JP2007039955A - Ready-made pile and foundation pile structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily provide a foundation pile structure with high supporting force in which balance is kept between a vertical load, an extraction force, and a horizontal force. <P>SOLUTION: This ready-made pile 1 is formed by fitting a steel tube 15 to the upper part (intermediate part, upper part) of the annular projection 10A of a concrete part 3 having annular projections 10A, 10B at its lower end part 2. The lower end 16 of the steel tube 15 is locked to the step part 5 of the concrete part 3, and the outer surface of the steel tube 15 is formed flush with the outer surface of the small straight part 6 thereof. A pile hole 21 with an enlarged foot protection part 23 is excavated at the lower part of a shaft part 22, and the ready-made pile 1 is sunk into the pile hole 2. The lower ends 16 of the annular projections 10A, 10B are positioned in the enlarged foot protection part 23 to form the foundation pile structure 30 (a). A disk-like projection 20 may be formed at the lower end part of the steel tube 15 (b)(c). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a foundation pile utilizing the characteristics of SC pile and concrete pile, and a foundation pile structure in which this foundation pile is embedded in a pile hole.

(1) In the foundation pile structure in which the ready-made pile is buried in the pile hole, the length of one pile is about 10m, and the upper pile and the lower pile are generally joined to form the ready-made pile. It was. In this case, considering the horizontal load at the pile head, the upper pile has a large bending strength, for example, a so-called SC pile (concrete pile wound with a steel pipe), a so-called PRC pile (in parallel with a PC steel rod). Concrete piles with deformed reinforcing bars were used. Since these piles are generally expensive, a general concrete pile is used as a lower pile that does not require much bending strength.

(2) In addition, recently, a pile hole rooting part was built with specifications of specified quality and shape dimensions, and a concrete ready-made pile with embossed or the like at the lower end was buried in the pile hole, The foundation pile structure which positions the uneven part etc. was proposed. In the case of this foundation pile structure, it was possible to express a tip support force about twice as high as that in the case where a conventional pile made of concrete and a cylindrical pile without irregularities was used.

  In general, in the case of a joint pile in which a plurality of ready-made piles are connected vertically, the end plate (joint) needs to have the same diameter, so the outer diameter of the ready-made pile located in the pile-solidified portion of the pile hole and the root-solidified portion The outer diameter of the ready-made pile located further upward was the same diameter. In this case, when the outer diameter of the ready-made pile is designed on the basis of various proof stresses and strengths required for the root consolidation part, the outer diameter of the ready-made pile located above is the same as this, which is necessary. From the standpoint of the proof strength against vertical load and proof strength against horizontal load, there was a problem that the outer diameter was insufficient with the ready-made pile located above.

(3) In order to solve such problems, the inventors have already changed the outer diameter in the middle of the concrete pile, the lower end is a small diameter, the outer diameter adjustment part, the upper part is a large diameter A pile is proposed (Patent Document 1). In this invention, the outer diameter adjustment part of the ready-made pile is located in the root consolidation part, the small-diameter ready-made pile part is located in the root consolidation part, and the large-diameter part of the ready-made pile is located above the root consolidation part. As a result, it was possible to satisfy the vertical strength (compressive strength) over the entire length of the ready-made piles and to secure the vertical support force. And the foundation pile structure has been recognized in the market.

Also, using a concrete pile as a base, and using a foundation pile formed with unevenness using steel, the foundation pile is embedded in the pile hole, and the unevenness using steel is positioned at the root of the pile hole. And the invention which comprises a foundation pile structure is also proposed (patent document 2).
JP 2002-97635 JP2000-45274

(1) In the case of cited document 1 among the said prior arts, for example, when a so-called SC pile (concrete pile covered with a steel pipe) is used for a ready-made pile (upper pile) used in the upper part of the ready-made pile. It was possible to secure high vertical strength, horizontal strength, and tensile strength at the SC pile portion. In this case, since the ready-made pile located in the root consolidation part uses a concrete pile, when further increasing the supporting force exerted in the root consolidation part of the pile hole, the outer diameter of the concrete pile located in the root consolidation part is increased. It was necessary to increase the vertical proof stress by doing (thickening the pile wall thickness). However, there is a limit to the method of increasing the vertical bearing capacity by increasing the outer diameter of the concrete piles, and it may be impossible to cope with higher bearing capacity.

