Double-steel-pipe supporting pile structure and construction method

Abstract

A double-steel-pipe supporting pile structure, comprising a pile body, the pile body comprising an outer pipe, the outer pipe being sleeved with an inner pipe, the outer pipe and the inner pipe being fixedly connected through a plurality of longitudinal ribs in the axial direction and being fixedly connected through at least two annular transverse ribs in the radial direction, adjacent two transverse ribs forming a partition cavity communicated in the circumferential direction, one connecting pipe being fixedly connected to each layer of partition cavities, one end of the connecting pipe being communicated with the partition cavity, and the other end of the connecting pipe being arranged between the outer pipe and the inner pipe in the axial direction and penetrating through the topmost transverse rib, a plurality of through holes A being distributed on the wall of the outer pipe, a one-way valve A being mounted in each through hole A, a plurality of through holes B being distributed on the wall of the inner pipe, a one-way valve B being mounted in each through hole B, and the flow directions of the one-way valve A and the one-way valve B being both set from the partition cavity to the outside. The double-steel-pipe supporting pile is used, the water injection pressure bearing is used to overcome the "soil plug effect" in use, and the repeated use of the steel pipe supporting pile is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of construction, in particular to a double-steel-pipe supporting pile structure and a construction method. BACKGROUND

[0002] Supporting piles are mainly used for supporting the side of a foundation pit in civil engineering, and are usually designed as cast-in-place piles or pipe piles. The main disadvantage is that after the main project is completed, the rock-soil between the supporting structure and the main structure is backfilled, and the supporting pile has no value at this time, but it cannot be removed, resulting in waste.

[0003] During construction, a steel pipe is usually used as a supporting pile. When a steel pipe supporting pile is used, in order to reduce the lateral friction on the outside of the pile, the steel pipe is sunk into the soil by using the hole in the pipe to penetrate the soil, which will cause a "soil plug effect", increasing the resistance of the steel pipe sinking into the rock-soil. In order to be reused, the steel pipe is usually pulled out after use, and the "soil plug effect" causes the steel pipe to deform, making it difficult to achieve reuse. SUMMARY

[0004] The present application provides a double-steel-pipe supporting pile structure and a construction method, which uses a double-layer steel pipe supporting pile to overcome the "soil plug effect" during use by using water injection to bear pressure, thereby achieving the reuse of the steel pipe supporting pile.

[0005] In order to solve the above technical problems, the present application provides the following technical solutions:

[0006] The present application discloses,

[0007] A double-steel-pipe supporting pile structure, comprising,

[0008] A pile body, the pile body comprising an outer pipe and an inner pipe, the inner pipe being sleeved in the outer pipe, the outer pipe and the inner pipe being fixedly connected along the axial direction by a plurality of longitudinal ribs and being fixedly connected along the radial direction by at least two annular transverse ribs, adjacent two transverse ribs forming a partition cavity connected in the circumferential direction, one connecting pipe being fixedly connected to each layer of partition cavities, one end of the connecting pipe being connected to the partition cavity and the other end being arranged between the outer pipe and the inner pipe along the axial direction and penetrating the topmost transverse rib, a plurality of through holes A being distributed on the wall of the outer pipe, a one-way valve A being installed in each through hole A, a plurality of through holes B being distributed on the wall of the inner pipe, a one-way valve B being installed in each through hole B, the flow directions of the one-way valve A and the one-way valve B being arranged from the partition cavity to the outside.

[0009] Further, the through holes A and the through holes B are in the shape of a horn mouth with the outside being larger than the inside.

[0010] Further, the pile body can be divided into a bottom pile and a connecting pile, the top end of the bottom pile and the two ends of the connecting pile are respectively provided with a connecting part, the connecting part comprises an annular end plate A fixedly connected to the end part of the outer pipe, a penetrating hole for penetrating a water pipe is arranged on the annular end plate A at the top end of the bottom pile and the connecting pile, a flange is welded on the outer edge of the annular end plate A, and the bottom pile and the connecting pile, the connecting pile and another connecting pile are fixedly connected through the flange by bolts.

[0011] Further, the bottom pile is fixedly connected with an annular sealing plate at the lower end, the annular sealing plate is fixedly connected to the outer pipe and the inner pipe, and a fixed ring in a triangular cross section is fixedly connected to the lower end surface of the annular sealing plate.

