Spiral soil extrusion casing followed by concrete pouring pile method

Abstract

This invention relates to a method for pile formation using a spiral soil displacement drilling casing and subsequent concrete pouring, comprising the following steps: After the spiral soil displacement pile driver is positioned, the first power head is started to rotate and drill downwards to form a hole, and then the second power head is started to drive the casing to rotate and drill downwards to form a hole, until the soil displacement drill bit and the casing of the second power head reach the designed depth and drilling stops; the connection between the second power head and the casing is disconnected, and the concrete pump connected to the first power head is started to pump concrete into the borehole while simultaneously lifting the first and second power heads upwards until the soil displacement drill bit is completely removed from the casing; the reinforcing cage is locked into the positioning component using a locking component, and then lowered along the casing to a predetermined height, while pumping concrete into the casing until the designed pile top elevation is reached; the second power head is reconnected to the casing using the locking component, and the second power head is started to rotate and lift upwards until the casing is completely removed from the soil layer, thus completing pile formation. This application facilitates the rapid and stable lowering of the reinforcing cage.

Description

Technical Field

[0001] This invention relates to the field of cast-in-place pile construction, and in particular to a method for forming piles by spiral soil displacement hole forming casing followed by concrete pouring. Background Technology

[0002] With the rapid development of my country's economic and urban construction, and the large-scale construction of high-rise buildings and underground projects, modern pile foundations can be divided into three main categories based on the impact of the pile forming method on the soil layer: non-displacement piles, partially displacement piles, and fully displacement piles. Among them, displacement piles have high single pile bearing capacity, can save a lot of building materials, and have a fast construction speed, thus saving construction time, and are therefore widely used.

[0003] Currently, spiral displacement piles include bidirectional spiral displacement piles and screw piles. Spiral displacement piles are a construction technique that uses a high-torque power head to drive a drill bit to rotate and squeeze or partially squeeze soil to form a hole for concrete injection, followed by the insertion of a reinforcing cage to form the pile. The advantages of this construction technique are: no mud is produced, and the amount of excavated soil is very small, making it relatively environmentally friendly.

[0004] For example, Chinese patent CN106638580B discloses a method for pile formation using a spiral soil displacement drilling casing followed by concrete pouring. This method includes a power head 1 and a power head 2 installed on a spiral soil displacement pile driver. The power head 2 is a hollow structure with a casing connected to it via a reverse spiral. The power head 2 is fitted outside the power head 1. The method involves starting the power head 1 to rotate clockwise and drill downwards to form a hole, then starting the power head 2 until both the drill bit of the power head 1 and the casing of the power head 2 have reached the designed depth, at which point drilling stops. A concrete pump is then started to pump concrete into the hole. The power head 1 rotates and is lifted upwards until the concrete pumping volume reaches a certain distance, at which point pumping stops, the power head 2 separates from the casing, and is lifted upwards to a certain height. The reinforcing cage is then lowered to the designed height. Concrete is pumped into the casing. After stopping concrete pumping, the power head 2 is started to rotate and be lifted upwards until the casing is completely removed from the soil layer, thus forming the pile.

[0005] Regarding the aforementioned technologies, the inventors believe that during the process of lowering the existing rebar cage to the designated height inside the casing, the deep pile hole causes the rebar cage to easily sway, affecting the final placement angle of the rebar cage. This often requires multiple adjustments and alignments of the rebar cage after it has been lowered, reducing construction efficiency. Summary of the Invention

[0006] To facilitate the rapid and stable placement of the reinforcing cage, this application provides a method for pile formation using a spiral extrusion casing followed by concrete pouring.

[0007] The spiral extrusion casing method for pile formation followed by concrete pouring provided in this application adopts the following technical solution:

[0008] The method for forming piles by spiral extrusion casing followed by concrete pouring includes the following steps:

[0009] S1) A second power head is provided on the outside of the first power head of the spiral soil displacement pile machine. The second power head is located below the outside of the first power head of the spiral soil displacement pile machine, and the second power head is a hollow structure. Soil displacement drill bits are installed at the lower end of the first power head and the lower end of the second power head.

