Improved precast pile for collapsible loess area and construction technology

Abstract

The invention relates to the technical field of building pipe piles, in particular to an improved precast pile in a collapsible loess area and a construction technology, the improved precast pile comprises a hollow steel pipe pile, and a receding hole is formed in the hollow steel pipe pile; the at least one guide insertion strip is rotationally connected with the hollow steel pipe pile, the rotating plane of the guide insertion strip is vertically arranged, the guide insertion strip extends into an inner cavity of the hollow steel pipe pile through the receding hole to form a linkage strip, the guide insertion strip and the linkage strip are both arranged in a hollow mode, and a plurality of grout outlets are formed in the guide insertion strip; an inner cavity of the hollow steel pipe pile communicates with the grout outlet through an inner cavity of the linkage strip. The rotation driving unit is movably arranged in an inner cavity of the hollow steel pipe pile, and the rotation driving unit is matched with the linkage strip to drive the guide insertion strip to rotate; the precast pile has the effects that the strengthening effect of the under-pressure concrete on the soil body around the precast pile is improved, and then the settlement amount of the precast pile is reduced when collapsible settlement occurs in the soil body.

Description

Technical Field

[0001] The present application relates to the technical field of building pipe piles, and in particular to an improved prefabricated pile and a construction process in collapsible loess areas. Background Art

[0002] A foundation reinforcement pile is a civil engineering structure used to enhance soil bearing capacity and stability; it is usually made of concrete, steel or other materials, is driven deep into the ground and tightly integrated with the surrounding soil; the main purpose of a foundation reinforcement pile is to increase the bearing capacity of the foundation by increasing the bearing area of ​​the foundation and improving the physical properties of the soil, thereby ensuring the stability and safety of the building.

[0003] The prior art discloses a base-enlarged pile for pre-watering and compacting collapsible loess, which comprises a precast concrete pipe pile, a conical head is formed at the bottom of the precast concrete pipe pile, a detachable lower sealing structure is installed on the top of the conical head, and a detachable upper sealing structure is installed in the precast concrete pipe pile; a cavity is formed in the conical head, and a plurality of pile end immersion ports connected to the cavity are formed on the surface of the conical head; a plurality of pile side immersion ports are formed in sequence from top to bottom in the circumference of the precast concrete pipe pile; an upper water injection cavity is formed between the detachable lower sealing structure and the detachable upper sealing structure; the cavity of the conical head is connected to a pile end water inlet pipe, and the upper water injection cavity is connected to a pile side water inlet pipe; and a pile side immersion port is formed on the side of the precast concrete pipe pile.

[0004] With regard to the above-mentioned related technologies, after the precast piles are inserted into the foundation, concrete is injected into the inner cavity of the precast piles under pressure so that the concrete diffuses into the collapsible soil around the precast piles, thereby forming a structural reinforcement for the collapsible soil. However, due to the obstruction of the soil, the concrete can only be reinforced in the area relatively close to the precast piles, and the soil reinforcement effect is poor, resulting in more obvious settlement of the precast piles when collapsible settlement of the soil occurs. Summary of the invention

[0005] In order to improve the reinforcing effect of pressurized concrete on the soil around precast piles and thereby reduce the settlement of precast piles when collapsible settlement of the soil occurs, the present application provides an improved precast pile and construction process for collapsible loess areas.

[0006] The improved prefabricated pile and construction process for collapsible loess areas provided in this application adopt the following technical solutions: In a first aspect, the present application provides an improved prefabricated pile for collapsible loess areas.

[0007] An improved prefabricated pile for collapsible loess areas, comprising: A hollow steel pipe pile with a pile tip, wherein at least one clearance hole is formed on the hollow steel pipe pile; At least one guide insertion bar, the guide insertion bar is rotatably connected to the hollow steel pipe pile, and the rotation plane of the guide insertion bar is vertically arranged, the guide insertion bar extends into the inner cavity of the hollow steel pipe pile through the clearance hole to form a linkage bar, and the guide insertion bar and the linkage bar are both hollow, and a plurality of slurry outlets are opened on the guide insertion bar, and the inner cavity of the hollow steel pipe pile is connected to the slurry outlets through the inner cavity of the linkage bar; A rotation driving unit is movably arranged in the inner cavity of the hollow steel pipe pile, and the rotation driving unit cooperates with the linkage bar to drive the guide insertion bar to rotate.