[0012] Further, the connecting pipe is provided with a connecting joint in the connecting part, and the connecting joint can be connected by penetrating the penetrating hole through the water pipe from the outside.

[0013] Further, a threaded hole is arranged on the outer edge of the penetrating hole, and the penetrating hole can be blocked by a blocking plate through the threaded hole by bolts.

[0014] Further, the longitudinal ribs are arranged uniformly along the inner wall of the outer pipe.

[0015] A construction method of a double-steel-pipe supporting pile structure, comprising the following steps,

[0016] S1, pile pipe positioning,

[0017] The bottom pile is moved to a specified position, and the upper end connecting part of the bottom pile is connected to the pile driver;

[0018] S2, water injection and vibration pipe pressing,

[0019] Before the bottom pile (20) is pressed into the soil layer, a water injection pipe is connected to the connecting pipe in the upper end connecting part of the bottom pile by penetrating the penetrating hole on the bottom pile, water is injected into the cavity in the soil at a depth of 0.4-0.7 m after the lowermost cavity of the bottom pile is pressed into the soil, the water pressure is greater than the pressure of the soil layer, and then the pipe is gradually vibrated, water is injected into the cavity in the soil layer at different depths according to the soil condition, and the water can flow out through the one-way valve A and the one-way valve B to wet the soil layer and reduce the friction of the soil layer;

[0020] S3, pile connection and vibration pipe pressing,

[0021] When the bottom pile is pressed into the soil to the top of the soil layer 0.5-1m, the connecting joint of the connecting pipe in the connecting part of the bottom pile and the connecting part of the upper part of the connecting pile is connected through the pressure-resistant hose, and the upper end of the bottom pile is closed through the blocking plate, the flanges of the two connecting parts are connected through the bolts, and the water injection pipe is connected through the connecting joint in the connecting part of the upper part of the connecting pile; after the pile is connected, water is injected into the cavity according to the situation of the pile body into the soil, the water pressure in the cavity is greater than the lateral pressure of the soil layer, and the pressure pipe is vibrated; when the top of the first section of the connecting pile is 50-80cm above the soil layer, the pile connecting process is repeated until the pile driving is completed.

[0022] S4, water injection, pile pulling,

[0023] The upper connecting part of the topmost connecting pile is connected to the pipe pulling machine, the connecting pipe is connected through the water injection pipe, the cavity in the soil layer is uniformly injected with water, the water pressure is the maximum water injection pressure when the pile is driven, and the pipe is pulled at the same time; when the upper part of each cavity is 0.4m-0.7m from the ground, stop injecting water into the cavity, until the connecting part of the pile body is pulled out of the ground 0.4-0.7m, remove the connecting bolts on the flanges, then connect the next section of the pile body to the pipe pulling machine, and repeat the above pipe pulling process until all the pipes are pulled out.

[0024] The beneficial effects achieved by the present application are:

[0025] By setting the pile body as a double-pipe structure, water with a certain pressure is injected into the double-pipe and multiple cavities, which provides lubrication and reduces resistance when driving the pile, and provides filling to overcome the soil plug effect when pulling the pile, so that the pile body can be reused.

[0026] In order to better overcome the soil plug effect and avoid deformation of the bottom pile during use, a one-way valve A is installed in the outer pipe, and a one-way valve B is installed on the inner pipe, so that the water in the cavity can flow out through the one-way valve A and the one-way valve B to fill the space and avoid the soil plug effect, and the through holes A and B are set as a horn-shaped opening with a large outer diameter and a small inner diameter, which can avoid lateral extrusion and damage of the one-way valve during pile driving.

[0027] By setting the through hole, the water injection pipe is conveniently inserted into the connecting part from the side to connect the connecting joint of the connecting pipe, and pile driving is facilitated.

[0028] By installing a fixing ring at the bottom of the bottom pile, the bottom of the fixing ring is provided with a sharp corner, which facilitates the entry of the bottom pile into the soil layer.

[0029] By setting the pile body as a connecting pile and a bottom pile, the length of the bottom pile is connected when the length of the bottom pile is not enough, and the use needs are met.

[0030] By setting the flange connection package to connect the connecting pile and the bottom pile, the stability of the connection between the connecting pile and the connecting pile is improved.

[0031] The connecting joint is arranged to facilitate the connection between the water injection pipe and the connecting pipe.