  Moreover, when the lower pile is a ready-made pile made of concrete, since the pulling strength is small, the foundation pile structure has a poor balance with the upper pile having a high pulling strength.

  Therefore, it was necessary to enhance the vertical and pulling strength of the lower pile used by burying the lower end of the pile in the rooting portion.

(2) Moreover, in the case of the cited reference 2, it was implement | achieving strengthening the vertical strength of a pile material itself, and a drawing strength using the steel pipe pile etc. which used steel materials as a lower pile. However, the processing of the complicated uneven shape of steel materials is required, and high technical power is required for this processing, and it was difficult to manufacture easily. Therefore, high-strength lower piles that can withstand high bearing capacity cannot be manufactured and supplied stably, and because many steel materials are used, the cost of piles for ready-made piles is too high, which reduces costs. There were also problems that were difficult and inferior in versatility.

  Therefore, the realization of a foundation pile structure that satisfies the vertical strength, horizontal strength, and pullout strength in a well-balanced manner and has good economic efficiency has been an issue.

  Since the horizontal force acting on the ready-made piles is borne by the steel pipe and the structure of the solidified part can be dealt with by the protrusion made of concrete, the above-mentioned problems have been solved.

  That is, in the present invention, the lower end portion of the concrete pile main body is formed with a predetermined shaft diameter, the irregular uneven portion is formed on the lower end portion, and at least the whole or a part of the upper portion of the pile main body is a steel pipe having a length L. It is a ready-made pile characterized by covering.

  Moreover, in the above, it is a ready-made pile characterized by forming the outer diameter of the part which is not covering the steel pipe in the pile main body, and the outer diameter of the part covering the steel pipe with different diameters. Moreover, in the above, it is the ready-made pile which is embedded and used in the pile hole which has a root consolidation part, Comprising: It is the ready-made pile comprised so that the lower end part of the said existing pile may be located in the root consolidation part of the said pile hole. Moreover, it is a ready-made pile which is embedded and used in a pile hole having one or more strength enhancing portions in the depth direction, and the steel pipe is placed so that the lower end of the steel pipe is located in the strength enhancing portion of the pile hole. It is a prefabricated pile.

  Another invention is a ready-made pile formed by vertically joining a plurality of unit piles having a predetermined shaft diameter, and at least one unit pile is configured by covering all or part of the outer periphery with a steel pipe. And at least 1 unit pile is a ready-made pile characterized by forming the irregular uneven | corrugated | grooved part in all or one part of outer periphery. Moreover, in the said, it is the ready-made pile characterized by forming the shaft diameter of the unit pile located up and down with a different diameter.

  Moreover, in the foundation pile structure which embeds and constructs a ready-made pile in the pile hole which has a root-solidification part, the said ready-made pile comprises a plurality of unit piles which have a predetermined axis diameter, and constitutes, Among them, at least one unit pile is constructed by covering all or part of the outer periphery with a steel pipe, and at least one unit pile is constructed by forming irregular irregularities, It is.

  Further, in the above, the foundation pile structure is characterized in that at least one irregularly shaped uneven portion is positioned in a rooted portion of the pile hole. Further, in the above, a pile circumference fixing liquid layer is formed between the pile hole and the ready-made pile, a strength increasing portion is formed at a predetermined depth of the pile circumference fixing liquid layer, and upper ends of one or a plurality of steel pipes Or it is the foundation pile structure characterized by having embed | buried a part or all of each position of a lower end position, the joint position of a unit pile, and a deformed uneven | corrugated | grooved part position in the said strength enhancement part.

  Furthermore, in the foundation pile structure which embeds and constructs a ready-made pile in a pile hole which has a root consolidation part, a pile circumference fixed liquid layer is formed between a pile hole and a ready-made pile, and the predetermined circumference of this pile circumference fixed liquid layer is formed. A strength increasing portion is formed at a depth, and the ready-made pile covers at least an upper part of a concrete pile main body with a steel pipe having a length L and is close to the upper end or the lower end of the steel pipe with the concrete pile main body. Then, the irregular pile portion is formed, and the irregular pile portion and the upper end or the lower end of the steel pipe are embedded in the root hardening portion or the strength enhancing portion.

