Foundation pit hollow support pile and construction method thereof

Abstract

The invention relates to the technical field of foundation pit supporting, in particular to a foundation pit hollow supporting pile and a construction method thereof.The foundation pit hollow supporting pile comprises a hollow steel pipe pile, a lock catch mechanism and a supporting mechanism, the hollow steel pipe pile is arranged in a foundation pit, and the lock catch mechanism used for clamping and locking the hollow steel pipe pile is clamped outside the hollow steel pipe pile; the supporting mechanism is connected between the two adjacent lock catch mechanisms and used for supporting the lock catch mechanisms, the two adjacent hollow steel pipe piles can be rapidly clamped and locked through the arrangement of the lock catch mechanisms, meanwhile, the two adjacent hollow steel pipe piles are supported and fixed through the arrangement of the supporting mechanism, and the stability and safety of the supporting system are enhanced; the method effectively prevents engineering accidents such as slope instability and land subsidence, is higher in overall adaptability of supporting, is particularly suitable for deep foundation pit construction under complex geological conditions, and provides reliable technical support for urban construction and development.

Description

Technical Field

[0001] The present application relates to the technical field of foundation pit support, and in particular to a foundation pit hollow support pile and a construction method thereof. Background Art

[0002] With the rapid development of urban construction, the number of high-rise buildings is increasing, resulting in the continuous increase in the depth of foundation pit excavation. Traditional foundation pit support methods mainly include reinforced concrete support, steel sheet piles, underground continuous walls, etc. Although these traditional support methods have guaranteed construction safety to a certain extent, they also have problems such as high cost, long construction period, and great environmental impact. In recent years, with the application of new materials and new technologies, many new foundation pit support methods have emerged, such as prestressed anchor cables and composite foundation reinforcement. These methods have achieved certain results in improving support efficiency and reducing costs, but they still cannot fully meet the needs of deep foundation pit construction under complex geological conditions.

[0003] At present, the existing foundation pit support methods usually rely on traditional reinforced concrete support, steel sheet piles, underground continuous walls, etc. Among them, reinforced concrete support has the characteristics of high strength and good stability, but the construction period is long and the cost is high; steel sheet piles have the advantages of fast construction speed and high recovery rate, but they are prone to deformation in soft soil layers; underground continuous walls are widely used in areas with abundant groundwater due to their good waterproof performance, but the construction is difficult and the cost is expensive. In addition, prestressed anchor cables improve the support effect by increasing the shear strength inside the soil, but their scope of application is limited and it is difficult to cope with complex geological conditions.

[0004] The common problems of the above-mentioned traditional support methods are long construction period, high cost and great impact on the environment. Especially under complex geological conditions, it is easy to cause a series of engineering accidents, such as slope instability and ground subsidence. Therefore, the development of an efficient, economical and environmentally friendly foundation pit support method has become the focus of current research. Summary of the invention

[0005] In order to solve the problems that the current foundation pit support construction has a long construction period, high cost, and great impact on the environment, especially under complex geological conditions, which easily leads to a series of engineering accidents, the present application provides a foundation pit hollow support pile and a construction method thereof.

[0006] In the first aspect, the hollow supporting piles for foundation pit provided in the present application adopt the following technical solutions: A hollow supporting pile for a foundation pit, comprising: Hollow steel pipe piles, which are arranged in a foundation pit; A locking mechanism, which is used to lock the hollow steel pipe pile, the locking mechanism is locked on the outside of the hollow steel pipe pile, and the locking mechanism includes a fixed seat, a limit seat, a linkage rod and a locking plate, the limit seat is fixed to one end of the fixed seat, one end of the linkage rod is rotatably connected to the limit seat, and the other end is rotatably connected to the locking plate, and the locking plate abuts against the hollow steel pipe pile; A support mechanism is used to support the locking mechanism, and the support mechanism is connected between two adjacent locking mechanisms. The support mechanism includes a support rod and a telescopic rod. A rectangular cavity is provided inside the support rod. The telescopic rod is slidably connected in the rectangular cavity of the support rod, and one end of the telescopic rod is fixed to one of the fixing seats, and one end of the support rod is fixed to the fixing seat at the other end.