[0032] The threaded hole is arranged outside the through hole, so that the through hole can be blocked by the blocking plate when the through hole is not used, thereby preventing soil from entering the connecting part. BRIEF DESCRIPTION OF DRAWINGS

[0033] The accompanying drawings are included to provide a further understanding of the present application, and are incorporated in and constitute a part of this specification, illustrate embodiments of the present application and serve to explain the present application, and do not constitute a limitation of the present application. In the drawings:

[0034] Fig. 1 The patent structure schematic diagram.

[0035] Fig. 2 The patent bottom pile internal along a longitudinal rib section structure schematic diagram.

[0036] Fig. 3 The end part of the bottom makeup structure schematic diagram.

[0037] Fig. 4 The patent connecting pile end structure schematic diagram.

[0038] Fig. 5 The end part of the connecting pile structure section structure diagram

[0039] Fig. 6 The patent through hole A, through hole B place enlarged structure schematic diagram. EMBODIMENT

[0040] The preferred embodiments of the present application are described below in conjunction with the accompanying drawings, and it should be understood that the preferred embodiments described herein are only used to illustrate and explain the present application, and are not used to limit the present application.

[0041] As shown in Figs. 1-4 A double-steel pipe supporting pile structure, comprising,

[0042] A pile body 10, the pile body 10 includes an outer tube 101, the outer tube 101 is sleeved with an inner tube 102, the outer tube 101 and the inner tube 102 are fixedly connected along the axial direction through a plurality of longitudinal ribs 103, and are fixedly connected along the radial direction through at least two annular transverse ribs 104, adjacent two transverse ribs 104 form a compartment 1041 communicated in the circumferential direction, each layer of compartment 1041 is fixedly connected with a connecting pipe 105, one end of the connecting pipe 105 is communicated with the compartment, and the other end is arranged between the outer tube 101 and the inner tube 102 along the axial direction and passes through the topmost transverse rib 104, a plurality of through holes A1011 are distributed on the wall of the outer tube 101, a one-way valve A1012 is installed in the through hole A1011, a plurality of through holes B1021 are distributed on the wall of the inner tube 102, a one-way valve B1022 is installed in the through hole B1021, and the flow directions of the one-way valve A1012 and the one-way valve B1022 are both arranged from the compartment 1041 to the outside.

[0043] Further, the through hole A1011 and the through hole B1021 are trumpet-shaped with the outer large and the inner small.

[0044] Further, the pile body 10 can be divided into a bottom pile 20 and a connecting pile 30, the top end of the bottom pile 20 and the two ends of the connecting pile 30 are respectively provided with a connecting part 40, the connecting part 40 includes an annular end plate A401 fixedly connected to the end of the outer tube 101, a penetrating hole 402 for penetrating a water pipe is arranged on the annular end plate A401 at the top end of the bottom pile 20 and the connecting pile 30, a flange 403 is welded outside the annular end plate A401, and the connecting part 40 fixes the bottom pile 20 and the connecting pile 30, and the connecting pile 30 and another connecting pile 30 by bolt connecting the flange 403.

[0045] Further, the bottom pile 20 is fixedly connected with an annular sealing plate 201, the annular sealing plate 201 is fixedly connected to the outer tube 101 and the inner tube 102, and a fixing ring 2011 with a triangular cross section is fixedly connected to the lower end surface of the annular sealing plate 201.

[0046] Further, the connecting pipe 105 is provided with a connecting joint 1051 in the connecting part 40, and the connecting joint 1051 can be connected by an external water pipe through the penetrating hole 402.

[0047] Further, a threaded hole is arranged outside the penetrating hole 402, and the penetrating hole 402 can be blocked by bolt connecting the threaded hole through a blocking plate.

[0048] Further, the longitudinal ribs 103 are uniformly arranged on the inner wall of the outer tube 101.

[0049] Specifically, three cavities are arranged in the bottom pile and the connecting pile respectively, each cavity has a height of 1-2m, the one-way water flow pressure of the one-way valve A1012 and the one-way valve B1022 is greater than or equal to 0.15MPA, the wall thickness of the steel pipe of the outer pipe 101 is 10-20mm, the wall thickness of the steel pipe of the inner pipe 102 is 8-10mm, the hole diameter of the through hole A1011 and the through hole B2011 is 10-20mm.

