CN115748674A

CN115748674A - Leak protection anti-floating pile

Info

Publication number: CN115748674A
Application number: CN202211597162.9A
Authority: CN
Inventors: 徐旭; 赖洁伟; 王�琦; 孔维涛; 王改革; 刘乐乐; 蒋鹏
Original assignee: Third Construction Co Ltd of China Construction Eighth Engineering Divison Co Ltd
Current assignee: Third Construction Co Ltd of China Construction Eighth Engineering Divison Co Ltd
Priority date: 2022-12-12
Filing date: 2022-12-12
Publication date: 2023-03-07
Anticipated expiration: 2042-12-12
Also published as: CN115748674B

Abstract

The invention relates to a leakage-proof uplift pile, which comprises a pile body and a pile head, wherein the lower end of the pile body is provided with a bottom plate, the bottom surface of the bottom plate is a first spherical surface, the lower surface of the bottom plate is provided with a boss matched with the pile head, the bottom surface of the boss is a second spherical surface, and the pile head is formed by assembling a plurality of subshells with the same structure and size; the edge of the upper end of the sub-shell, which is matched with the first spherical surface, is a third spherical surface; the first spherical surface, the second spherical surface and the third spherical surface and a pile tip point of the pile head are spherical centers; the second spherical surface is provided with sliding grooves corresponding to the sub-shells one to one, the inner wall surfaces of the sub-shells are fixedly provided with sub-covers, guide rods are fixedly arranged above the sub-covers, the top ends of the guide rods are in sliding fit with the sliding grooves through sliding blocks, the sub-shells are forced to only execute rotary motion with pile tip points as pivot points through spherical surface fit, the sliding grooves and the guide rod structures, and concrete is prevented from leaking when the pile heads are not expanded in place.

Description

Leak protection anti-floating pile

Technical Field

The invention belongs to the field of constructional engineering, and particularly relates to a leakage-proof uplift pile.

Background

The uplift pile is widely applied to uplift of large basements, uplift of high-rise buildings, uplift of offshore wharf platforms, anchor pile foundations of suspension bridges and cable-stayed bridges, pile foundations of large ship dock floors, anchor pile foundations in static load test piles and the like. When one part of the underground structure of the building engineering is lower than the water level of the surrounding soil, uplift piles are required to be arranged to offset the uplift force generated by water in the soil on the structure, so that the stability of the building structure is ensured.

The existing uplift pile is mainly manufactured in a cast-in-place mode, the construction process is complex, and the construction efficiency is extremely low; moreover, due to different geological conditions of different construction regions, the soil layer collapse phenomenon in the punching process is difficult to control; in addition, when the traditional uplift pile construction method of the whole pile cast-in-place is adopted, the poured concrete is easily mixed and diluted by mud water in the hole, so that the strength of the whole pile is difficult to ensure. In view of the above drawbacks, although a novel uplift pile is discussed in the prior art (CN 112227359B), the uplift pile can utilize grouting pressure to expand the pile head from the upper portion, so as to form an enlarged head and a cemented stone body at the pile bottom, the enlarged head portion of the uplift pile has no gap, and does not depend on the floating process of the pile body to form the enlarged head, so that the structure is stable and reliable.

However, the pile head in the prior art has high limiting conditions for the pile foundation soil layer structure and the grouting pressure, and when the pile head is applied to a soft soil layer or a scene with an excessive soil layer water content, because the soil layer has a low supporting force for the pile head, a pile separation phenomenon (as shown in fig. 13) occurs in which the pile head is separated from the tail end of the pile body and moves downwards in the grouting process, so that concrete leaks from the upper end of the pile head, and an enlarged head cannot be effectively formed; when the grouting pressure is applied to a hard soil layer, the grouting pressure needs to be increased to expand the pile head, but since concrete slurry directly impacts the lower part of the pile head, when the grouting pressure is too high, the lower end of the pile head expands before the upper end (namely, a rotary expansion process around a pivot point B as shown in FIG. 14 occurs), so that concrete leaks from the lower end of the pile head, and the expanded head cannot be formed effectively.