[0008] By adopting the above technical scheme, pile foundation holes are constructed at designated locations, and then hollow steel pipe piles are sunk into the pile foundation holes; after the hollow steel pipe piles reach the target location, grouting is performed under pressure into the inner cavity of the hollow steel pipe piles, so that the rotation drive unit is activated and force is applied to the linkage bar, and the linkage bar drives the guide insertion bar to rotate while the guide insertion bar is activated, until the guide insertion bar is rotated into place, and the concrete in the hollow steel pipe piles penetrates into the soil around the piles through the clearance holes, and penetrates into the soil around the guide insertion bar from the slurry outlet through the linkage bar and the inner cavity of the guide insertion bar, thereby completing soil reinforcement; the designed improved prefabricated piles in collapsible loess areas can provide a supporting foundation for ground buildings through the hollow steel pipe piles, and can provide a support for the rotation of the guide insertion bar and the linkage bar through the clearance holes The guide bar can be used to make way, so that the linkage bar can be rotated to a state of being in contact with the inner wall of the hollow steel pipe pile, and the making way hole can be used as a discharge outlet for concrete on the hollow steel pipe pile. Firstly, the guide insertion bar can provide a guiding effect for the hollow steel pipe column during the sinking of the hollow steel pipe pile. Secondly, the guide insertion bar can be extended into the soil around the hollow steel pipe pile to form a structure similar to an "anchor cable", which is convenient for concrete to penetrate into the area far away from the pile, so as to improve the overall strengthening effect of the soil, and then reduce the settlement of the precast pile when the soil undergoes collapsible settlement. The guide insertion bar can be driven to rotate by the rotating drive unit, so that the guide insertion bar is changed from a state of being in contact with the hollow steel pipe column to a horizontal state, and is extended into the soil around the pile.

[0009] In a specific possible implementation scheme, at least one slurry discharge port is provided on the hollow steel pipe pile, and the guide insertion strip blocks the slurry discharge port when the pile is in the pile sinking state.

[0010] By adopting the above technical solution and designing the slurry discharge port, the possibility of mud or water in the soil entering the inner cavity of the hollow steel pipe pile during the sinking of the hollow steel pipe pile can be reduced.

[0011] In a specific embodiment, the rotation drive unit includes: A driving block, wherein the driving block is located in the inner cavity of the hollow steel pipe pile and a sliding gap is left between the driving block and the inner cavity of the hollow steel pipe pile, and when the linkage bar is rotated to be in contact with the inner wall of the hollow steel pipe pile, the thickness of the linkage bar is smaller than the sliding gap; A reserved grouting pipe is connected to the hollow steel pipe pile, the driving block is slidably connected to the reserved grouting pipe, and the grout outlet of the reserved grouting pipe is located below the driving block.

[0012] By adopting the above technical solution, a rotating drive unit is designed. After the hollow steel pipe pile sinks into place, during the period of injecting concrete under pressure into the hollow steel pipe column through the reserved grouting pipe, the thrust of the concrete on the drive block is utilized to make the drive block float up along the axial direction of the hollow steel pipe pile and push the linkage bar to rotate around the rotation point, thereby realizing the rotation of the guide insertion bar, and the drive block itself can also form a certain pressure for the concrete injection.

[0013] In a specific possible implementation scheme, it also includes a plurality of columnar reinforcing steel bars, the axial direction of the plurality of columnar reinforcing steel bars is consistent with the axial direction of the hollow steel pipe pile, the columnar reinforcing steel bars are connected to the hollow steel pipe pile, the columnar reinforcing steel bars are arranged through the driving block, and the driving block is slidingly connected to the columnar reinforcing steel bars.