[0050] A double-steel-pipe supporting pile structure construction method, steps are as follows,

[0051] S1, pile pipe positioning and vibration pressure pipe,

[0052] The bottom pile 20 is moved to a specified position, and the bottom pile 10 is gradually pressed into the soil layer by a pile driver;

[0053] S2, water injection and vibration pressure pipe,

[0054] The water injection pipe is connected to the connecting pipe 105 in the upper end connecting part 40 of the bottom pile 20 through the penetrating hole 402 on the bottom pile 20, 0.4-0.7m after the lowermost cavity 1041 of the bottom pile 20 is pressed into the soil, water injection into the cavity 1041 in the soil is started, the water injection pressure is greater than the pressure of the soil layer, and then the vibration pressure pipe is gradually vibrated, the cavity 1041 in the soil layer at different depths is injected according to the soil quality, and the water can flow out through the one-way valve A1012 and the one-way valve B1022 to moisten the soil layer and reduce the friction of the soil layer;

[0055] S3, pile connection and vibration pressure pipe,

[0056] Pile connection, when the bottom pile 20 is pressed into the soil to a height of 0.5-1m above the soil layer, the connecting joint 1051 of the connecting pipe 105 in the bottom connecting part 40 of the connecting pile 30 and the upper connecting part 40 of the bottom pile 20 is connected through a pressure-resistant hose, the upper end penetrating hole 402 of the bottom pile 20 is closed through a plugging plate, the flanges 403 of the two connecting parts 40 are connected through bolts, and the water injection pipe is connected to the connecting joint 1051 in the connecting part 40 through the upper penetrating hole 402 of the connecting pile 30; after the pile connection is completed, water injection is carried out in the cavity 1041 in the soil according to the situation of the pile body 10 entering the soil, the water injection pressure in the cavity 1041 is greater than the lateral pressure of the soil layer, and the vibration pressure pipe is vibrated, the pile connection process is repeated when the top of the first connecting pile 30 is 50-80cm above the soil layer, and the pile driving is completed;

[0057] S4, water injection and pile pulling,

[0058] The connecting part 40 of the upper part of the top connecting pile 30 is connected to the pipe pulling machine, the connecting pipe 105 is connected to the cavity 1041 in the soil layer through the water injection pipe passing through the connecting hole 402 on the connecting part 40, and water is uniformly injected into the cavity 1041 in the soil layer, the water pressure is the maximum water injection pressure when the pile is pressed, and the pipe is pulled at the same time. When the upper part of each cavity 1041 is 0.4-0.7 m away from the ground, stop injecting water into the cavity 1041, until the connecting part 40 of the pile body 10 is pulled out of the ground 0.4-0.7 m, remove the connecting bolts on the flange 403, then connect the next pile body 10 to the pipe pulling machine, and repeat the above pipe pulling process until all the piles are pulled out.

[0059] Specific embodiments are as follows,

[0060] First, the bottom pile 20 and the connecting pile 30 are set to 5 m long, the separation cavity 1041 is set to 1.6 m, the pile driving depth is designed to be 14 m, the lateral stress of each soil layer is determined according to the thickness of each soil layer in the engineering survey data, the area of the steel pile lateral wall in each soil layer (the outer wall area of the outer pipe + the outer wall area of the steel inner pipe) is calculated according to the pile length in each soil layer, then multiplied by the friction coefficient of each soil layer and the steel pipe, the lateral friction resistance of the soil to the steel pipe in each soil layer is obtained, and 1.2-1.5 times the sum of the resistances is the maximum dynamic power value of the pile hammer hydraulic pressure.

[0061] The specific calculation is as follows, the actual measured soil data in a certain area is as follows, and an example calculation is performed;

[0062] The soil layer is silt with a depth of 0-6 m,

[0063] The effective density of the soil is calculated, the density is 18.0 (KN / m3), the relative density is 2.70, the water content is 35%, the buoyant density = (2.70-1) x 18.0 (KN / m3), 2.70 x (1+0.35)=8.4 N / m3;

[0064] The vertical self-weight stress in the soil is calculated (KPA), within 3.6 m, 18 x 3.6=0.065 MPA,

[0065] Within 3.6-6 m, 65+8.4 x (6-3.6)=0.085 MPA;

[0066] The soil layer is silty clay with a depth of 6-9 m,

[0067] The effective density of the soil is calculated, the density is 18.9 (KN / m3), the relative density is 2.72, the water content is 34.3%, the buoyant density = (2.72-1) x 18.9 (KN / m3), 2.72 x (1+0.343)=8.9 N / m3;

[0068] The vertical self-weight stress in the soil is calculated (KPA), within 6-9 m, 85+8.9 x (9-6)=0.112 MPA