In addition, in this prior art, the surface of the upper end of the pile head and the lower surface of the boss both adopt a planar structure, and this planar contact mode can form a good closed space when the pile head is not expanded, but after the pile head is expanded to a certain extent (expanded according to its design mode), the arc-shaped inner edge of the upper end of the pile head sub-shell is in turn in contact with the lower surface of the boss, and the structure of matching the plane and the arc-shaped edge inevitably forms a gap on the upper end of the pile head sub-shell, resulting in the concrete slurry to be leaked in advance.

Therefore, the present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a leakage-proof and uplift pile which can be adapted to all types of soil structures, has a wide grouting pressure limit condition, and can prevent concrete grout from leaking prematurely from the top or bottom of a pile head.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a leakage-proof uplift pile which can prevent concrete grout from leaking from a pile head at the initial stage of forming an expanded head by pouring concrete grout into the pile head, so that an expanded head with an expanded upper part is reliably formed at the bottom of the pile, and the technical problems in the prior art are effectively solved.

The present invention achieves the above technical objects by the following technical means.

A leakage-proof uplift pile comprises a prefabricated pile body and a pile head movably arranged at the bottom of the pile body, wherein the pile body comprises a bottom plate fixedly arranged at the lower end of the pile body, a boss matched with the pile head is arranged on the lower surface of the bottom plate, the pile head is formed by assembling a plurality of subshells with the same structure and size, and a grouting pipe sequentially penetrates through mounting holes in the bottom plate and the boss and extends into an inner cavity of the pile head; the bottom surface of the bottom plate is a first spherical surface, the bottom surface of the boss is a second spherical surface, and the edge of the upper end of the sub-shell matched with the first spherical surface is a third spherical surface; the first spherical surface, the second spherical surface and the third spherical surface have the same sphere center A, and the sphere center A is a pile tip point of the pile head.

Furthermore, sliding grooves which correspond to the sub-shells one to one are formed in the second spherical surface and extend in the expanding direction of the sub-shells; a sub-cover is fixed on the inner wall surface of the sub-shell, a guide rod is fixed above the sub-cover, and the top end of the guide rod is in sliding fit with the sliding groove through a sliding block.

Furthermore, the axis of the guide rod points to the center of sphere A, and the sliding block is matched with the sliding groove, so that the sub-shell is limited to only perform rotary motion around the center of sphere A.

Furthermore, the root of the sub-cover is positioned at the upper half part of the sub-shell, the sub-covers of all the sub-shells are spliced into a seamless cover body after being installed, and the seamless cover body divides the inner cavity of the pile head into an upper cavity communicated with the grouting pipe and a lower cavity isolated from the grouting pipe.

Further, the sub-covers include a main body portion and lower and upper half-wall portions on both sides of the main body portion and overlapping adjacent sub-covers.

Further, the upper surface of the lower half-wall part and the lower surface of the lower half-wall part form a superposed surface matched with the half-wall part of the adjacent sub-part; at least the superimposed surface is a spherical surface having a center A as a center.

Furthermore, each subshell is respectively provided with an inner notch and an outer notch at two side edges; the wall thickness of the sub-shell corresponding to the inner gap and the outer gap is half of that of the rest part; the inner and outer notches are complementary to each other, thereby allowing the subshells to be spliced end to end into a complete conical pile head.

Further, an inserting gap is formed between the root of the half-wall part of the sub-cover located at the inner notch and the inner notch.

The invention has the following beneficial effects:

compared with the prior art, the cooperation of the first spherical surface and the third spherical surface in the invention allows the fluid seal between the bottom of the pile body and the inner cavity of the pile head to be maintained in the process of correctly expanding the pile head, and can prevent concrete from leaking out of the inner cavity of the pile head when the pile head is not expanded in place, so that the grouting pressure does not need to be increased in the grouting process to supplement the decompression caused by the concrete leakage, and the phenomenon of first opening of the pile tip caused by overlarge grouting pressure can not occur naturally; the matching of the sliding chute and the guide rod can effectively prevent the pile head from moving away from the pile body along the axial direction of the pile body, and meanwhile, the sliding chute is arranged to take the point A as the center of a sphere and is matched with the guide rod of which the axis points to the point A, so that the sub-shell can be forced to only perform the rotating motion taking the point A as the pivot point, and further expanded in a correct mode; the arrangement of the sub-cover can effectively distribute the static pressure provided by concrete slurry mainly to the upper half part of the sub-shell, thereby ensuring the correct expansion mode of the pile head from the aspect of driving force; the measures act together, so that two error expansion modes of pile head separation and pile tip first opening are effectively overcome, the uplift pile can adapt to more comprehensive coating structure working conditions, and the control requirement on grouting pressure is reduced. In addition, when the pile head is expanded in a correct mode, the first spherical surface and the third spherical surface can be always tightly attached, and the gap problem caused by the attachment of the arc-shaped edge and the plane can be avoided.

