A deep foundation pit support structure and construction method

Abstract

The application relates to a deep foundation pit supporting structure and a construction method, and relates to the field of civil engineering deep foundation pits. The deep foundation pit supporting structure comprises a preset hole formed on a slope, a soil nail inserted into the preset hole, a supporting pipe sleeved with the outer side wall of the soil nail, the supporting pipe comprising a plurality of arc-shaped rods, the plurality of arc-shaped rods being mutually spliced around the circumference of the soil nail, a plurality of connecting components being connected between every two adjacent arc-shaped rods, and a control component connected to the soil nail and used for pushing each arc-shaped rod to move along the radial direction of the soil nail until the arc-shaped rod contacts the inner wall of the preset hole. The application has the effect that the concrete can be better filled in the preset hole.

Description

Technical Field

[0001] This application relates to the field of deep foundation pits in civil engineering, and in particular to a deep foundation pit support structure and construction method. Background Technology

[0002] As my country's urbanization process enters a stage of rapid development, high-rise buildings are springing up everywhere, and the increasing demands for the utilization of underground space are making foundation pits deeper and deeper.

[0003] There are many methods for supporting foundation pit slopes, among which soil nailing is widely used. The soil nailing method requires first drilling pre-drilled holes in the slope, then inserting soil nails into each hole. After the soil nails are inserted, concrete is poured into each hole. Once the concrete has hardened, the soil nails are securely connected to the slope.

[0004] However, after the soil nail is inserted into the pre-drilled hole and before concrete is poured into the hole, soil clods may fall into the hole from the side wall. If concrete is then poured into the hole through the opening, soil clods may obstruct the flow of concrete to the bottom wall of the hole, affecting the filling of the hole. Summary of the Invention

[0005] To facilitate better filling of pre-set holes with concrete, this application provides a deep foundation pit support structure and construction method.

[0006] Firstly, the deep foundation pit support structure provided in this application adopts the following technical solution:

[0007] A deep foundation pit support structure includes a pre-drilled hole in the slope, into which a soil nail is inserted. A support tube is sleeved on the outer wall of the soil nail. The support tube includes multiple arc-shaped rods that are spliced ​​together around the circumference of the soil nail. Multiple connecting components are connected between every two adjacent arc-shaped rods. A control component is connected to the soil nail to push each arc-shaped rod to move radially along the soil nail until the arc-shaped rod contacts the inner wall of the pre-drilled hole.

[0008] By employing the above technical solution, one end of the soil nail is aligned with and inserted into a pre-set hole. Simultaneously, a support tube is inserted into the hole along with the soil nail. Then, a control component pushes each arc-shaped rod radially away from the soil nail until the outer side of each arc-shaped rod is in contact with the sidewall of the pre-set hole. At this point, a gap exists between each arc-shaped rod and the soil nail. During the movement of the arc-shaped rods, adjacent arc-shaped rods gradually separate, while the connecting component always keeps adjacent arc-shaped rods connected. Furthermore, as the arc-shaped rods move away from the soil nail, they can push and crush larger soil clods in the pre-set hole, while smaller protrusions located between adjacent arc-shaped rods do not affect the pouring of concrete into the pre-set hole. Gradually pouring concrete into the gap between the arc-shaped rods and the soil nail facilitates better filling of the pre-set hole.

[0009] Preferably, the connecting assembly includes an elastic connecting rod fixedly connected to one side wall of the arc-shaped rod. Each arc-shaped rod has a transition cavity, a first chamber, and a second chamber in the end opposite to the elastic connecting rod. The transition cavity is located between the first chamber and the second chamber. One side wall of the transition cavity has a first through hole communicating with the first chamber, and the other side wall of the transition cavity has a second through hole communicating with the second chamber. One end of the elastic connecting rod is fixedly connected to a first elastic block and a second elastic block. The diameter of the first elastic block is larger than the diameter of the first through hole and the first elastic block is inserted into the first chamber. The second elastic block is placed in the transition cavity, and the diameter of the second elastic block is larger than the diameter of the second through hole. When adjacent arc-shaped rods move away from each other, the first elastic block disengages from the first chamber, and the second elastic block is inserted into the second chamber.