[0007] By adopting the above technical solution, the locking mechanism is set up so that when the abutting rod abuts against the hollow steel pipe pile, the movement of the abutting rod can drive the driven rod to work in conjunction, thereby synchronously driving the linkage rod and the locking plate to work in conjunction, and the hollow steel pipe pile is quickly clamped and locked by the locking plate, thereby achieving a quick locking effect on the hollow steel pipe pile; The supporting mechanism is used to support two adjacent locking mechanisms and to support and fix two adjacent hollow steel pipe piles, thereby improving the overall structural stability of the hollow steel pipe piles. At the same time, through the setting of structures such as the adjusting rod, the adjusting rod can drive the second pawl to synchronously link during the reciprocating rotation, and the telescopic rod is pushed to slide in the supporting rod through the second pawl, thereby realizing rapid adjustment of the overall length of the supporting mechanism, which is simple and efficient.

[0008] Optionally, the locking mechanism also includes an abutment rod and a driven rod, an installation cavity is provided at the center of the limit seat, the abutment rod is slidably engaged at the center of the installation cavity of the limit seat, and is partially located outside the limit seat, one end of the driven rod is rotatably connected to an end of the abutment rod away from the limit seat, and the other end of the driven rod is fixed to an end of the locking plate close to the linkage rod.

[0009] By adopting the above technical solution, the sliding of the abutment rod is utilized to drive the driven rod to move in linkage, and then the driven rod drives the linkage rod and the locking plate to move in linkage synchronously as a whole.

[0010] Optionally, the locking mechanism also includes a first ratchet groove and a first pawl, the first ratchet groove is arranged on the side wall of the abutment rod, the first pawl is rotatably connected to the mounting cavity of the limit seat through a rotating rod, and a torsion spring is sleeved on the rotating rod of the first pawl, one end of the torsion spring is fixed to the limit seat, and the other end is fixed to the first pawl, and one end of the first pawl abuts against the first ratchet groove.

[0011] By adopting the above technical solution, the abutment rod is limited and locked by the first ratchet to prevent the abutment rod from sliding in the opposite direction.

[0012] Optionally, the support mechanism also includes a docking seat, a connecting rod, an adjusting rod and a second pawl, the docking seat is fixed on the support rod, the connecting rod is rotatably connected to the docking seat, one end of the adjusting rod is fixed to the connecting rod, and the adjusting rod is rotatably connected to the docking seat via the connecting rod, one end of the second pawl is rotatably connected to the adjusting rod, and a second ratchet groove is provided on the upper surface of the telescopic rod, and a notch is penetrated on the support rod, one end of the second pawl passes through the rectangular notch and is slidably engaged in the second ratchet groove of the telescopic rod.

[0013] By adopting the above technical solution, the reciprocating rotation of the adjusting rod drives the second ratchet to be linked, so that the second ratchet abuts against the second ratchet grooves at different positions, thereby pushing the telescopic rod to slide quickly in the support rod.

[0014] Optionally, a first reset member is sleeved on the outside of the connecting rod, one end of the first reset member is fixed to the docking seat, and a clamping rod is fixed on the side wall of the adjusting rod, and the other end of the first reset member is fixed to the clamping rod.

[0015] By adopting the above technical solution, the adjusting rod can be quickly reset by utilizing the elastic force of the first reset member. Optionally, a second reset member is provided between the adjusting rod and the second pawl.

[0016] By adopting the above technical solution, the second reset member is used to enable one end of the second pawl to always abut against the telescopic rod.

[0017] Optionally, a lever is fixed to one end of the second pawl away from the support rod, and a slide groove is provided through the adjusting rod, and the lever passes through the slide groove.

[0018] By adopting the above technical solution, the second pawl is driven to rotate by the lever, so that the second pawl can be quickly separated from the telescopic rod, and the telescopic rod can be quickly moved on the support rod.

[0019] Optionally, the overall structure formed by the linkage rod and the locking plate is symmetrically arranged in at least two groups on both sides of the limiting seat.

[0020] By adopting the above technical solution, the locking mechanism can firmly lock the hollow steel pipe pile by using the symmetrically arranged locking plates.

[0021] Optionally, a grouting pipe is provided through the center of the hollow steel pipe pile, reinforcing ribs are provided on the inner and outer surfaces of the hollow steel pipe pile, a water stop ring is provided on the top of the hollow steel pipe pile, and a grouting hole is provided at the bottom of the hollow steel pipe pile.

[0022] By adopting the above technical solution, cement slurry or other curing agents are injected into the soil layer using a grouting pipe to enhance the stability of the soil, and the bending and shear resistance of the hollow steel pipe piles is increased through reinforcement, and a water stop ring is used to prevent groundwater from penetrating into the foundation pit.