[0014] By adopting the above technical solution, the designed columnar reinforcement steel bars can improve the structural strength of the concrete in the hollow steel pipe pile.

[0015] In a specific possible implementation manner, a counterweight portion is connected to the driving block.

[0016] By adopting the above technical solution, by changing the weight of the counterweight part, the relationship between the concrete injection pressure and the floating speed of the driving block can be changed, and the concrete injection pressure can also be increased to facilitate the concrete to penetrate into the soil around the pile or penetrate into the soil through the slurry outlet.

[0017] In a specific possible implementation manner, the thickness of the guide insertion strip gradually increases toward a side close to the hollow steel pipe pile.

[0018] By adopting the above technical solution, the guide insertion strip with a gradually changing thickness is designed, which can reduce the resistance of breaking the ground during rotation.

[0019] In a second aspect, the present application provides a construction process for improved precast piles in collapsible loess areas.

[0020] A construction process for improved prefabricated piles in collapsible loess areas, comprising: Carry out pile foundation hole construction at the designated location, and then sink the hollow steel pipe pile into the pile foundation hole; After the hollow steel pipe pile reaches the target position, grouting is injected under pressure into the inner cavity of the hollow steel pipe pile, so that the rotation drive unit is activated and force is applied to the linkage bar. The linkage bar drives the guide insertion bar to rotate at the same time until the guide insertion bar is rotated into place. The concrete in the hollow steel pipe pile penetrates into the soil around the pile through the clearance hole, and penetrates into the soil around the guide insertion bar from the grouting port through the linkage bar and the inner cavity of the guide insertion bar, thereby completing soil reinforcement.

[0021] By adopting the above technical scheme, the hollow steel pipe piles can provide a supporting foundation for the ground buildings, and the clearance holes can provide clearance for the guide insertion strips and the linkage strips to rotate, so as to facilitate the linkage strips to rotate to a state of being in contact with the inner wall of the hollow steel pipe piles, and the clearance holes can be used as a discharge outlet for the concrete on the hollow steel pipe piles. Firstly, the guide insertion strips can provide guidance for the hollow steel pipe columns during the sinking of the hollow steel pipe piles. Secondly, the guide insertion strips can be extended into the soil around the hollow steel pipe piles to form a structure similar to an "anchor cable", which is convenient for concrete to penetrate into the area far away from the piles, so as to improve the overall strengthening effect of the soil, and then reduce the settlement of the precast piles when the soil undergoes collapsible settlement. The rotation of the guide insertion strips can be driven by the rotating drive unit, so that the guide insertion strips are changed from a state of being in contact with the hollow steel pipe column to a horizontal state, and are extended into the soil around the piles.

[0022] In a specific embodiment, the rotation drive unit includes: The driving block is located in the inner cavity of the hollow steel pipe pile, and a sliding gap is left between the driving block and the inner cavity of the hollow steel pipe pile. When the linkage bar rotates to be in contact with the inner wall of the hollow steel pipe pile, the thickness of the linkage bar is smaller than the sliding gap. A grouting pipe is reserved, the grouting pipe is connected to the hollow steel pipe pile, the driving block is slidably connected to the grouting pipe, and the grouting outlet of the grouting pipe is located below the driving block; The external pressure grouting equipment injects grout into the inner cavity of the hollow steel pipe pile through the reserved grouting pipe. The concrete slurry seeps out from the concession hole to the soil around the pile, while the driving block rises along the axial direction of the hollow steel pipe pile and pushes the linkage bar to rotate until the linkage bar is in contact with the inner wall of the hollow steel pipe column. At this time, the guide insertion bar rotates toward the side away from the hollow steel pipe pile under the drive of the linkage bar until the concrete penetrates into the soil through the linkage bar and the inner cavity of the guide insertion bar through the slurry outlet to complete the reinforcement.