  The “irregular irregularities” in the above refers to concave portions or convex portions or a combination of concave portions and convex portions different from the surrounding surface shape. Furthermore, a step having a changed diameter is also included. In short, it is only necessary to form a downward surface in order to increase the vertical support force and to form an upward surface in order to increase the pulling force.

  The “strength enhancing portion” in the above is a solidified portion formed in the pile hole at a depth corresponding to the support ground that mainly exhibits the tip support force. In the root consolidation part, the cemented milk of a rich blend is filled and solidified as compared with the pile hole shaft part to form a root consolidation layer. In this case, it is desirable that the root consolidation portion is expanded and excavated from the pile hole shaft portion to form an enlarged root consolidation portion, but it may be the same diameter as the pile hole shaft portion.

  In addition, the “strengthening part” is abundant in the pile hole compared to the shaft part of the pile hole, corresponding to the intermediate support layer, in the ground where the intermediate support layer is shallower than the depth to the ground where the tip support force is exhibited. The blended cement milk can be filled and solidified to form a “strength enhancing portion”. In this case, it is possible to fill and solidify the rich blended cement milk, and further to make the pile hole diameter at that depth larger than the surrounding diameter. Further, it is desirable that the cement milk is rich, but if the pile hole diameter at the depth is made larger than the surrounding diameter, the cement milk can be mixed with the surrounding pile fixing liquid.

  If the irregularities are formed at the lower end of the pile body and the irregularities are located in the rooting part, the bottom surface in the rooting part or the top surface toward the ground can be formed, so it has solidified The function of the root hardening liquid layer can be fully exhibited, and the vertical load or pulling force acting on the ready-made pile can be effectively borne. Furthermore, since the upper part of the ready-made pile is covered with the steel pipe, even when a large horizontal force is applied to the ready-made pile, the ready-made pile part whose upper part is covered with the steel pipe can be sufficiently handled.

  Therefore, a well-balanced foundation pile structure with a good balance can be realized, and the conventional pile foundation with the small number or small diameter can be achieved.

  Moreover, since it is a deformed uneven part made of concrete, it has good compatibility with the root-setting liquid in the root-solidified part, and power can be efficiently transmitted from the irregular-shaped uneven part made of concrete into the solidified root-setting liquid layer.

  In addition, when a protrusion is formed at the lower end of the steel pipe, the pulling force can be borne only by the steel pipe part at the upper part of the pre-made pile, and the influence of the pulling force is reduced at the concrete part at the lower part of the pre-made pile. The concrete part can be made into a simple form. Further, since the pulling strength of the ready-made pile itself can be increased, a balanced high strength foundation pile structure such as a supporting force, a horizontal force, and a pulling force becomes possible.

  In addition, when a protrusion is formed on the lower end of the steel pipe and the lower end of the steel pipe is positioned in the root consolidation part of the pile hole, the concrete part at the lower end of the pre-made pile is completely embedded in the root consolidation part, and the concrete part Will be reinforced by the solidified root hardening liquid, and the strength of the concrete will be greatly improved. Therefore, a well-balanced high strength foundation pile structure can be realized by the ready-made pile structure that can sufficiently exhibit the performance of the upper steel pipe portion.

(1) ready-made pile of the present invention forms a lower portion of the concrete pile body with an outer diameter D _0, formed by an outer diameter D ₁ of the non-lower end (upper, middle section) (D ₁ ≦ D ₀ ). The portion of the outer diameter D ₀ to form an annular projection (irregular uneven portion). Annular projection is constructed adjacent to the stepped portion of the outer diameter D ₀ (the portion size is changed). Outer diameter D ₁ of the portion of the pile body, there by a length L _5, and covers the steel pipe having an outer diameter D in length L ₅ in that portion, constituting a prefabricated pile of the present invention. Position of the outer diameter D ₁ of the portion of the, i.e. the portion covered steel pipes, since generally sought to strengthen the lateral strength, but that are placed outside the lower end of the pile body, arranged at the lower end portion of the pile body You can also

(2) (1), an outer diameter _{D 0} of the pile body, an outer diameter _{D 1} of the portion coated with _steel, as D 1 _{<D 0,} if the outer diameter D = _{D 0} of the steel pipe, the steel pipe The outer diameter and the outer diameter of the lower end of the pile main body can be made the same, and a step can be eliminated on the surface. In this case, since the same diameter is formed in the length direction of the pile except for the irregular concavo-convex portion, there is little resistance at the time of embedding, and there is little possibility of stress concentration at the diameter changing portion after embedding.