[0069] Soil layer, clay depth 9~15 meters,

[0070] Effective density of soil calculation, density 19.3 (KN / m3)

[0071] Soil vertical self-weight stress calculation (KPA) 9~15 meters, 112+10×(9-3.6)=0.166MPA, 166+19.3×(15.0-9.0)=0.282MPA;

[0072] When piling,

[0073] First, the bottom pile is vibrated into the soil about 2 meters or so, and the water pressure of 0.2MPA is injected into the first section of the soil cavity;

[0074] Then press in about 3.6 meters, and inject water pressure 0.2MPA into the second section of the cavity;

[0075] When pressed in about 4.5 meters, stop pressing and injecting water, connect the bottom pile and the first connecting pile through the flange, and then continue to press down;

[0076] Press in about 5.4 meters, and inject water pressure 0.2MPA into the third section of the cavity of the bottom pile;

[0077] Press in about 7.0 meters, and inject water pressure 0.2MPA into the first section of the cavity of the first connecting pile;

[0078] Press in about 8.6 meters, and inject water pressure 0.2MPA into the second section of the cavity of the first connecting pile;

[0079] When pressed in about 9.5 meters, stop pressing and injecting water, and connect the second connecting pile;

[0080] Press in about 10.4 meters, and inject water pressure 0.2MPA into the third section of the cavity of the first connecting pile, and at the same time, increase the water pressure of the first section of the cavity of the bottom pile to 0.3MPA;

[0081] Press in about 12.0 meters, and open the water pressure 0.2MPA into the first section of the cavity of the second connecting pile, and at the same time, increase the water pressure of the second section of the cavity of the bottom pile to 0.3MPA;

[0082] Press to about 13.6 meters, and open the water pressure 0.2MPA into the second section of the cavity of the second connecting pile, and at the same time, increase the water pressure of the third section of the cavity of the bottom pile to 0.3MPA;

[0083] When pressed to about 14.0 meters, stop vibrating and pressing, and reduce the water pressure to zero;

[0084] Note: The above is the water pressure set according to the soil pressure change, and a water pressure of 0.3MPA greater than the maximum soil pressure can also be used. If the pipe pile is pressed in the just-constructed cement-soil water-stop curtain, no water pressure is needed. If a pipe partition cavity is in a silt soil layer, the partition cavity does not increase water pressure.

[0085] When the pile is pressed, except for the third section partition cavity of the second connecting pile, the other partition cavities uniformly use a water pressure of 0.3MPA to press the pipe, and when the second section partition cavity of the second connecting pile is about 0.5m from the ground surface, the water pressure of the partition cavity is stopped to continue pressing the pipe. (That is, when the top of each pipe partition cavity is about 0.5m from the ground surface, the water pressure of the partition cavity is stopped.)

[0086] In addition, when each section connecting part is 0.5m above the ground surface, the flange connection of the connecting part is removed, the pressure-resistant hose between the connecting joints of the connecting pipe is removed, and the water injection pipe is connected to the connecting pipe joint that has not been pulled out of the soil layer from the through hole, and water injection and pipe pulling are performed until all the pipes are pulled out.

[0087] Finally, it should be noted that the above only describes the preferred embodiments of the present application and is not intended to limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent replacements to some technical features. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A double steel pipe support pile structure, characterized by, The utility model relates to a pile body (10) that includes an outer tube (101) and an inner tube (102) sleeved in the outer tube (101), the outer tube (101) and the inner tube (102) are fixedly connected by a plurality of longitudinal ribs (103) in the axial direction and are fixedly connected by at least two annular transverse ribs (104) in the radial direction, two adjacent transverse ribs (104) form a compartment (1041) connected in the circumferential direction, each layer of compartment (1041) is fixedly connected to a connecting pipe (105), one end of the connecting pipe (105) is connected to the compartment, and the other end is arranged between the outer tube (101) and the inner tube (102) in the axial direction and passes through the topmost transverse rib (104), a plurality of through holes A (1011) are distributed on the wall of the outer tube (101), a one-way valve A (1012) is arranged in the through hole A (1011), a plurality of through holes B (1021) are distributed on the wall of the inner tube (102), a one-way valve B (1022) is arranged in the through hole B (1021), and the flow directions of the one-way valve A (1012) and the one-way valve B (1022) are both arranged from the compartment (1041) to the outside. The through hole A (1011) and the through hole B (1021) are in the shape of a horn mouth with a large outer diameter and a small inner diameter.