[0010] By adopting the above technical solution, the support tube is sleeved on the outside of the soil nail. At this time, the first elastic block in each connecting component is inserted into the first chamber, and adjacent arc-shaped rods are locked together. When the support tube is inserted into the preset hole along with the soil nail, the control component pushes the arc-shaped rod to move away from the soil nail. At this time, adjacent arc-shaped rods move away from each other, and the movement of the arc-shaped rods drives the elastic connecting rod to move. The elastic connecting rod pulls the first and second elastic blocks to gradually move away from the first chamber. The first elastic block is squeezed and deformed by the side wall of the first through hole and passes through the first through hole. At this time, the first elastic block is disengaged from the first chamber. When the arc-shaped rod moves to contact the inner wall of the preset hole, the second elastic block is squeezed and deformed by the side wall of the second through hole and passes through the second through hole. At this time, the second elastic block is inserted into the second chamber, and adjacent arc-shaped rods are locked together again. The connecting component connects adjacent arc-shaped rods together and can automatically lock adjacent arc-shaped rods together.

[0011] Preferably, the first elastic block and the second elastic block gradually contract towards each other in a direction that moves away from each other, forming pointed ends.

[0012] By adopting the above technical solution, it is easier for the first elastic block to pass through the first through hole and be inserted into the second chamber, and at the same time, it is easier for the second elastic block to pass through the second through hole and be inserted into the second chamber.

[0013] Preferably, the control component includes a mounting shell with a mounting hole, a guide block fixedly connected to the inner wall of the mounting hole, a guide groove on the side wall of the soil nail, the soil nail being inserted into the mounting hole and the guide block being slidably inserted into the guide groove, the end of the mounting shell near the preset hole being set as a pointed end, a nut being rotatably connected inside the mounting shell, the nut being threadedly connected to the soil nail, a ring of protruding teeth being provided on the outer wall of the nut, a gear being meshed on the protruding teeth, the gear being rotatably connected inside the mounting shell, a drive motor for driving the gear to rotate being connected to the mounting shell, and a limiting component for limiting the rotation of the soil nail being connected to the soil nail.

[0014] By adopting the above technical solution, the drive motor is started, and the output shaft of the drive motor drives the gear to rotate. The rotation of the gear, in turn, drives the screw nut to rotate through the protrusion, and the rotation of the screw nut moves along the length direction of the soil nail. During this process, the guide block moves within the guide groove, which provides guidance for the movement of the mounting shell. As the mounting shell moves closer to the interior of the preset hole, the tip of the mounting shell gradually inserts into the support tube. As the mounting shell enters the support tube, the side wall of the mounting shell pushes the arc-shaped rod to gradually move radially away from the soil nail. Starting the drive motor in reverse allows it to drive the mounting shell to gradually exit the preset hole along the length direction of the soil nail.

[0015] Preferably, the outer wall of the mounting shell is fixedly connected with multiple limiting rods. Each arc-shaped rod has a limiting groove on the inner wall of the end near the bottom wall of the preset hole. When the mounting shell moves along the soil nail to the end of the support tube near the bottom wall of the preset hole, each limiting rod is inserted into the corresponding limiting position.

[0016] By adopting the above technical solution, when the mounting shell moves along the soil nail to the end of the support tube near the bottom wall of the preset hole, each limiting rod is inserted into the corresponding limiting groove. As the mounting shell gradually withdraws from the preset hole, the limiting rod moves relative to the limiting groove until it abuts against the side wall of the limiting groove away from the bottom wall of the preset hole. At this point, the continued movement of the mounting shell drives each arc-shaped rod to move axially along the soil nail until the mounting shell drives the support tube out of the preset hole. During the process of the control component withdrawing from the preset hole, the control component can drive the support tube to gradually detach from the preset hole, making operation simple.