However, it is also possible to form a step on the outer circumference of the lower end outer periphery and the steel pipe pile body (concrete portions) as D ≠ D _0. Moreover, the pile main body (concrete part) is set to D ₁ = D ₀ , the diameter of the pile main body is the same diameter in the upper and lower sides, and without forming a step in the pile main body, the outer periphery of the lower end of the pile main body and the outer periphery of the steel pipe A step can also be formed.

(3) It is desirable to install the lower end portion of the ready-made pile, that is, the irregular concavo-convex portion so as to be positioned in the root-solidified portion. A root hardening layer is formed in the root hardening part to be solidified by filling cement milk with a rich blend. By positioning the irregularities in the root consolidation layer, the vertical load acting on the ready-made pile can be efficiently transmitted to the root consolidation layer, and a greater bearing force can be exhibited. In other words, when a vertical load is applied to the ready-made pile, the load is distributed to the bottom surface of the rooting layer in a distributed manner from the surface facing the lower side of the irregular concavo-convex portion to the lower side.

  Therefore, it is preferable that the irregular irregularities are located in the enlarged root consolidation part. However, in the ground where the support layer is located in the middle, the strength enhancement part (equivalent to or slightly equal to the root consolidation part) is formed at a depth near the intermediate support layer of the pile hole. It is also possible to form cemented milk of a composition that falls in strength, the diameter of which is the same as or larger than that of the pile hole shaft, and to place the irregular irregularities in the intermediate support layer.

  Further, the upward-facing surface formed on the irregular concavo-convex portion similarly acts on the pulling force.

(4) Although the annular projection is formed as the irregular irregular portion, it can be an intermittent projection, and a recess or groove can be formed in the lower end shaft portion. In short, a portion having a diameter different from that of the lower end shaft portion of the lower end portion shaft portion that protrudes or is recessed is formed, whereby a surface directed downward (for vertical load support), a surface directed upward ( It is only necessary that a pulling force support) is formed.

(5) the length L ₅ of the steel tube, the lower end of the steel pipe so as to position the root compaction portion of Kuiana, it is desirable to set. The root-solidified portion is filled with a rich blend of cement milk and solidified to form a root-solidified layer. Since the stress tends to concentrate at the lower end of the steel pipe, it is ensured that the vertical load is applied from the ready-made pile to the consolidation layer without being affected by stress concentration (especially bending stress) by being located in the consolidation layer. Can communicate.

  Moreover, when the strength increasing portion is formed at a depth near the intermediate supporting layer of the pile hole in the ground where the supporting layer is located in the middle, the lower end of the steel pipe can be positioned in the strength increasing portion.

(6) Although a ready-made pile comprises the invention of said (1) from one ready-made pile, a several unit ready-made pile can also be connected up and down and formed. In this case, the shaft diameter of the unit piles positioned above and below can be formed with different diameters, depending on the function of the ready-made piles required at each depth by selecting the presence or absence of annular protrusions, presence or absence of coating of steel pipes, etc. Select and configure a well-balanced foundation pile structure.

  In short, when constructing ready-made piles by connecting multiple single piles up and down, depending on the ground, a strength enhancing part is formed in one or more places in the pile hole, so this strength enhancing part Correspondingly, a steel pipe may be attached, or a deformed uneven portion may be formed. Depending on the arrangement of the strength-enhancing part, steel pipes may be formed on all single piles, or irregular irregularities may be formed.

(7) In (1), since the steel pipe mainly acts on bending stress and shear stress, it is sufficient to cover at least the upper end portion, and the intermediate portion and the lower end portion are intermittent as required. It is also possible to coat with a plurality of steel pipes.

(8) as in (1), although the outer diameter of the lower end shaft diameter _{D 0} and the steel pipe was the same as _{D 0} (FIG. 3 (b)),
It can be formed with different diameters, such as the outer diameter of the coated steel pipe <the shaft diameter of the lower end of the pile body. Since the lower end of the pile body is not covered with a steel pipe, it is generally desirable to have a larger diameter than the steel pipe, but on the contrary,
The shaft diameter of the lower end of the pile body may be smaller than the outer diameter of the coated steel pipe.