[0023] By adopting the above technical solution, after the hollow steel pipe pile sinks into place, during the process of injecting concrete under pressure into the hollow steel pipe column through the reserved grouting pipe, the thrust of the concrete on the driving block is utilized to enable the driving block to float up along the axial direction of the hollow steel pipe pile and push the linkage bar to rotate around the rotation point, thereby realizing the rotation of the guide insertion bar, and the driving block itself can also form a certain pressure for the concrete injection.

[0024] In a specific feasible implementation scheme, during the process of grouting into the inner cavity of the hollow steel pipe pile through the reserved grouting pipe, the grouting pressure and the floating speed of the driving block are observed, and stones are thrown from the pile mouth of the hollow steel pipe pile to accumulate on the top wall of the driving block to form a counterweight portion.

[0025] By adopting the above technical solution, by changing the weight of the counterweight part, the relationship between the concrete injection pressure and the floating speed of the driving block can be changed, and the concrete injection pressure can also be increased to facilitate the concrete to penetrate into the soil around the pile or penetrate into the soil through the slurry outlet.

[0026] In summary, the present application includes at least one of the following beneficial technical effects: 1. The improved prefabricated piles designed for collapsible loess areas can provide a supporting foundation for ground buildings through hollow steel pipe piles, and can provide a clearance for the rotation of the guide insertion strip and the linkage strip through the clearance hole, so as to facilitate the linkage strip to rotate to a state of being in contact with the inner wall of the hollow steel pipe pile, and the clearance hole can be used as a discharge outlet for concrete on the hollow steel pipe pile. First, the guide insertion strip can provide a guiding effect for the hollow steel pipe column during the sinking of the hollow steel pipe pile. Secondly, the guide insertion strip can be extended into the soil around the hollow steel pipe pile to form a structure similar to an "anchor cable", which is convenient for concrete to penetrate into the area far away from the pile, so as to improve the overall strengthening effect of the soil, and then reduce the settlement of the prefabricated pile when the soil undergoes collapsible settlement. The rotation of the guide insertion strip can be driven by the rotation drive unit, so that the guide insertion strip is changed from a state of being in contact with the hollow steel pipe column to a horizontal state, and is extended into the soil around the pile.

[0027] 2. The improved precast pile designed for collapsible loess areas, after the hollow steel pipe pile sinks into place, during the period of injecting concrete under pressure into the hollow steel pipe column through the reserved grouting pipe, the thrust of the concrete on the driving block is used to make the driving block float up along the axial direction of the hollow steel pipe pile, and push the linkage bar to rotate around the rotation point, thereby realizing the rotation of the guide insertion bar, and the driving block itself can also form a certain pressure for concrete injection.

[0028] 3. The improved precast pile designed for collapsible loess areas can change the relationship between the concrete injection pressure and the floating speed of the driving block by changing the weight of the counterweight part, and can also increase the concrete injection pressure to facilitate the concrete to penetrate into the soil around the pile or penetrate into the soil through the slurry outlet. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the structure of the improved prefabricated piles in the collapsible loess area according to the embodiment of the present application.

[0030] Figure 2 yes Figure 2 Schematic diagram of the three-dimensional structure.

[0031] Figure 3 yes Figure 2 Sectional view in .

[0032] Figure 4 yes Figure 3 Cross-sectional view of the middle guide insert after it is rotated to the working state.

[0033] Explanation of the reference numerals: 1. hollow steel pipe pile; 11. clearance hole; 12. slurry discharge port; 2. guide insertion strip; 21. slurry outlet; 3. linkage strip; 4. rotation drive unit; 41. drive block; 42. reserved grouting pipe; 5. columnar reinforcement steel bar; 6. counterweight part. DETAILED DESCRIPTION

[0034] The following is combined with Figure 1-4 This application is described in further detail.

[0035] The embodiments of the present application disclose an improved prefabricated pile and a construction process for collapsible loess areas.

[0036] In a first aspect, an embodiment of the present application discloses an improved prefabricated pile for collapsible loess areas.