[0017] Preferably, the end of the support tube away from the bottom wall of the preset hole has a flared opening.

[0018] By adopting the above technical solution, it is easy to align the tip of the housing with the flare and insert it into the support tube.

[0019] Preferably, the limiting component includes a limiting plate that is fixedly connected to the end of the soil nail away from the bottom wall of the preset hole by screws, and a plurality of plug-in rods that are plugged into the slope are fixedly connected to the limiting plate. The limiting plate has a plurality of transition holes through which the arc-shaped rods pass.

[0020] By adopting the above technical solution, the limiting plate is fastened to the soil nail with screws, and the plug-in rod is plugged into the slope, which facilitates the restriction of the soil nail from rotating. Furthermore, as the support tube gradually exits the preset hole, one end of each arc-shaped rod gradually inserts into the transition hole, facilitating the smooth exit of the support tube from the preset hole.

[0021] Secondly, the construction method for a deep foundation pit support structure provided in this application adopts the following technical solution:

[0022] A construction method for a deep foundation pit support structure includes the following steps:

[0023] S1. Slope excavation;

[0024] S2. Pre-drill holes on the slope and insert soil nails into each pre-drilled hole;

[0025] S3. Start the drive motor, and the mounting shell pushes each arc rod to form a receiving cavity between it and the soil nail until each limit rod is inserted into the corresponding limit groove. Then pour concrete into the receiving cavity and start the drive motor to drive each arc rod to move away from the preset hole until it is disengaged from the preset hole.

[0026] S4. When the preset hole is filled with concrete, the mounting shell and the arc rod are simultaneously disengaged from the preset hole. Loosen the bolts on the limiting plate to disassemble the limiting plate from the soil nail. Pull the support tube away from the soil nail. The support tube is disengaged from the soil nail and the mounting shell. Continue to start the drive motor to drive the mounting shell to gradually detach from one end of the soil nail.

[0027] S5. Hang a steel mesh at the end of the soil nail that extends out of the slope;

[0028] S6. Shot concrete on the slope until it is covered with a steel mesh.

[0029] By adopting the above technical solution, it is easy to fill the pre-set hole with concrete, thereby strengthening the connection between the soil nail and the slope, and making the support structure of the deep foundation pit more stable.

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

[0031] 1. Gradually pour concrete into the gap formed between the curved rod and the soil nail to facilitate better filling of the pre-set hole with concrete;

[0032] 2. The connecting component connects adjacent curved rods together and can automatically lock adjacent curved rods together;

[0033] 3. The connection between the soil nails and the slope was strengthened, making the support structure of the deep foundation pit more stable. Attached Figure Description

[0034] Figure 1 This is a schematic diagram illustrating the support structure in an embodiment of this application.

[0035] Figure 2 This is a schematic diagram illustrating how soil nails drive support pipes to be inserted into a preset hole, according to an embodiment of this application.

[0036] Figure 3 This is a schematic diagram illustrating the structure of each arc-shaped rod moving radially along the soil nail until it contacts the inner wall of the preset hole, as shown in the embodiment of this application.

[0037] Figure 4 This is a schematic diagram illustrating the movement of the control component to approach the bottom wall structure of the preset hole in an embodiment of this application.

[0038] Figure 5 This is a schematic diagram illustrating the structure of the limiting component in an embodiment of this application.

[0039] Explanation of reference numerals in the attached drawings: 1. Slope; 11. Pre-set hole; 2. Soil nail; 21. Guide groove; 3. Support pipe; 31. Arc rod; 311. Transition cavity; 312. First chamber; 313. Second chamber; 314. Limiting groove; 32. Receiving cavity; 33. First through hole; 34. Second through hole; 4. Connecting assembly; 41. Elastic connecting rod; 42. First elastic block; 43. Second elastic block; 5. Control assembly; 51. Mounting shell; 511. Mounting hole; 52. Guide block; 53. Nut; 54. Gear; 55. Rotating shaft; 56. Drive motor; 57. Limiting rod; 6. Restriction assembly; 61. Restriction plate; 611. Connecting hole; 612. Transition hole; 62. Insertion rod. Detailed Implementation

[0040] The following is in conjunction with the appendix Figures 1-5 This application will be described in further detail.