[0010] S2) A sleeve is sleeved on the outside of the second power head and detachably connected thereto, and a positioning component is movably arranged inside the sleeve;

[0011] S3) After the spiral soil displacement grouting machine is in place, start the first power head to rotate and drill downward to form a hole, and then start the second power head to drive the casing to rotate and drill downward to form a hole until the soil displacement drill bit of the first power head and the casing of the second power head have drilled to the designed depth and then stop drilling.

[0012] S4) Disconnect the second power head from the casing, start the concrete pump connected to the first power head, pump concrete into the borehole and simultaneously lift the first power head and the second power head upwards until the soil-displacing drill bit of the first power head is completely pulled out of the casing.

[0013] S5) The steel cage is locked into the corresponding position of the positioning component by the locking component, and then lowered along the casing to the predetermined height, and concrete is pumped into the casing until the designed pile top elevation is reached;

[0014] S6) Reconnect the second power head to the casing by locking the component, start the second power head to rotate and lift upward until the casing is completely removed from the soil layer to form a pile.

[0015] By adopting the above technical solution, the locking component can lock and limit the rebar cage. With the cooperation of the positioning component, the rebar cage can be lowered more stably along the casing to the designated installation position, which effectively reduces the number of times workers need to correct the position of the rebar cage inside the borehole, thereby improving the efficiency of pile formation. In addition, by connecting the locking component to the second power head, the casing and the second power head can be linked, which facilitates the second power head to drive the casing to drill downwards quickly.

[0016] Preferably, the positioning component includes a fixed limiting ring and a movable limiting ring. The fixed limiting ring is located on the bottom side of the inner sleeve, and the movable limiting ring is movably connected to the inner side of the sleeve and connected to the reinforcing cage through a locking component.

[0017] By adopting the above technical solution, the reinforcing cage can move downward along the casing under the guidance of the dynamic limiting ring, thereby effectively improving the stability of the lowering of the reinforcing cage, reducing the need for workers to make multiple corrections to the position of the reinforcing cage, and improving the efficiency of pile formation.

[0018] Preferably, the locking assembly includes a guide and a locking member. The guide is disposed on the inner ring side of the moving limit ring, and the locking member is slidably disposed on the guide and can be connected to the second power head and the reinforcing cage, respectively.

[0019] By adopting the above technical solution, the longitudinal steel bars of the steel cage are first guided by the guide component, and then the transverse steel bars of the steel cage are limited and abutted by the snap-fit ​​component, thereby realizing the connection between the steel cage and the moving limit ring. The moving limit ring is then used to limit the lowering of the steel cage, thus improving stability.

[0020] Preferably, the bottom of the moving limit ring is provided with a linkage component, and the fixed limit ring is provided with a linkage groove that is connected to the linkage component.

[0021] By adopting the above technical solution, the linkage component can be connected and cooperate with the linkage groove to realize the limitation of the moving limit ring by the fixed limit ring, thereby improving the stability of the steel cage after it is lowered to the designated position.

[0022] Preferably, the guide includes a pressing block and a clamping spring. The pressing block is slidably disposed on the inner wall of the moving limit ring, and the clamping spring is disposed on the pressing block and is used to adjust the pressing force of the pressing block.

[0023] By adopting the above technical solution, the clamping spring can make the clamping block stably abut against the longitudinal steel bars of the steel cage, thereby better improving the guidance and limiting of the steel cage.

[0024] Preferably, the snap-fit ​​component includes an adjusting ring and a pressure block, the pressure block being slidably connected to the abutment block, and the adjusting ring having an inclined groove on its inner side, the inclined groove being slidably connected to the pressure block.

[0025] By adopting the above technical solution, the position of the pressure block is adjusted by rotating the adjusting ring and then by adjusting the inclined groove, thereby quickly clamping and limiting the transverse steel bars of the steel cage, thus achieving rapid locking and limiting of the steel cage and improving the stability of the steel cage during lowering.

[0026] Preferably, after the first power head is started, it rotates in the forward direction to drill downwards, and after the second power head is started, it drives the casing to rotate in the reverse direction and follow downwards.

[0027] By adopting the above technical solution, it is easier for the first and second power heads to drill downwards, thereby increasing the drilling speed and obtaining better-formed holes.

[0028] Preferably, after pumping concrete into the casing until the top of the concrete surface is above the midpoint of the reinforcing cage, the second power head is reconnected to the casing via the locking assembly. The second power head is then started to rotate and lifted upwards to remove it. Concrete is then pumped into the hole until it covers the reinforcing cage, thus forming a pile.