[0037] Reference Figure 1 The invention discloses an improved prefabricated pile for collapsible loess areas, comprising a hollow steel pipe pile 1 and at least one guide insertion strip 2. The hollow steel pipe column is hollow, and one end of the hollow steel pipe pile 1 forms a pile tip so as to break through the soil and sink. The hollow steel pipe pile 1 is provided with at least one clearance hole 11. The guide insertion strip 2 is rotatably connected to the hollow steel pipe pile 1, and the rotation connection point between the guide insertion strip 2 and the hollow steel pipe pile 1 is arranged close to the clearance hole 11. The rotation plane of the guide insertion strip 2 is vertically arranged and passes through the axis of the hollow steel pipe column. The guide insertion strip 2 is arranged through the hollow steel pipe column. A linkage bar 3 is formed by extending the clearance hole 11 into the hollow steel pipe pile 1. The linkage bar 3 is integrally connected with the guide insertion bar 2, and the guide insertion bar 2 and the linkage bar 3 are both hollow. The guide insertion bar 2 is rotatably connected to the hollow steel pipe pile 1 through the linkage bar 3. A plurality of slurry outlets 21 are provided on the guide insertion bar 2. The inner cavity of the hollow steel pipe pile 1 is connected with the slurry outlet 21 via the inner cavity of the linkage bar 3 and the inner cavity of the guide insertion bar 2. During the sinking process of the hollow steel pipe pile 1, the guide insertion bar 2 is in contact with the outer wall of the hollow steel pipe pile 1, and the linkage bar 3 remains in a horizontal state.

[0038] Reference Figure 2In order to be able to drive the guide insertion bar 2 to rotate and insert it into the soil after the hollow steel pipe pile 1 sinks into place, the improved prefabricated pile in the collapsible loess area also includes a rotation drive unit 4, which is movably connected to the inner cavity of the hollow steel pipe pile 1, and the movable structure in the rotation drive unit 4 can cooperate with the linkage bar 3 after the axial movement of the hollow steel pipe pile 1, so that the guide insertion bar 2 rotates. After the hollow steel pipe pile 1 sinks into place, the rotation drive unit 4 applies force to the linkage bar 3 to drive the guide insertion bar 2 to rotate until the linkage bar 3 is in contact with the inner wall of the hollow steel pipe pile 1, and the guide insertion bar 2 rotates to a horizontal state.

[0039] Reference Figure 2 The rotation driving unit 4 includes a driving block 41 and a reserved grouting pipe 42. The driving block 41 is located in the inner cavity of the hollow steel pipe pile 1, and a sliding gap is left between the driving block 41 and the inner wall of the hollow steel pipe pile 1. When the linkage bar 3 is in contact with the inner wall of the hollow steel pipe pile 1, the thickness of the linkage bar 3 is smaller than the sliding gap so that the driving block 41 can continue to rise along the axial direction of the hollow steel pipe pile 1 over the linkage bar 3; the reserved grouting pipe 42 is welded and fixed to the hollow steel pipe pile 1, the driving block 41 is slidably connected with the reserved grouting pipe 42, and the grouting outlet 21 of the reserved grouting pipe 42 is located below the driving block 41. The external grouting equipment injects concrete into the inner cavity of the hollow steel pipe pile 1 through the reserved grouting pipe 42. The concrete pushes the driving block 41 to rise while filling the inner cavity of the hollow steel pipe pile 1, and then pushes the linkage bar 3 to rotate through the driving block 41.

[0040] Reference Figure 2 In order to improve the structural strength after pouring concrete into the inner cavity of the hollow steel pipe pile 1, the improved prefabricated pile in the collapsible loess area also includes a plurality of columnar reinforcing steel bars 5, which are welded and fixed to the hollow steel pipe pile 1, and the axial direction of the plurality of columnar reinforcing steel bars 5 is consistent with the axial direction of the hollow steel pipe pile 1, and the columnar reinforcing steel bars 5 are arranged through the driving block 41, and the driving block 41 is slidably connected to the columnar reinforcing steel bars 5.