(9) The foundation pile structure is constructed by burying the ready-made pile constructed as described above in a pile hole excavated in advance (or in the pile hole while excavating the pile hole). In the case where a root consolidation part (strength enhancement part) is formed at the tip of the pile hole, the annular projections (deformed irregularities) of the ready-made pile and the lower end of the steel pipe are positioned in the root consolidation part of the pile hole.

  Moreover, the shaft part (upper part or intermediate part) of the pile hole is filled with a pile fixing liquid (generally cement milk that is poorer than the root hardening liquid). In a certain ground, it is possible to make the strength enhancing part as a composition corresponding to the intermediate support layer, in which the cement milk is dropped to the same degree or slightly as the root hardening layer.

  In addition, when a plurality of irregularly shaped irregularities are formed, it is desirable that all of them be located in the rooting part or other strength enhancing part, but the object can be achieved if at least one irregularly irregular part is located.

  Further, the upper end or the lower end of the steel pipe, that is, the joint portion of the steel pipe and the concrete on the surface of the ready-made pile is generally likely to be stress concentrated, so it is desirable that the steel pipe and the concrete joint be positioned at the root hardening part or other strength enhancing part.

  Embodiments of the present invention will be described with reference to the drawings.

[1] Configuration of ready-made pile 1

(1) A steel pipe 11 having a length L ₅ and an outer diameter D ₀ is installed in a mold (not shown) having a recess for forming the annular protrusions 10 and 10, and necessary PC steel bars and reinforcing bars are attached. It arrange | positions, casts concrete, and centrifugally forms, and the ready-made pile 1 of this invention is comprised (FIG. 1 (a)).

(2) This ready-made pile 1 has a steel pipe 15 fitted above (intermediate part, upper part) above the annular protrusion (upper side) 10A of the concrete part 3 having the annular protrusions (deformed irregularities) 10A, 10B at the lower end part 2. It has a structure. The concrete part 3 includes a straight part 4 to which the steel pipe 15 is attached, a step part 5 to which the lower end 16 of the steel pipe 15 is locked, a small straight part 6 between the step part 5 and the annular protrusion 10A, and between the annular protrusions 10A and 10B. The small straight portion 7 is composed of a small straight portion 8 below the annular protrusion 10B.

  The lower end 16 of the steel pipe 15 is engaged with the step part 5 of the concrete part 3, and the outer surface of the steel pipe 15 and the outer surface of the small straight part 6 are formed flush with each other.

(3) annular projection 10 has an annular projection 10A, two of 10B, the position of _H 1, _{H 2} from the lower end 2a, the length of the radial (length of exit) at _{L 1,} it is formed. Further, the annular protrusion is formed in a tapered shape at the top and bottom, and has an inclined upper surface 11 and an inclined lower surface 12, respectively.

(4) In the figure, reference numerals 18 and 19 denote upper and lower end plates, respectively.

(5) Also, for example,
Steel pipe outer diameter D ₀ = 60 cm
The outer diameter of the annular protrusion “D ₀ + 2 × L ₁ ” = 75 cm
The height H ₂ of the annular protrusion 10A = 150 cm
Height H ₁ = 50 cm of noble annular protrusion 10B
Distance between annular protrusions “H ₂ −H ₁ ” = 100 cm
It is formed with.

[2] Configuration of foundation pile structure 30

(1) Excavate a predetermined pile hole 21 formed with the enlarged rooting portion 23 below the shaft portion 22 (FIG. 1A).

(2) The ready-made pile 1 is set in the pile hole 21, and the two annular protrusions 10 </ b> A and 10 </ b> B and the lower end 16 of the steel pipe 15 (the stepped portion 5 of the concrete portion 2) are located in the enlarged rooting portion 23. Install in. At this time, the root consolidation liquid 23 is filled in the enlarged root consolidation part 23 of the pile hole 21, and the shaft periphery 22 of the pile hole 21 is filled with the pile circumference fixing liquid. If the root hardening liquid and the pile periphery fixing liquid are solidified, the foundation pile structure 30 of the present invention is configured. The foundation pile structure 30 includes the annular projections 10A and 10B of the ready-made pile 1 and the bottom end of the steel pipe 15 (in the vicinity of the stepped portion 5) in the rooting layer 25 where the rooting liquid is solidified, and the steel pipe 15 of the ready-made pile 1 is The fixed liquid is embedded in the pile peripheral fixed liquid layer 26 that has solidified.