[0029] By adopting the above technical solution, the casing can be easily removed while the pile forming quality can be improved more effectively.

[0030] In summary, this application includes at least one of the following beneficial technical effects:

[0031] 1. The locking component can lock and limit the rebar cage. With the cooperation of the positioning component, the rebar cage can be lowered more stably along the casing to the designated installation position, which can effectively reduce the number of times the worker corrects the position of the rebar cage inside the borehole, thereby improving the efficiency of pile formation. In addition, by connecting the locking component to the second power head, the casing and the second power head can be linked, which makes it easier for the second power head to drive the casing to drill downwards quickly.

[0032] 2. The longitudinal reinforcement bars of the steel cage are first guided by the guide component, and then the transverse reinforcement bars of the steel cage are limited and abutted by the snap-fit ​​component, thereby realizing the connection between the steel cage and the moving limit ring. The moving limit ring is then used to limit the lowering of the steel cage, which improves stability.

[0033] 3. By first starting the first power head and rotating it forward to drill downwards, and then starting the second power head to drive the casing to rotate in the opposite direction and follow, it is easier for the first and second power heads to drill downwards, thereby increasing the drilling speed and obtaining a better-formed hole. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the overall structure of the spiral soil displacement grouting pile machine according to an embodiment of this application;

[0035] Figure 2 This is a schematic diagram of the overall internal structure of the sleeve in an embodiment of this application;

[0036] Figure 3 This is a schematic diagram of the internal structure of the steel cage and the sleeve after they are connected in an embodiment of this application;

[0037] Figure 4 yes Figure 2 Enlarged view of section A;

[0038] Figure 5 This is a schematic diagram of the structure of the clamping block and the pressing block in an embodiment of this application;

[0039] Figure 6 This is a schematic diagram of the fixed limit ring and the moving limit ring in an embodiment of this application.

[0040] Explanation of reference numerals in the attached figures:

[0041] 1. First power head; 2. Second power head; 3. Soil-displacing drill bit; 4. Casing; 5. Positioning assembly; 51. Fixed limit ring; 511. Linkage groove; 52. Moving limit ring; 6. Reinforcing cage; 7. Locking assembly; 71. Guide; 711. Clamping block; 712. Clamping spring; 72. Snap-fit ​​component; 721. Adjusting ring; 722. Pressure block; 723. Inclined groove; 8. Linkage assembly. Detailed Implementation

[0042] The following is in conjunction with the appendix Figure 1-6 This application will be described in further detail.

[0043] Example:

[0044] This application discloses a method for pile formation using a spiral extrusion casing followed by concrete pouring, referring to... Figure 1-3 The method of forming piles by spiral extrusion casing followed by concrete pouring includes the following steps:

[0045] S1) A second power head 2 is installed on the outside of the first power head 1 on the spiral soil displacement pile machine. The second power head 2 is located below the outside of the first power head 1 of the spiral soil displacement pile machine. The second power head 2 is a hollow structure and the first power head 1 is cylindrical and penetrates the second power head 2. Soil displacement drill bits 3 are installed at the lower end of the first power head 1 and the lower end of the second power head 2.

[0046] S2) A sleeve 4 is sleeved on the outside of the second power head 2 and detachably connected to the locking component 7, and a positioning component 5 is slidably connected inside the sleeve 4;

[0047] S3) After the spiral soil squeezing and grouting pile machine is in place, start the first power head 1 to rotate forward and drill downward to form a hole. Then start the second power head 2 to drive the casing 4 to rotate in the opposite direction and drill downward to form a hole. Stop drilling when the soil squeezing drill bit 3 of the first power head 1 and the casing 4 of the second power head 2 have drilled to the designed depth.

[0048] S4) Unlock the connection between the locking component 7 and the second power head 2 and the casing 4, then start the concrete pump connected to the first power head 1, pump concrete into the borehole and lift the first power head 1 and the second power head 2 upwards until the soil squeezing drill bit 3 of the first power head 1 is completely pulled out of the casing 4.

[0049] S5) The steel cage 6 is locked into the corresponding position of the positioning component 5 by the locking component 7, and then lowered along the extension direction of the sleeve 4, so that the linkage component 8 at the bottom of the moving limit ring 52 is connected and cooperated with the linkage groove 511 at the top of the fixed limit ring 51, and concrete is pumped into the sleeve 4 until the height of the top surface of the concrete exceeds the midpoint of the steel cage 6.