[0041] Reference Figure 2 In order to control the floating speed of the driving block 41 and thereby ensure the speed and depth of concrete penetrating into the soil, a counterweight part 6 is connected to the driving block 41. The counterweight part 6 can be fixedly connected to the driving block 41 at the initial design stage, or can be temporarily configured later according to the floating speed of the driving block 41.

[0042] Reference Figure 2 In order to reduce the ground-breaking rotation resistance of the conductor insertion bar, the thickness of the guide insertion bar 2 gradually increases toward the side close to the hollow steel pipe pile 1, taking the time when the guide insertion bar 2 is in contact with the outer wall of the hollow steel pipe pile 1 as the description reference.

[0043] Reference Figure 2In order to increase the seepage efficiency of concrete in the hollow steel pipe pile 1, at least one slurry discharge port 12 is opened on the hollow steel pipe pile 1. The slurry discharge port 12 and the clearance hole 11 serve as a concrete seepage window. In order to reduce the possibility of infiltration of surrounding soil or water during the sinking of the hollow steel pipe pile 1, the guide insertion strip 2 is attached to the hollow steel pipe pile 1 during the pile sinking, and the slurry discharge port 12 is blocked at the same time.

[0044] The implementation principle of the improved prefabricated pile in a collapsible loess area according to an embodiment of the present application is as follows: construct a pile foundation hole at a designated location, and then sink the hollow steel pipe pile 1 into the pile foundation hole; after the hollow steel pipe pile 1 is sunk into place, during the period of injecting concrete under pressure into the hollow steel pipe column through the reserved grouting pipe 42, the thrust of the concrete on the driving block 41 is utilized to enable the driving block 41 to float upward along the axial direction of the hollow steel pipe pile 1, and to push the linkage bar 3 to rotate around the rotation point, thereby realizing the rotation of the guide insertion bar 2, until the guide insertion bar 2 is rotated into place, and the concrete in the hollow steel pipe pile 1 penetrates into the soil around the pile through the clearance hole 11, and penetrates into the soil around the guide insertion bar 2 from the slurry outlet 21 through the linkage bar 3 and the inner cavity of the guide insertion bar 2, thereby completing the soil reinforcement.

[0045] In a second aspect, an embodiment of the present application discloses a construction process for improved precast piles in collapsible loess areas.

[0046] Reference Figure 1-Figure 4 A construction process of an improved prefabricated pile in a collapsible loess region, using the improved prefabricated pile in a collapsible loess region disclosed in the first aspect of the embodiment of the present application, comprising: S1: constructing a pile foundation hole at a designated location, and then sinking a hollow steel pipe pile 1 into the pile foundation hole; S2: After the hollow steel pipe pile 1 reaches the target position, grouting is performed under pressure into the inner cavity of the hollow steel pipe pile 1, so that the rotation drive unit 4 is activated and applies force to the linkage bar 3. The linkage bar 3 drives the guide insertion bar 2 to rotate while the linkage bar 3 is activated, until the guide insertion bar 2 is rotated into place, and the concrete in the hollow steel pipe pile 1 penetrates into the soil around the pile through the clearance hole 11, and penetrates into the soil around the guide insertion bar 2 from the grout outlet 21 through the linkage bar 3 and the inner cavity of the guide insertion bar 2, thereby completing soil reinforcement.

[0047] The hollow steel pipe pile 1 can provide a supporting foundation for the ground building, and the clearance hole 11 can provide clearance for the guide insertion strip 2 and the linkage strip 3 to rotate, so as to facilitate the linkage strip 3 to rotate to a state of being in contact with the inner wall of the hollow steel pipe pile 1, and the clearance hole 11 can be used as a discharge outlet for the concrete on the hollow steel pipe pile 1. Firstly, the guide insertion strip 2 can provide a guiding effect for the hollow steel pipe column during the sinking of the hollow steel pipe pile 1. Secondly, the guide insertion strip 2 can be extended into the soil around the hollow steel pipe pile 1 to form a structure similar to an "anchor cable", which is convenient for concrete to penetrate into the area far away from the pile, so as to improve the overall strengthening effect of the soil, and then reduce the settlement of the precast pile when the soil undergoes collapsible settlement. The rotation of the guide insertion strip 2 can be driven by the rotating drive unit 4, so that the guide insertion strip 2 is changed from a state of being in contact with the hollow steel pipe column to a horizontal state, and is extended into the soil around the pile.