[0041] This application discloses a deep foundation pit support structure. (Refer to...) Figure 1 and Figure 2 The deep foundation pit support structure includes a slope 1. Several pre-drilled holes 11 are provided on one side wall of the slope 1. The pre-drilled holes 11 are used to insert soil nails 2. The diameter of the pre-drilled holes 11 is larger than the diameter of the soil nails 2. One end of the soil nail 2 is a pointed tip. After the pointed tip of the soil nail 2 is aligned with the pre-drilled hole 11 and inserted into the pre-drilled hole 11, the other end of the soil nail 2 remains on the outside of the slope 1 and is used to hang steel mesh.

[0042] A support tube 3 is sleeved on the outside of the soil nail 2. The support tube 3 is formed by splicing multiple arc-shaped rods 31. Multiple connecting components 4 are connected between every two adjacent arc-shaped rods 31. The multiple connecting components 4 are evenly distributed along the length of the support tube 3. A control component 5 is connected to the soil nail 2 to push each arc-shaped rod 31 to move radially along the soil nail 2.

[0043] Reference Figure 1 , Figure 2 and Figure 3 After each arc-shaped rod 31 moves radially along the soil nail 2, the gap formed between the multiple arc-shaped rods 31 and the outer wall of the soil nail 2 is the receiving cavity 32.

[0044] After the soil nail 2 is inserted into the preset hole 11, the control component 5 drives each arc-shaped rod 31 to move radially along the soil nail 2 until the outer wall of each arc-shaped rod 31 contacts the inner wall of the preset hole 11. The arc-shaped rods 31 push the soil clods in the preset hole 11 towards the inner wall of the preset hole 11. At this time, concrete can be poured into the receiving cavity 32, and the concrete flows along the receiving cavity 32 towards the bottom wall of the preset hole 11. At the same time, the support tube 3 is pulled to gradually move away from the preset hole 11 until the support tube 3 disengages from the soil nail 2 and the preset hole 11, which facilitates the smooth pouring of concrete into the preset hole 11. The support tube 3 can also be reused.

[0045] The connecting assembly 4 includes an elastic connecting rod 41 fixedly connected to one side wall of each arc-shaped rod 31. The other side wall of each arc-shaped rod 31 has multiple transition cavities 311 arranged along the length of the arc-shaped rod 31, with one elastic connecting rod 41 corresponding to one transition cavity 311. One end of each elastic connecting rod 41 is fixedly connected to a first elastic block 42 and a second elastic block 43, both of which gradually taper towards each other in a mutually distancing direction.

[0046] Each transition cavity 311 has a first chamber 312 on one side and a second chamber 313 on the other side. A first through hole 33 connecting the transition cavity 311 to the first chamber 312 is formed on one side wall of the transition cavity 311, and a second through hole 34 connecting the transition cavity 311 to the second chamber 313 is formed on the other side wall of the transition cavity 311. The maximum diameter of the first elastic block 42 is larger than the diameter of the first through hole 33, and the maximum diameter of the second elastic block 43 is larger than the second through hole 34. When adjacent arc-shaped rods 31 come into contact with each other, the first elastic block 42 passes through the first through hole 33 and is inserted into the first chamber 312. At this time, the second elastic block 43 remains in the transition cavity 311, and the inner wall of the support tube 3 is tightly pressed against the outer wall of the soil nail 2, making it difficult for the support tube 3 to slide relative to the soil nail 2.