Drawings

FIG. 1 is a schematic view of the combination of a leak-proof and uplift-resistant pile head;

FIG. 2 is a schematic view of the spherical bottom surfaces of the base plate and the boss;

FIG. 3 is a schematic view of the arrangement of the sliding grooves on the bosses;

FIG. 4 is an enlarged partial schematic view of the circled portion of FIG. 3;

FIG. 5 is a schematic view of the sub-shell of the belt cover as closed;

FIG. 6 is a three-dimensional schematic view of a sub-shell of the band cover;

FIG. 7 is a three-dimensional schematic view of a sub-lid;

FIG. 8 is a top view of FIG. 5;

FIG. 9 is a schematic view of the superimposed surfaces of the sub-lids;

FIG. 10 is a top view of FIG. 6;

FIG. 11 is a schematic view of a star-shaped opening;

FIG. 12 is a schematic view of the subshells being rotationally expanded about the spherical center A;

FIG. 13 is a schematic view of a prior art pile head being removed from a pile;

fig. 14 is a prior art toe-in diagram.

In the figure: 1-leakage-proof uplift pile, 2-pile body, 21-bottom plate, 211-first spherical surface, 212-mounting hole, 22-boss, 221-second spherical surface, 222-chute, 3-grouting pipe, 4-pile head, 41-subshell, 42-inner gap, 43-outer gap, 44-inner half wall, 45-outer half wall, 46-third spherical surface, 5-subshell, 51-lower half wall part, 52-upper half wall part, 53-superposition surface, 6-guide column and 61-sliding block.

Detailed Description

The invention will be further described with reference to the following figures and specific examples, but the scope of the invention is not limited thereto.

As shown in fig. 1 and 2, the leakage-proof uplift pile comprises a prefabricated columnar pile body 2, wherein the pile body 2 comprises a bottom plate 21 fixedly arranged at the lower end, a boss 22 coaxial with the bottom plate 21 is arranged on the lower surface of the bottom plate 21, and a mounting hole 212 penetrating through the bottom plate 21 and the boss 22 is further arranged at the center of the bottom plate 21. The one-way grouting pipe 3 is inserted into the mounting hole 212, the outer wall of the grouting pipe 3 is hermetically arranged with the inner wall of the mounting hole 212, and the grouting pipe 3 is arranged to be positioned relative to the mounting hole 212, for example, clamping elements such as clamping rings are respectively arranged at the upper and lower positions of the grouting pipe 3 on the bottom plate 21, so that the grouting pipe 3 is kept stable during high-pressure grouting and cannot be separated from the mounting hole 212. The grouting pipe 3 can be a sleeve valve pipe or other structural forms capable of realizing high-pressure unidirectional grouting.

The lower part of the bottom plate 21 is movably provided with a pile head 4, and the pile head 4 is of a conical structure matched with the pile body 2.

The pile head 4 has a housing and a cavity enclosed by the housing. The housing is assembled by a plurality of sub-housings 41 as shown in fig. 6, and in this embodiment, the housing is assembled by four sub-housings 41, it should be understood that the number of the sub-housings 41 defined herein is only an example for convenience of description, and is not the only limitation or preferred manner.

As shown in fig. 6, each of the sub-housings 41 has the same shape and size, and each of the sub-housings 41 is provided at both side edges thereof (referring to the edges extending in the direction of the generatrix of the conical structure) with an inner notch 42 and an outer notch 43, respectively (the inner and outer are considered as the inner and outer of the conical structure herein). Accordingly, the wall thickness of the corresponding sub-shell 41 at the inner and

outer notches

42 and 43 is half of the wall thickness of the remaining portion, thereby forming outer and

inner half walls

45 and 44 at the inner and

outer notches

42 and 43. The inner gap 42 is complementary to the outer gap 43, allowing the four subshells 41 to be spliced into a complete conical pile head 4; the diameter of the conical bottom of the conical pile head 4 formed when the inner notch 42 and the outer notch 43 are completely spliced and overlapped is not larger than that of the pile body 2.