[0048] Furthermore, in step S2, the external pressure grouting equipment injects grout into the inner cavity of the hollow steel pipe pile 1 through the reserved grouting pipe 42. The concrete slurry seeps out from the give way hole 11 to the soil around the pile, while the driving block 41 rises axially along the hollow steel pipe pile 1 and pushes the linkage bar 3 to rotate until the linkage bar 3 is in contact with the inner wall of the hollow steel pipe column. At this time, the guide insertion bar 2 rotates toward the side away from the hollow steel pipe pile 1 under the drive of the linkage bar 3, until the concrete penetrates into the soil through the linkage bar 3 and the inner cavity of the guide insertion bar 2 through the slurry outlet 21 to complete the reinforcement.

[0049] After the hollow steel pipe pile 1 sinks into place, while concrete is injected into the hollow steel pipe column under pressure through the reserved grouting pipe 42, the thrust of the concrete on the driving block 41 is utilized to enable the driving block 41 to float upward along the axial direction of the hollow steel pipe pile 1 and push the linkage bar 3 to rotate around the rotation point, thereby realizing the rotation of the guide insertion bar 2, and the driving block 41 itself can also form a certain pressure for the concrete injection.

[0050] Furthermore, during the process of grouting into the inner cavity of the hollow steel pipe pile 1 through the reserved grouting pipe 42, the grouting pressure and the floating speed of the driving block 41 are observed, and stones are thrown from the pile mouth of the hollow steel pipe pile 1 to accumulate on the top wall of the driving block 41 to form a counterweight part 6.

[0051] By changing the weight of the counterweight 6, the relationship between the concrete injection pressure and the floating speed of the driving block 41 can be changed, and the concrete injection pressure can also be increased to facilitate the concrete to penetrate into the soil around the pile or penetrate into the soil through the slurry outlet 21.

[0052] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. An improved prefabricated pile for collapsible loess areas, characterized by: include: A hollow steel pipe pile (1) having a pile tip, wherein at least one clearance hole (11) is provided on the hollow steel pipe pile (1); At least one guide insertion strip (2), the guide insertion strip (2) being rotatably connected to the hollow steel pipe pile (1), and the rotation plane of the guide insertion strip (2) being arranged vertically, the guide insertion strip (2) extending into the inner cavity of the hollow steel pipe pile (1) via the clearance hole (11) to form a linkage strip (3), and the guide insertion strip (2) and the linkage strip (3) are both arranged hollow, and a plurality of slurry outlets (21) are provided on the guide insertion strip (2), and the inner cavity of the hollow steel pipe pile (1) is connected to the slurry outlets (21) via the inner cavity of the linkage strip (3); A rotation drive unit (4), wherein the rotation drive unit (4) is movably arranged in the inner cavity of the hollow steel pipe pile (1), and the rotation drive unit (4) cooperates with the linkage bar (3) to drive the guide insertion bar (2) to rotate.

2. The improved prefabricated pile for collapsible loess areas according to claim 1, characterized in that: At least one slurry discharge opening (12) is provided on the hollow steel pipe pile (1), and the guide insertion strip (2) blocks the slurry discharge opening (12) when the pile is in a pile sinking state.