[0047] When each arc-shaped rod 31 is pushed to move radially away from the soil nail 2, adjacent arc-shaped rods 31 move away from each other. At this time, each arc-shaped rod 31 drives the first elastic block 42 and the second elastic block 43 to move away from the first chamber 312. The first elastic block 42 is squeezed by the side wall of the first through hole 33 and disengages from the first through hole 33. At this time, the first elastic block 42 disengages from the first chamber 312. The elastic connecting rod 41 deforms and drives the first elastic block 42 and the second elastic block 43 to slide along the transition cavity 311 until the second elastic block 43 is squeezed and deformed by the side wall of the second through hole 34 and inserts into the second chamber 313 through the second through hole 34. At this time, adjacent arc-shaped rods 31 are locked together, and the outer wall of each arc-shaped rod 31 contacts the inner wall of the preset hole 11.

[0048] Reference Figure 1 and Figure 4 The control component 5 includes a mounting shell 51 with a mounting hole 511 through which a soil nail 2 penetrates. A guide block 52 is fixedly connected to the inner wall of the mounting hole 511. A guide groove 21, extending along the length of the soil nail 2, is formed on the outer wall of the soil nail 2. The guide block 52 is slidably connected to the guide groove 21. A nut 53 is rotatably connected to the inner wall of the mounting shell 51. The soil nail 2 passes through the nut 53 and is threadedly connected to it. Several protruding teeth are provided on the outer wall of the nut 53. A gear 54, meshing with the protruding teeth on the nut 53, is provided inside the mounting shell 51. A rotating shaft 55 is rotatably connected inside the mounting shell 51 and is coaxially fixedly connected to the gear 54. A drive motor 56 is mounted on the outer wall of the mounting shell 51 away from the preset hole 11. The output shaft of the drive motor 56 is coaxially fixedly connected to the rotating shaft 55. The bottom wall of the mounting shell 51, near the preset hole, gradually tapers to a pointed tip. A limiting component 6, restricting the rotation of the soil nail 2, is connected to the soil nail 2.

[0049] Align the mounting hole 511 with the end of the soil nail 2 furthest from the preset hole 11, control the guide block 52 to slide into the guide groove 21, start the drive motor 56, and simultaneously restrict the rotation of the soil nail 2 through the limiting component 6. The output shaft of the drive motor 56 rotates, driving the gear 54 to rotate through the rotating shaft 55. The rotation of the gear 54 drives the screw nut 53 to rotate, and the rotation of the screw nut 53 drives the mounting shell 51 to move gradually towards the support tube 3 along the soil nail 2. The tip of the mounting shell 51 is inserted into the end of the support tube 3 near the slope, and the mounting shell 51 gradually inserts into the support tube 3. The mounting shell 51 pushes each arc rod 31 to move gradually away from the soil nail 2 in the direction of approaching the bottom wall of the preset hole 11. When the mounting shell 51 moves to the end of the support tube 3 near the bottom wall of the preset hole 11, each arc rod 31 disengages from the soil nail 2 and abuts against the inner wall of the preset hole 11.

[0050] The end of the support tube 3 away from the bottom wall of the preset hole 11 is provided with a flared opening, which facilitates the insertion of the tip of the mounting shell 51.

[0051] Multiple limiting rods 57 are fixedly connected to the outer wall of the mounting shell 51, and the multiple limiting rods 57 are evenly distributed around the periphery of the mounting shell 51. Multiple limiting grooves 314 are formed at the end of the arc-shaped rod 31 near the bottom wall of the preset hole 11, with one limiting rod 57 corresponding to one limiting groove 314. When the mounting shell 51 moves to the end of the support tube 3 near the bottom wall of the preset hole 11, each limiting rod 57 is inserted into the corresponding limiting groove 314.

