions (21) is equal to the outer diameter of the first thickening protrusions (11).
26. A composite pile according to claim 25, characterized in that the bottom precast piles (2) are tubular structures having an inner cavity, and that at least one of the bottom precast piles (2) is fixed with a plugging structure at least partially plugging the inner cavity, or that at least one of the bottom precast piles (2) is of solid construction.
27. A composite pile according to claim 26, characterised in that the plugging structure is an end closure plate (3) provided at the end of the bottom precast pile (2).
28. A composite pile according to any one of claims 23 to 27, further comprising a constant cross-section pipe pile (4) connected to the upper end of the precast pile (1), the constant cross-section pipe pile (4) extending vertically and being integrally precast from concrete, the projection of the outer peripheral wall of the constant cross-section pipe pile (4) along the length direction of the first pile body (10) coinciding with the projection of the outer peripheral wall of the first annular projection (12) along the length direction of the first pile body (10).
29. The composite pile according to claim 28, characterized in that the first annular protrusion (12) is disposed at the uppermost end of the first pile body (10) and is connected with the constant-section pipe pile (4), the first annular protrusion (12) and the first pile body (10) are integrally preformed, the upper end face, the outer peripheral face and the lower end face of the first annular protrusion (12) are sequentially connected from top to bottom, the upper end face of the first annular protrusion (12) extends from the outer peripheral face to the first pile body (10), the upper end face of the first annular protrusion (12) is coplanar with the upper end face of the first pile body (10), the outer peripheral face of the first annular protrusion (12) extends vertically and surrounds the outer side of the first pile body (10), the lower end face of the first annular protrusion (12) extends from the outer peripheral face to the first pile body (10), the lower end face of the first annular protrusion (12) is in a conical surface, and the diameter of the first annular protrusion (12) gradually decreases from top to bottom.
30. A method of precast pile construction, wherein a precast pile as claimed in any one of claims 1 to 22 or a composite pile as claimed in any one of claims 23 to 29 is used.
31. A method of constructing a composite pile according to any one of claims 23 to 29, comprising the steps of:
S1, drilling, namely designing the drilling size according to the cross section size of a first pile body (10) of the precast pile (1), wherein the orthographic projection of the inner peripheral wall of the drilling on the horizontal plane surrounds the outer side of the orthographic projection of the combined body of the first pile body (10) and the first thickening protrusion (11) on the horizontal plane, and the orthographic projection of the inner peripheral wall of the drilling on the horizontal plane is completely covered by the orthographic projection of the second annular protrusion (12) on the horizontal plane;
s2, drilling construction, namely drilling according to drilling settings;
s3, planting and grouting the bottom precast piles (2), wherein the method comprises the steps of placing at least one bottom precast pile (2) into a drilled hole and injecting solidified slurry into the drilled hole;
S4, pile planting is carried out on the top precast pile, namely the precast pile (1) is arranged at the upper end of the bottom precast pile (2) at the uppermost end, and the precast pile (1) is pressed into a drilled hole, wherein the first annular bulge (12) and the second annular bulge (13) squeeze soil mass and/or solidified slurry on the surrounding wall of the drilled hole in the process of placing the precast pile (1) into the drilled hole.
32. A construction method according to claim 31, wherein the grouting is performed by injecting a volume of the cured slurry into the borehole, whereby the surface of the cured slurry is pressed into contact with the second annular protrusion (13) or the first annular protrusion (12) before the precast pile (1) is fully pressed into the borehole.
33. A construction method according to claim 31 or 32, wherein the length of the bottom 2.6m of the section of the bottom precast pile (2) initially introduced into the borehole has at least four second thickening protrusions (21) distributed.
34. The construction method according to claim 33, wherein step S2 further comprises performing an expanded-diameter borehole in the bottom of the borehole, the borehole cavity portion of the expanded-diameter borehole accommodating at least four second thickening protrusions (21) of the bottom of the section of bottom precast pile (2) that is first inserted into the borehole.
35. The construction method according to claim 34, wherein the depth of the expanded bore hole is greater than 2m and less than 3m, preferably greater than 2.4m and less than 2.8m.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202411451302.0A CN119640783A (en) | 2024-10-17 | 2024-10-17 | Prefabricated pile, combined pile and construction method |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202411451302.0A CN119640783A (en) | 2024-10-17 | 2024-10-17 | Prefabricated pile, combined pile and construction method |
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| CN119640783A true CN119640783A (en) | 2025-03-18 |
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| CN202411451302.0A Pending CN119640783A (en) | 2024-10-17 | 2024-10-17 | Prefabricated pile, combined pile and construction method |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN120739103A (en) * | 2025-08-29 | 2025-10-03 | 中国市政工程西北设计研究院有限公司 | Mechanical connection type precast pile for collapsible loess treatment |
| CN121087965A (en) * | 2025-11-10 | 2025-12-09 | 嘉兴欣创混凝土制品有限公司 | A type of precast pile that can prevent pile bursting during pile driving |
-
2024
- 2024-10-17 CN CN202411451302.0A patent/CN119640783A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN120739103A (en) * | 2025-08-29 | 2025-10-03 | 中国市政工程西北设计研究院有限公司 | Mechanical connection type precast pile for collapsible loess treatment |
| CN120739103B (en) * | 2025-08-29 | 2025-11-07 | 中国市政工程西北设计研究院有限公司 | Mechanical connection type precast pile for collapsible loess treatment |
| CN121087965A (en) * | 2025-11-10 | 2025-12-09 | 嘉兴欣创混凝土制品有限公司 | A type of precast pile that can prevent pile bursting during pile driving |
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