3. The improved prefabricated pile for collapsible loess areas according to claim 1, characterized in that: The rotation driving unit (4) comprises: A driving block (41), wherein the driving block (41) is located in the inner cavity of the hollow steel pipe pile (1) and a sliding gap is left between the driving block (41) and the inner cavity of the hollow steel pipe pile (1); when the linkage bar (3) rotates to be in contact with the inner wall of the hollow steel pipe pile (1), the thickness of the linkage bar (3) is smaller than the sliding gap; A reserved grouting pipe (42) is connected to the hollow steel pipe pile (1), the driving block (41) is slidably connected to the reserved grouting pipe (42), and the grout outlet (21) of the reserved grouting pipe (42) is located below the driving block (41).

4. The improved prefabricated pile for collapsible loess areas according to claim 3, characterized in that: It also includes a plurality of columnar reinforcing steel bars (5), the axial direction of the plurality of columnar reinforcing steel bars (5) is consistent with the axial direction of the hollow steel pipe pile (1), the columnar reinforcing steel bars (5) are connected to the hollow steel pipe pile (1), the columnar reinforcing steel bars (5) are arranged through the driving block (41), and the driving block (41) is slidably connected to the columnar reinforcing steel bars (5).

5. The improved prefabricated pile for collapsible loess areas according to claim 3, characterized in that: The driving block (41) is connected to a counterweight portion (6).

6. The improved prefabricated pile for collapsible loess areas according to claim 1, characterized in that: The thickness of the guide insertion strip (2) gradually increases towards the side close to the hollow steel pipe pile (1).

7. A construction process for improved prefabricated piles in collapsible loess areas, characterized by: The improved prefabricated pile for collapsible loess areas as claimed in any one of claims 1 to 6 comprises: Carry out pile foundation hole construction at a designated location, and then sink a hollow steel pipe pile (1) into the pile foundation hole; After the hollow steel pipe pile (1) reaches the target position, grouting is injected under pressure into the inner cavity of the hollow steel pipe pile (1), so that the rotation drive unit (4) is activated and applies force to the linkage bar (3). The linkage bar (3) drives the guide insertion bar (2) to rotate at the same time until the guide insertion bar (2) is rotated into place. The concrete in the hollow steel pipe pile (1) penetrates into the soil around the pile through the clearance hole (11), and penetrates into the soil around the guide insertion bar (2) through the linkage bar (3) and the inner cavity of the guide insertion bar (2) from the grout outlet (21), thereby completing soil reinforcement.

8. The construction process of the improved prefabricated pile in collapsible loess area according to claim 7 is characterized by: The rotation driving unit (4) comprises: A driving block (41), the driving block (41) is located in the inner cavity of the hollow steel pipe pile (1), and a sliding gap is left between the driving block (41) and the inner cavity of the hollow steel pipe pile (1); when the linkage bar (3) rotates to be in contact with the inner wall of the hollow steel pipe pile (1), the thickness of the linkage bar (3) is smaller than the sliding gap; A reserved grouting pipe (42) is connected to the hollow steel pipe pile (1), the driving block (41) is slidably connected to the reserved grouting pipe (42), and the grouting outlet (21) of the reserved grouting pipe (42) is located below the driving block (41); The external pressure grouting equipment injects grout into the inner cavity of the hollow steel pipe pile (1) through the reserved grouting pipe (42). The concrete grout seeps out from the clearance hole (11) to the soil around the pile, and at the same time, the driving block (41) rises along the axial direction of the hollow steel pipe pile (1) and pushes the linkage bar (3) to rotate until the linkage bar (3) is in contact with the inner wall of the hollow steel pipe column. At this time, the guide insertion bar (2) is driven by the linkage bar (3) to rotate toward the side away from the hollow steel pipe pile (1) until the concrete penetrates into the soil through the linkage bar (3) and the inner cavity of the guide insertion bar (2) through the grout outlet (21) to complete the reinforcement.

9. The construction process of the improved prefabricated pile in collapsible loess area according to claim 8, characterized in that: During the process of grouting the inner cavity of the hollow steel pipe pile (1) through the reserved grouting pipe (42), the grouting pressure and the floating speed of the driving block (41) are observed, and stones are thrown from the pile mouth of the hollow steel pipe pile (1) to the top wall of the driving block (41) to form a counterweight portion (6).

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