[0052] The drive motor 56 is reversed. At this time, the mounting shell 51 gradually moves away from the bottom wall of the preset hole 11 along the soil nail 2. The movement of the mounting shell 51 drives the limiting rod 57 to move. The limiting rod 57 moves until it touches the side wall of the limiting groove 314 away from the bottom wall of the preset hole 11. The continued movement of the limiting rod 57 then drives each arc-shaped rod 31 to move away from the bottom wall of the preset hole 11. In this way, the mounting shell 51 drives the support tube 3 to gradually detach from the preset hole 11. During this process, concrete is poured into the receiving cavity 32 through the gap between the mounting tube and the inner wall of the arc-shaped rod 31. The concrete flows into the preset hole 11 along the receiving cavity 32. As the support tube 3 exits the preset hole 11, the concrete gradually fills the preset hole 11.

[0053] Reference Figure 5 The limiting component 6 includes a limiting plate 61 and multiple plug-in rods 62. The limiting plate 61 has a connecting hole 611. One end of the soil nail 2 protruding from the preset hole 11 is inserted into the connecting hole 611, and the limiting plate 61 and the soil nail 2 are fastened together by bolts. The multiple plug-in rods 62 are fixed to a surface of the limiting plate 61 near the slope 1, and each plug-in rod 62 is fastened into the slope 1.

[0054] Reference Figure 4 and Figure 5 The limiting plate 61 has three transition holes 612 on one surface for the arc rods 31 to pass through. As the mounting shell 51 drives the support tube 3 to gradually exit the preset hole 11, one transition hole 612 corresponds to one arc rod 31, and each arc rod 31 gradually inserts into the corresponding transition hole 612.

[0055] This application also discloses a construction method for a deep foundation pit support structure, including the following steps:

[0056] S1, slope 1 excavation.

[0057] S2. Pre-drill holes 11 on slope 1 and insert soil nails 2 into each pre-drill hole 11.

[0058] S3. Start the drive motor 56. The mounting housing 51 pushes each arc rod 31 to form a receiving cavity 32 between it and the soil nail 2 until each limiting rod 57 is inserted into the corresponding limiting groove 314. Then, pour concrete into the receiving cavity 32. At the same time, start the drive motor 56 to drive each arc rod 31 to move away from the preset hole 11 until it is disengaged from the preset hole 11.

[0059] S4. When the preset hole 11 is filled with concrete, the mounting shell 51 and the arc rod 31 are simultaneously disengaged from the preset hole 11. Loosen the bolts on the limiting plate 61 to disassemble the limiting plate 61 from the soil nail 2. Pull the support tube 3 away from the soil nail 2. The support tube 3 is disengaged from the soil nail 2 and the mounting shell 51. Continue to start the drive motor 56 to drive the mounting shell 51 to gradually detach from one end of the soil nail 2.

[0060] S5. Hang a steel mesh at the end of soil nail 2 that extends out of slope 1.

[0061] S6. Shot concrete on slope 1 until it is covered with steel mesh.