(3) The root-setting liquid of the root-setting liquid layer 26 is formed by stirring and mixing concrete, mortar, cement milk, or drilling mud and cement milk that has been replaced with the drilling mud.

  In addition, after the solidified liquid layer 26 is solidified, when a vertical load is applied to the ready-made pile 1, shear force propagates from the inclined lower surfaces 12 and 12 of the annular protrusions 10 </ b> A and 10 </ b> B and / or the bottom 2 a of the ready-made pile 1. Thus, a larger load can be borne until the root-solidifying liquid layer 26 is broken (until a crack is generated along the propagation direction of the shearing force). The root hardening liquid which comprises the root hardening liquid layer 26 is adjusted so that it may become the solidification intensity | strength of the grade which enables such an effect | action. Usually, the solidification strength of the root hardening liquid of the root hardening liquid layer 26 is substantially the same as the ground strength of the supporting ground.

(4) Further, when a pulling force is applied to the foundation pile 1 of the foundation pile structure 30, the inclined projections 11 </ b> A and 10 </ b> B in the root hardening liquid layer 26 are inclined upward from the inclined upper surfaces 11 and 11 in the same manner as the vertical load. Thus, more pulling force can be borne until the shearing force propagates and the root hardening liquid layer 26 is destroyed.

(5) Moreover, when a horizontal load acts on the pile head of the ready-made pile 1 of the foundation pile structure 30 at the time of an earthquake etc., since the outer periphery of the concrete part 3 is covered with the steel pipe 15 in the ready-made pile 1, this Can be fully paid. At this time, the portion not covering the steel pipe 15, that is, the portion below the lower end 16 of the steel pipe 15, is located in the root hardening liquid layer 26 and is covered with the solidified root hardening liquid. The foundation pile structure 30 has a sufficient horizontal resistance as a whole.

[3] Other embodiments

(1) In the above embodiment, two annular protrusions are formed, but it is possible if at least one is formed. Further, when two or more annular protrusions are formed, it is necessary to effectively propagate the shearing force in the root hardening liquid layer. Therefore, the interval between the annular protrusions (H ₂ −H ₁ ) is the lower surface 12 of each annular protrusion 10, 10. , 12 and a length that prevents the propagation of shear forces from the upper surface 11 of the annular protrusions 10 and 10 obliquely upward.

(2) In the said Example, the disk-shaped protrusions 20 and 20 can be formed in the lower end part of the steel pipe 15, and it can also be set as the foundation pile structure 30 (FIG.2 (b) (c)). Disk-shaped protrusion 20 is welded to the lower end 16 of the steel pipe 15 (FIG. 2 (b)), or may be welded upward at a distance _{L 2} from the lower end 16 (FIG. 2 (c)).

  In this case, when the ready-made pile 1 is subjected to centrifugal molding, a donut-shaped steel plate (or two donut-shaped steel plates in half) can be welded to the steel pipe 15 in advance, or after centrifugal molding, A donut-shaped steel plate can be formed at a predetermined position of the steel pipe 15 by welding.

  In any case, the disk-like protrusion 20 is embedded in the ready-made pile 1 so as to be located in the root hardening liquid layer 26 of the pile hole 21 to constitute the foundation pile structure 30 and is the same as the annular protrusions 10A and 10B. The function is exhibited (FIGS. 1B and 1C).

(3) Moreover, in the said Example, although the level | step-difference part 5 was formed in the concrete part 3 and the steel pipe 15 surface and the surface of the small straight part 6 were formed in the same plane, the level | step-difference part 5 was abbreviate | omitted and straightened. The part 4 and the small straight part 6 can also be formed continuously (not shown).

(4) Moreover, in the said Example, although the ready-made pile 1 was used independently, it connects with the normal SC pile as an upper pile, using the ready-made pile 1 as a lower pile, and embed | buried in the pile hole 21, and a foundation It can also be set as the pile structure 30 (not shown).

  In the said Example 1, although the ready-made pile 1 was made into the single pile, in this Example, an up-and-down pile is connected and the ready-made pile 1 is comprised.

[1] Configuration of ready-made pile 1

(1) The ready-made pile 1 of this embodiment is configured by joining an upper pile 32 and a lower pile 33 with a connecting joint 34 (FIG. 3B).