2. A double steel pipe support pile structure according to claim 1, wherein The pile body (10) can be divided into a bottom pile (20) and a connecting pile (30), the top end of the bottom pile (20) and the two ends of the connecting pile (30) are respectively provided with a connecting part (40), the connecting part (40) includes an annular end plate A (401) fixedly connected to the end of the outer tube (101), a penetrating hole (402) for penetrating a water pipe is arranged on the annular end plate A (401) at the top end of the bottom pile (20) and the connecting pile (30), a flange (403) is welded outside the annular end plate A (401), and the bottom pile (20), the connecting pile (30) and another connecting pile (30) are fixedly connected through the flange (403) by bolt connection.

3. A double steel pipe support pile structure according to claim 1, wherein The bottom pile (20) is fixedly connected to an annular sealing plate (201), the annular sealing plate (201) is fixedly connected to the outer tube (101) and the inner tube (102), and the lower end surface of the annular sealing plate (201) is fixedly connected to a fixing ring (2011) in the shape of a triangle in cross section.

4. A twin steel pipe support pile structure according to claim 3, wherein A connecting joint (1051) is arranged in the connecting part (40) of the connecting pipe (105), and the connecting joint (1051) can be connected from the outside through the penetrating hole (402) by a water pipe.

5. A twin steel pipe support pile structure according to claim 3, wherein A threaded hole is arranged outside the penetrating hole (402), and the penetrating hole (402) can be blocked by bolt connection of the threaded hole.

6. A double-skin wall construction according to any one of claims 3 to 5, wherein, The longitudinal ribs (103) are evenly arranged on the inner wall of the outer tube (101).

7. A twin steel pipe support pile structure according to claim 1, wherein The steps are as follows, 8. A method for constructing a double steel pipe support pile structure using the double steel pipe support pile structure according to claim 5, characterized by, S1, pile tube positioning, The bottom pile (20) is moved to a specified position, and the upper end connecting part (40) of the bottom pile (20) is connected to a pile driver; S2, water injection and vibration pressure pipe, ​ Before the bottom pile (20) is pressed into the soil, the water injection pipe is connected to the connecting pipe (105) in the upper end connecting part (40) of the bottom pile (20) through the connecting hole (402) on the bottom pile (20). When the lowermost part of the bottom pile (20) is pressed into the soil and the upper part is 0.4-0.7m from the ground, water injection into the soil is started. The water injection pressure is greater than the pressure of the soil layer, and the pressure pipe is gradually vibrated. According to the soil quality, water is injected into the soil layer at different depths. The water can flow out through the one-way valve A (1012) and the one-way valve B (1022) to moisten the soil and reduce the friction of the soil layer. S3, pile connection, vibration pressure pipe, When the bottom pile (20) is pressed into the soil to a height of 0.5-1m above the soil layer, the bottom connecting part (40) of the connecting pile (30) is connected to the connecting pipe (105) in the upper connecting part (40) of the bottom pile (20) through the pressure-resistant hose, and the upper end connecting hole (402) of the bottom pile (20) is closed by the blocking plate. The flanges (403) of the two connecting parts (40) are connected by bolts, and the water injection pipe is connected to the connecting joint (1051) in the connecting part (40) through the connecting hole (402) on the upper part of the connecting pile (30). After the pile connection is completed, water is injected into the soil according to the situation of the pile body (10) entering the soil. The water injection pressure in the soil is greater than the lateral pressure of the soil layer, and the pressure pipe is vibrated. When the top of the first connecting pile (30) is 50-80cm above the soil layer, the pile connection process is repeated until the pile driving is completed. S4, water injection, pile pulling, The upper connecting part (40) of the topmost connecting pile (30) is connected to the pipe pulling machine, and the water injection pipe is connected to the connecting pipe (105) through the connecting hole (402) on the connecting part (40) to uniformly inject water into the soil layer. The water pressure is the maximum water injection pressure during pile driving, and the pipe is pulled out at the same time. When the upper part of each soil layer is 0.4-0.7m from the ground, water injection into the soil layer is stopped. When the connecting part (40) of the pile body (10) is pulled out to a height of 0.4-0.7m from the ground, the connecting bolts on the flanges (403) are removed, and the next pile body (10) is connected to the pipe pulling machine. The above pile pulling process is repeated until all the piles are pulled out.

Images