[0050] S6) Then, reconnect the second power head 2 and the sleeve 4 through the locking component 7, start the second power head 2 to rotate and lift it up to take it out, and then pump the concrete into the hole until it covers the steel cage 6, and the pile can be formed.

[0051] S7) Move the auger soil displacement pile driver to the next pile location for construction.

[0052] Reference Figure 1-3 In this embodiment, the positioning component 5 includes a fixed limiting ring 51 and a movable limiting ring 52. The fixed limiting ring 51 is fixed to the bottom of the inner side of the sleeve 4, while the movable limiting ring 52 is slidably installed on the inner side of the sleeve 4.

[0053] In addition, in this embodiment, the locking component 7 includes a guide 71 and a latching member 72. Multiple guides 71 are arranged in a circular array and mounted on the inner ring side of the moving limiting ring 52, while the latching member 72 is slidably connected to the top of the guides 71.

[0054] Reference Figure 2 , Figure 4-5 In this embodiment, the guide 71 includes abutment blocks 711 and clamping springs 712. Two abutment blocks 711 are symmetrically arranged and slidably connected to the inner ring wall of the movable limiting ring 52. The inner wall of each abutment block 711 is configured as an arc shape adapted to the shape of the reinforcing bars in the reinforcing cage 6. The clamping springs 712 are installed between the two abutment blocks 711 to continuously pull the two abutment blocks 711 closer together, thereby achieving continuous clamping of the reinforcing cage 6.

[0055] In addition, to connect the second power head 2 to the casing 4, an annular groove is provided on the top circumference of the second power head 2, and a connecting ring is fixed in the annular groove. During connection, the connecting ring can be clamped by multiple snap-fit ​​pieces 72 to achieve the connection between the second power head 2 and the casing 4, thereby achieving the purpose of simultaneous downward drilling of the second power head 2 and the casing 4.

[0056] Furthermore, in this embodiment, the snap-fit ​​component 72 includes an adjusting ring 721 and a pressure block 722. The pressure block 722 is slidably connected to the top of the abutment block 711, and a connecting strip is fixed between the outer surfaces of the two pressure blocks 722. The adjusting ring 721 is rotatably connected to the side of each connecting strip away from the pressure block 722, and an inclined groove 723 is formed on the inner ring wall of the adjusting ring 721, which slidably connects to the protrusion on the back of the connecting strip. By rotating the adjusting ring 721, the inclined groove 723 allows each set of pressure blocks 722 corresponding to multiple connecting strips to simultaneously move closer to the reinforcing cage 6 or the connecting ring, thereby achieving connection limiting of the reinforcing cage 6 or the second power head 2 according to the actual operation steps.

[0057] Reference Figure 3-5 A through locking groove is provided at the top of the adjusting ring 721 and at the position corresponding to the inclined groove 723. A locking bolt is slidably provided in the locking groove. The locking bolt passes through the through locking groove and is threadedly connected to the protrusion inside the inclined groove 723, thereby realizing the common limiting of the same set of pressure blocks 722 and further improving the clamping and locking of the steel cage 6 or the second power head 2.

[0058] In addition, to facilitate the downward drilling of the casing 4, threads are provided on the outer wall of the casing 4. This allows the casing 4 to be easily buried in the ground or removed from the ground.

[0059] In addition, refer to Figure 3 and Figure 6 In this embodiment, the linkage component 8 includes four extension strips evenly fixed to the bottom of the moving limiting ring 52, and four linkage grooves 511 are provided on the top of the fixed limiting ring 51 corresponding to the positions of the four extension strips. When the moving limiting ring 52 moves down to the bottom of the sleeve 4, the extension strips can slide into the interior of the linkage grooves 511, realizing the connection between the moving limiting ring 52 and the fixed limiting ring 51, thereby further improving the connection stability between the rebar cage 6 or the second power head 2 and the sleeve 4.