(2) The upper pile 32 covers the periphery of the concrete base 3 (outer diameter D ₁ ) with a steel pipe 15 (length L ₅ , outer diameter D ₀ , inner diameter D ₁ ), and steel end plates 18 on the upper and lower sides. This is a so-called SC pile constructed by installing 41. A fitting groove 43 for joining is formed on the outer periphery of the lower end plate 41. The upper pile 32 is formed with a length L ₄ and an outer diameter D ₀ .

(3) lower pile 33, concrete pile length _{L 3,} 2 one annular protrusion 10A on the outer periphery, Yes to form 10B, the upper end plate 42 up and down, is attached to the lower end plate 19. Similar to the first embodiment, two annular protrusions 10A and 10B are formed at radial positions (out) L ₁ at positions H ₁ and H ₂ from the lower end 33a. A fitting groove 43 is formed on the outer periphery of the upper end plate 42.

  The upper pile 33 has a small straight portion 6 between the upper end plate 42 and the annular protrusion 10A, a small straight portion 7 between the annular protrusions 10A and 10B, and a small straight portion 8 below the annular protrusion 10B.

(4) The coupling joint 34 is configured by projecting a disk-like protrusion 36 on the outer surface of the joint body 35 having an inner surface that can be in close contact with the outer peripheral surfaces (the lower end plate 41 and the upper end plate 42) of the upper pile 32 and the lower pile 33. . On the inner surface of the coupling joint 34, fitting protrusions 37, 37 that can be fitted to the fitting grooves 43, 43 in a state where the upper and lower piles 32, 33 are overlapped are formed.

  The connecting joint 34 is composed of three joint pieces 34a and 34a divided in the circumferential direction. Accordingly, the joint body 35 is constituted by three joint body pieces 35a and 35a, and the disk-like protrusion 36 is constituted by three disk-like protrusion pieces 36a and 36a, respectively.

(5) The upper pile 32 is overlaid on the lower pile 33, the coupling joint pieces 34a and 34a are fitted into the overlapped portions, and the fitting protrusions 37 and 37 of the joint body pieces 35a and 35a are fitted into the fitting grooves 43 and 43, respectively. Install while inserting. Each joint piece 34a, 34a and the upper pile 32, each joint piece 34a, 34a and the lower pile 33 are welded, and if necessary, the overlapped joint pieces 34a, 34a are welded together and connected. Then, the upper and lower piles 32, 33 are joined together via the connecting joint pieces 34a, 34a. The ready-made pile 1 of this invention is comprised as mentioned above (FIG. 2 (a) (b)).

(6) In this embodiment, by preparing a lower pile 32, by combining the SC piles of any length L _4, it is possible to configure the ready-made pile 1 of the present invention, soil conditions of the construction site to be used Depending on the situation, it is easy to deal with.

[2] Configuration of foundation pile structure 30

(1) As in the first embodiment, a predetermined pile hole 21 formed in the enlarged rooted portion 23 is excavated below the shaft portion 22, and the ready-made pile 1 is set in the pile hole 21 (FIG. 3A). ).

  The lower pile 33 including the two annular protrusions 10 </ b> A and 10 </ b> B, the coupling joint 34, and the lower ends of the upper pile 32 are located in the enlarged root consolidation portion 23 of the pile hole 21, and the root solidification liquid in the enlarged root consolidation portion 23. Is embedded in the root-solidified liquid layer after the solidification. Moreover, the intermediate part and upper part of the upper pile 32 are located in the axial part 22 of the pile hole 21 filled with the pile periphery fixing liquid, and are embed | buried in a pile periphery fixed liquid layer, and comprise the foundation pile structure 30 (FIG. 3 (a)).

(3) The effects of vertical load, pull-out force, and horizontal force acting on the foundation pile 1 are the same as those of the first embodiment (especially the first embodiment shown in FIGS. 1A and 1B and FIGS. 2A and 2B). ).

(4) The upper pile 32 and the lower pile 33 can be connected at the construction site, or can be connected in advance at the factory.

[3] Other embodiments

(1) In the said Example, although the coupling joint which has the disk shaped protrusion 36 was used, the normal coupling joint which does not have a disk shaped protrusion can also be used. In this case, a conventional non-welded coupling joint can also be used (none is shown). Moreover, the upper and lower piles 32 and 33 can also be joined only by welding, without using a coupling joint (not shown).