As shown in fig. 2 and 3, the bosses 22 on the lower surface of the bottom plate 21 have a shape and size matching the inner cavity of the conical stub head 4, thereby allowing the inner surfaces of the four subshells 41 to completely conform to the outer periphery of the bosses 22.

As shown in fig. 2 and 3, the bottom surface of the bottom plate 21 is a spherical surface, i.e., a first spherical surface 211; the bottom surface of the boss 22 is also a spherical surface, i.e. a second spherical surface 221; the edge of the upper end of the sub-shell 41 contacted and matched with the first spherical surface 211 is also a spherical surface, namely a third spherical surface 46; the first spherical surface 211, the second spherical surface 221 and the third spherical surface 46 all have the same spherical center a, and the spherical center a is a cone tip point of the pile head 4. Therefore, when the pile head 4 is expanded in a correct manner as shown in fig. 12, that is, when the sub-shell 41 is expanded outward in a manner of rotating around the center a, the first spherical surface 211 and the third spherical surface 46 can always keep a tight fit, and a gap problem caused by the fit of the arc-shaped edge and the plane surface does not occur.

In order to make the pile head 4 be correctly expanded under various conditions, the embodiment is further improved as follows:

as shown in fig. 3 and 4, the second spherical surface 221 is provided with a plurality of sliding grooves 222, and the sliding grooves 222 correspond to the sub-shells 41 one to one; on the other hand, a sub-cover 5 is fixed on the inner wall surface of the sub-shell 41, a guide rod 6 is fixed above the sub-cover 5, the axis of the guide rod 6 points to the center of sphere a, and the top end of the guide rod 6 is in sliding fit with the sliding chute 222 through a slide block 61. The cooperation of the slide 61 with the slide groove 222 limits the sub-housing 41 to perform only a rotational movement around the center of sphere a, and in particular, the slide 61 with a larger cross-sectional size than the guide rod 6, for example, the spherical or square slide 61 can be used to cooperate with the spherical or T-shaped slide groove 222, so that the slide groove 222 can drag the sub-housing 41 through the slide 61 and the guide rod 6, thereby preventing the pile head 4 from being detached from the pile.

As shown in fig. 1, 5, 6, 8 and 9, the connection portion (hereinafter referred to as root portion) of the sub-cap 5 and the corresponding sub-shell 41 is located at the upper half portion of the sub-shell 41, and when the sub-shells 41 are spliced into the conical pile head 4 in the initial state, the sub-caps 5 on the inner wall surfaces of all the sub-shells 41 are spliced with each other to form a seamless cap body which divides the inner cavity of the pile head 4 into an upper cavity communicated with the grouting pipe 3 and a lower cavity isolated from the grouting pipe 3.

Therefore, at the initial stage of grouting, after the concrete slurry is injected from the grouting pipe 3, the concrete slurry is firstly trapped in the upper chamber, and the static pressure is applied to the upper half side wall of the subshell 41 and the subshell 5 after the upper chamber is full; since the root of the sub-cover 5 is fixed to the upper half of the sub-shell 41, the static pressure applied to the sub-cover 5 is also transmitted to the upper half of the sub-shell 41 through the root, thereby causing the sub-shell 41 to expand rotationally about the center of sphere a. This arrangement allows construction without concern for excessive grouting pressure, as the concrete will take over and transfer the downward impact force from the sub-cover 5 to the upper half of the sub-shell 41, thereby turning into a bulging pushing force on the upper half of the sub-shell 41.