[0060] The implementation principle of the spiral soil squeezing hole forming and fixing sleeve 4 followed by concrete pouring pile forming method in this application embodiment is as follows: by setting a dynamic limiting ring 52 and a fixed limiting ring 51 on the inner side of the sleeve 4 respectively, and by using the guide 71 and the snap-fit ​​72 to tightly connect the steel cage 6, the steel cage 6 can be quickly limited and lowered, that is, installed in the center; when pouring concrete, it is necessary to pour half of the concrete first to initially fix the steel cage 6, and then take out the sleeve 4 and continue to pump concrete into the borehole until the concrete covers the steel cage 6 to form a pile.

[0061] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A method for forming piles by spiral extrusion drilling casing followed by concrete pouring, characterized in that: Includes the following steps: S1) A second power head (2) is provided on the outside of the first power head (1) of the spiral soil squeezing pile machine. The second power head (2) is located below the outside of the first power head (1) of the spiral soil squeezing pile machine, and the second power head (2) is a hollow structure. Soil squeezing drill bit (3) is installed at the lower end of the first power head (1) and the lower end of the second power head (2). S2) A sleeve (4) is sleeved and detachably connected to the outside of the second power head (2), and a positioning component (5) is movably arranged inside the sleeve (4). S3) After the spiral soil squeezing and grouting pile machine is in place, start the first power head (1) to rotate and drill downward to form a hole, and then start the second power head (2) to drive the casing (4) to rotate and drill downward to form a hole until the soil squeezing drill bit (3) of the first power head (1) and the casing (4) of the second power head (2) have drilled to the designed depth and then stop drilling. S4) Disconnect the second power head (2) from the casing (4), start the concrete pump connected to the first power head (1), pump concrete into the borehole and lift the first power head (1) and the second power head (2) upwards until the soil squeezing drill bit (3) of the first power head (1) is completely pulled out of the casing (4). S5) The steel cage (6) is inserted into the corresponding position of the positioning component (5) by locking component (7), and then lowered along the sleeve (4) to the predetermined height, and concrete is pumped into the sleeve (4) until the designed pile top elevation is reached; S6) Reconnect the second power head (2) and the casing (4) by locking component (7), start the second power head (2) to rotate and lift upward until the casing (4) is completely removed from the soil layer to form a pile; The positioning component (5) includes a fixed limiting ring (51) and a movable limiting ring (52). The fixed limiting ring (51) is located on the inner bottom side of the sleeve (4), and the movable limiting ring (52) is movably connected to the inner side of the sleeve (4) and connected to the reinforcing cage (6) through the locking component (7). The bottom of the moving limit ring (52) is provided with a linkage component (8), and the fixed limit ring (51) is provided with a linkage groove (511) connected to the linkage component (8).

2. The method for forming piles by spiral soil displacement casing followed by concrete pouring according to claim 1, characterized in that: The locking component (7) includes a guide (71) and a snap-fit ​​component (72). The guide (71) is disposed on the inner ring side of the moving limit ring (52). The snap-fit ​​component (72) is slidably disposed on the guide (71) and can be connected to the second power head (2) and the steel cage (6) respectively.

3. The method for forming piles by spiral soil displacement casing followed by concrete pouring according to claim 2, characterized in that: The guide (71) includes a pressing block (711) and a clamping spring (712). The pressing block (711) is slidably disposed on the inner wall of the moving limit ring (52). The clamping spring (712) is disposed on the pressing block (711) and is used to adjust the pressing force of the pressing block (711).

4. The method for forming piles by spiral soil displacement casing followed by concrete pouring according to claim 3, characterized in that: The snap-fit ​​component (72) includes an adjusting ring (721) and a pressure block (722). The pressure block (722) is slidably connected to the abutment block (711). An inclined groove (723) is provided on the inner side of the adjusting ring (721). The inclined groove (723) is slidably connected to the pressure block (722).

5. The method for forming piles by spiral soil displacement casing followed by concrete pouring according to claim 1, characterized in that: After the first power head (1) is started, it rotates in the forward direction to drill downwards and form a hole, and after the second power head (2) is started, it drives the casing (4) to rotate in the reverse direction and follow downwards.

6. The method for forming piles by spiral soil displacement casing followed by concrete pouring according to claim 1, characterized in that: After pumping concrete into the casing (4) until the top of the concrete is above the midpoint of the reinforcing cage (6), the second power head (2) is reconnected to the casing (4) through the locking component (7). The second power head (2) is started to rotate and lifted upwards to remove the concrete. Then, the concrete is pumped into the hole until it is above the reinforcing cage (6) to form a pile.

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