(2) Other embodiments are the same as those in the first embodiment.

(A)-(c) is a front view of the foundation pile structure of the Example of this invention. (A)-(c) is the ready-made pile of the Example of this invention, and is a longitudinal cross-sectional view corresponding to the foundation pile structure of FIG. In another embodiment of the present invention, (a) is a front view of a foundation pile structure, and (b) is a longitudinal sectional view of a ready-made pile. It is the A section enlarged view of Drawing 3 (b), (a) expresses before joining and (b) expresses after joining, respectively. It is BB sectional drawing of FIG.3 (b).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ready-made pile 2 Lower end part of ready-made pile 3 Concrete part 5 of ready-made pile Step part 10, 10A, 10B of a concrete part Annular projection (deformed uneven part)
11 Inclined upper surface of annular projection 12 Inclined lower surface of annular projection 15 Steel pipe 16 Lower end 18 of steel pipe End plate (upper)
19 End plate (bottom)
20 Disk-like projection 21 Pile hole 22 Pile hole shaft part 23 Pile hole bottom part 24 Pile hole rooting part 25 Root consolidation liquid layer 26 Pile circumference fixed liquid layer 30 Pile structure 32 Upper pile 33 Lower pile 34 Connecting joint 35 Joint body 36 of the coupling joint Disc-shaped projection 37 of the coupling joint Mating projection 41 of the coupling joint Upper end plate 42 of the upper pile Upper end plate 43 of the lower pile End plate fitting groove

Claims (10)

The lower end portion of the concrete pile body is formed with a predetermined shaft diameter, the irregular uneven portion is formed at the lower end portion, and at least the upper part of the pile body is covered with a steel pipe having a length L. Ready-made piles. The ready-made pile according to claim 1, wherein an outer diameter of a portion of the pile body that does not cover the steel pipe and an outer diameter of the portion that covers the steel pipe are formed with different diameters. It is a ready-made pile which is embedded and used in a pile hole having a root-solidified portion, and is configured such that a lower end portion of the pre-made pile is located at a root-solidified portion of the pile hole. Ready-made pile as described. It is a ready-made pile that is used by being embedded in a pile hole having one or more strength enhancing portions in the depth direction, and the steel pipe is configured so that the lower end of the steel pipe is located in the strength enhancing portion of the pile hole. The ready-made pile of any one of Claims 1-3 characterized by the above-mentioned. It is a ready-made pile formed by joining a plurality of unit piles having a predetermined shaft diameter up and down,
At least one unit pile is configured by covering all or part of the outer periphery with a steel pipe, and at least one unit pile is configured by forming irregular irregularities on all or part of the outer periphery. Ready-made piles. The ready-made pile according to claim 5, wherein the shaft diameters of unit piles positioned above and below are formed with different diameters. In a foundation pile structure configured by burying a ready-made pile in a pile hole having a root consolidation part, the ready-made pile is configured by vertically joining a plurality of unit piles having a predetermined shaft diameter, A basic pile structure characterized in that at least one unit pile is configured by covering all or a part of the outer periphery with a steel pipe, and at least one unit pile is formed by forming irregular irregularities. The foundation pile structure according to claim 7, wherein at least one irregularly shaped uneven portion is positioned in a rooted portion of the pile hole. A pile circumference fixed liquid layer is formed between the pile hole and the ready-made pile, a strength increasing portion is formed at a predetermined depth of the pile circumference fixed liquid layer, and an upper end or lower end position of one or a plurality of steel pipes, a unit The foundation pile structure according to claim 7, wherein a part or all of each position of the joint position of the pile and the irregular uneven part position is embedded in the strength increasing part. In the foundation pile structure constructed by burying the ready-made pile in the pile hole having the root consolidation part, a pile circumferential fixed liquid layer is formed between the pile hole and the ready-made pile, and the predetermined depth of the pile circumferential fixed liquid layer Forming a strength increasing portion, and the ready-made pile covers at least an upper part of a concrete pile main body with a steel pipe having a length L, and is close to the upper end or the lower end of the steel pipe in the concrete pile main body. A foundation pile structure characterized by forming irregular irregularities, and embedding the irregular irregularities and the upper end or lower end of the steel pipe in the root hardening portion or the strength increasing portion.

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