As shown in fig. 6 to 10, the sub-cover 5 includes a main body portion and two half-wall portions (i.e., a lower half-wall portion 51 and an upper half-wall portion 52) located on both sides of the main body portion and overlapping with the adjacent sub-cover 5; the lower half-wall 51 is located at one side of the inner gap 42, and a plugging gap 54 as shown in fig. 6 is formed between the root of the lower half-wall and the inner gap 42, and the plugging gap 54 is used for matching the inner half-wall 44 of the adjacent sub-shell 41 and the outer half-wall 45 of the current sub-shell 41 in a superposition manner. It should be understood that the insertion gap 54 is only present on one side of the inner recess 42, but does not limit the arrangement of the lower half-wall 51 and the upper half-wall 52, i.e. the positions of the half-wall parts are interchangeable. The upper surface of the lower half-wall part 51 and the lower surface of the upper half-wall part 52 form an overlapping surface 53 matched with the upper half-wall part and the lower half-wall part of the adjacent subshell 5; at least the superimposed surface 53 is a spherical surface having the center a as the center, in other words, the upper and lower surfaces of the main body portion may not be spherical surfaces. This arrangement allows partial overlap between adjacent subshells 5 to still be maintained by the half-wall portions when the subshells 41 are expanded and only the star-shaped openings 7 as illustrated in figure 11 are formed; the star-shaped openings 7 facilitate retarding the rate of opening of the fluid passageway between the upper and lower chambers, thereby maintaining the difference in static pressure exerted by the concrete slurry on the upper and lower halves of the sub-shell 4.

The present invention is not limited to the above-described embodiments, and any obvious improvements, substitutions or modifications can be made by those skilled in the art without departing from the spirit of the present invention.

Claims

1. A leak-proof uplift pile comprises a prefabricated pile body (2) and a pile head (4) movably arranged at the bottom of the pile body (2), wherein the pile body (2) comprises a bottom plate (21) fixedly arranged at the lower end of the pile body, a boss (22) matched with the pile head (4) is arranged on the lower surface of the bottom plate (21), the pile head (4) is formed by assembling a plurality of subshells (41) with the same structure and size, and a grouting pipe (3) sequentially penetrates through mounting holes (212) in the bottom plate (21) and the boss (22) and extends into an inner cavity of the pile head (4); the novel spherical shell is characterized in that the bottom surface of the bottom plate (21) is a first spherical surface (211), the bottom surface of the boss (22) is a second spherical surface (221), and the edge of the upper end of the sub-shell (41) matched with the first spherical surface (211) is a third spherical surface (46); the first spherical surface (211), the second spherical surface (221) and the third spherical surface (46) have the same sphere center A, and the sphere center A is a pile tip point of the pile head (4).

2. A leakage-proof uplift pile as claimed in claim 1, wherein the second spherical surface (221) is provided with sliding grooves (222) corresponding to the sub-shells (41) one by one, and the sliding grooves (222) extend along the expanding direction of the sub-shells (41); a sub-cover (5) is fixed on the inner wall surface of the sub-shell (41), a guide rod (6) is fixed above the sub-cover (5), and the top end of the guide rod (6) is in sliding fit with the sliding groove (222) through a sliding block (61).

3. A leak-proof and uplift pile according to claim 2, wherein the axis of the guide rod (6) points to the center of sphere a, and the sliding block (61) is matched with the sliding groove (222) to limit the sub-shell (41) to only perform a rotation motion around the center of sphere a.

4. A leak-proof and uplift pile according to claim 3, wherein the root of the sub-cover (5) is located at the upper half part of the sub-shell (41), the sub-covers (5) of all the sub-shells (41) are spliced into a seamless cover body after being installed, and the seamless cover body divides the inner cavity of the pile head (4) into an upper cavity communicated with the grouting pipe (3) and a lower cavity isolated from the grouting pipe (3).

5. A leak-proof uplift pile according to claim 4, wherein the sub-cover (5) comprises a main body part and a lower half wall part (51) and an upper half wall part (52) which are positioned at both sides of the main body part and are overlapped with the adjacent sub-cover (5).

6. A leak-proof uplift pile according to claim 5, wherein the upper surface of the lower half-wall part (51) and the lower surface of the lower half-wall part (52) constitute a superimposed surface (53) matching with the half-wall part of the adjacent sub-cover (5); at least the overlapping surface (53) is a spherical surface having a spherical center A as the spherical center.

7. A leak-proof uplift pile according to claim 6, wherein each of the sub-shells (41) is provided at both side edges thereof with an inner notch (42) and an outer notch (43), respectively; the wall thickness of the corresponding sub-shell (41) at the inner gap (42) and the outer gap (43) is half of that of the rest part; the inner gap (42) is complementary to the outer gap (43) to allow the sub-shells (41) to be spliced end to form a complete conical pile head (4).

8. A leak-proof and uplift pile according to claim 7, wherein the root of the half-wall part of the sub-cover (5) at the inner gap (42) and the inner gap (42) have a plug-in gap (54).