[0062] 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 deep foundation pit supporting structure, comprising a preset hole (11) formed on a slope (1), and a soil nail (2) inserted into the preset hole (11), characterized in that: The outer side wall of the soil nail (2) is sleeved with a support pipe (3), the support pipe (3) comprises a plurality of arc-shaped rods (31), the plurality of arc-shaped rods (31) are mutually spliced around the circumference of the soil nail (2), a plurality of connecting assemblies (4) are connected between every two adjacent arc-shaped rods (31), and the soil nail (2) is connected with a control assembly (5) for driving each arc-shaped rod (31) to move along the soil nail (2) in the radial direction until the arc-shaped rod (31) contacts the inner wall of the preset hole (11); The connecting assembly (4) comprises an elastic connecting rod (41) fixedly connected with one side wall of the arc-shaped rod (31), a transition cavity (311), a first cavity (312) and a second cavity (313) are formed in one end of each arc-shaped rod (31) away from the elastic connecting rod (41), the transition cavity (311) is located between the first cavity (312) and the second cavity (313), a first through hole (33) communicating with the first cavity (312) is formed in one side wall of the transition cavity (311), a second through hole (34) communicating with the second cavity (313) is formed in the other side wall of the transition cavity (311), one end of the elastic connecting rod (41) is fixedly connected with a first elastic block (42) and a second elastic block (43), the diameter of the first elastic block (42) is greater than that of the first through hole (33), the first elastic block (42) is inserted into the first cavity (312), the second elastic block (43) is arranged in the transition cavity (311), and the diameter of the second elastic block (43) is greater than that of the second through hole (34); when the adjacent arc-shaped rods (31) move away from each other, the first elastic block (42) is separated from the first cavity (312), and the second elastic block (43) is inserted into the second cavity (313); The control assembly (5) comprises a mounting shell (51) provided with a mounting hole (511), the inner wall of the mounting hole (511) is fixedly connected with a guide block (52), a guide groove (21) is formed in the side wall of the soil nail (2), the soil nail (2) penetrates into the mounting hole (511) and the guide block (52) and the guide groove (21) are slidably connected, one end of the mounting shell (51) close to the preset hole (11) is provided with a pointed end, a female screw (53) is rotatably connected in the mounting shell (51), the female screw (53) is threadedly connected with the soil nail (2), a row of convex teeth are arranged on the outer side wall of the female screw (53), the convex teeth are engaged with a gear (54), the gear (54) is rotatably connected in the mounting shell (51), and a driving motor (56) is connected to the mounting shell (51) and drives the gear (54) to rotate, and the soil nail (2) is connected with a limiting assembly (6) for limiting the rotation of the soil nail (2).

2. A deep foundation pit support structure according to claim 1, wherein: The first elastic block (42) and the second elastic block (43) gradually shrink in the direction away from each other and become pointed ends.

3. The deep foundation pit support structure according to claim 1, characterized in that: The outer side wall of the mounting shell (51) is fixedly connected with a plurality of limiting rods (57), each of the arc-shaped rods (31) is provided with a limiting slot (314) in the inner wall of one end close to the bottom wall of the preset hole (11), and each limiting rod (57) is inserted into the corresponding limiting slot (314) when the mounting shell (51) moves to the inside of the support pipe (3) close to one end of the bottom wall of the preset hole (11).

4. The deep foundation pit support structure according to claim 1, characterized in that: The support pipe (3) is provided with a flared end away from the bottom wall of the preset hole (11).

5. The deep foundation pit support structure according to claim 1, characterized in that: The limiting assembly (6) comprises a limiting plate (61) fixedly connected with one end of the soil nail (2) away from the bottom wall of the preset hole (11) through a screw, a plurality of insertion rods (62) are fixedly connected to the limiting plate (61) and inserted into the slope (1), and a plurality of transition holes (612) are formed in the limiting plate (61) and passed through by the arc-shaped rods (31).

6. A construction method of applying the deep foundation pit supporting structure according to any one of claims 3-5, characterized in that, The method comprises the following steps: S1, excavating the slope (1); S2, forming the preset hole (11) on the slope (1), and inserting the soil nail (2) into each preset hole (11); S3, starting the driving motor (56), the mounting shell (51) pushes each arc-shaped rod (31) to form a receiving cavity (32) between the arc-shaped rod (31) and the soil nail (2), until each limiting rod (57) is inserted into the corresponding limiting slot (314), and then pouring concrete into the receiving cavity (32), while starting the driving motor (56) to drive each arc-shaped rod (31) to move away from the preset hole (11) until the arc-shaped rod (31) is separated from the preset hole (11); S4, when the preset hole (11) is filled with concrete, the mounting shell (51) and the arc-shaped rod (31) are separated from the preset hole (11), the bolts on the limiting plate (61) are loosened, and the limiting plate (61) is separated from the soil nail (2), the support pipe (3) is pulled away from the soil nail (2) and the mounting shell (51), and the driving motor (56) is continuously started to drive the mounting shell (51) to gradually separate from the soil nail (2) from one end of the soil nail (2); S5, hanging a steel mesh on one end of the soil nail (2) extending out of the slope (1); S6, spraying concrete on the slope (1) to cover the steel mesh.

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