[0023] In a second aspect, the present application also provides a construction method, comprising the following steps: S1. Determine the position and depth of hollow steel pipe piles according to the foundation pit design drawings; S2. Use a hydraulic pile driver to drive the hollow steel pipe pile into the soil layer, keeping the verticality error within 1%; S3. Check whether the distance between hollow steel pipe piles meets the requirements and make timely adjustments if there is any deviation; S4, setting the locking mechanism and the supporting mechanism between two adjacent hollow steel pipe piles, and adjusting the overall length of the supporting mechanism so that the locking mechanism abuts against the hollow steel pipe piles, and locking the two adjacent hollow steel pipe piles through the locking mechanism to ensure a tight connection without looseness; S5. Connect the grouting pump and grouting pipe, start grouting operation, and control the grouting pressure within the range of 0.5-1.0MPa; S6. Observe the grouting conditions and adjust the grouting volume and speed in a timely manner until the soil is fully solidified; S7. Turn off the grouting pump, clean up the tools and equipment on site, and seal the grouting holes and water stop rings; S8. Regularly monitor the soil changes around the foundation pit to ensure the normal operation of the support system By adopting the above technical solution and using multiple steps to guide the construction, the overall construction period of the foundation pit support pile structure is greatly reduced, and at the same time the cost and environmental impact are effectively controlled. The hollow structure allows cement slurry or other curing agents to be injected into the soil layer, avoiding a series of engineering accidents under complex geological conditions and eliminating safety hazards.

[0024] In summary, the present application includes at least one of the following beneficial technical effects: 1. The locking mechanism is set so that when the abutting rod abuts against the hollow steel pipe pile, the movement of the abutting rod can drive the driven rod to work in conjunction, thereby synchronously driving the linkage rod and the locking plate to work in conjunction, and the hollow steel pipe pile can be quickly clamped and locked by the locking plate, thereby achieving a quick locking effect on the hollow steel pipe pile; 2. The support mechanism is used to support two adjacent locking mechanisms and to support and fix two adjacent hollow steel pipe piles, thereby improving the overall structural stability of the hollow steel pipe piles. At the same time, the adjustment rod and other structures are set up so that the adjustment rod can drive the second ratchet to move synchronously during the reciprocating rotation, and the telescopic rod is pushed to slide in the support rod through the second ratchet, thereby realizing the rapid adjustment of the overall length of the support mechanism. This is simple and efficient, greatly shortening the time of foundation pit support construction, improving work efficiency, and reducing overall construction costs. 3. The construction is guided by multiple steps, which greatly reduces the overall construction period of the foundation pit support pile structure, and at the same time effectively controls the cost and environmental impact. The hollow structure allows cement slurry or other curing agents to be injected into the soil layer, avoiding a series of engineering accidents under complex geological conditions, eliminating safety hazards, enhancing the stability and safety of the support system, and effectively preventing the occurrence of engineering accidents such as slope instability and ground subsidence. The overall support has stronger adaptability, which is especially suitable for deep foundation pit construction under complex geological conditions, and provides reliable technical support for urban construction and development. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the combined structure of hollow steel pipe piles of a foundation pit hollow supporting pile and its construction method in this embodiment.

[0026] Figure 2 It is a schematic diagram of the external structure of the locking mechanism and the supporting mechanism in this embodiment.

[0027] Figure 3 Schematic diagram of the supporting mechanism structure in this embodiment.

[0028] Figure 4 Schematic diagram of the second pawl structure in this embodiment.

[0029] Figure 5 Schematic diagram of the locking mechanism structure in this embodiment.

[0030] Description of reference numerals: 1. Hollow steel pipe pile; 2. Locking mechanism; 21. Fixed seat; 22. Limiting seat; 23. Linking rod; 24. Locking plate; 25. Abutting rod; 26. Driven rod; 27. First ratchet groove; 28. First pawl; 3. Support mechanism; 31. Support rod; 32. Telescopic rod; 33. Docking seat; 34. Connecting rod; 35. Adjusting rod; 36. Second ratchet; 37. Clamping rod; 38. First reset member; 39. Second reset member; 310. Push rod; 311. Slide groove. DETAILED DESCRIPTION

[0031] The following is combined with Figure 1-5 This application is described in further detail.

[0032] The embodiment of the present application discloses a foundation pit hollow supporting pile and a construction method thereof.

[0033] It should be noted that, in the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicating orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0034] In the first aspect, the present application provides a hollow supporting pile for a foundation pit: Reference Figure 1 and Figure 2 A hollow supporting pile for a foundation pit comprises a hollow steel pipe pile 1, a locking mechanism 2 and a supporting mechanism 3. The hollow steel pipe pile 1 is arranged in the foundation pit. The locking mechanism 2 for locking the hollow steel pipe pile 1 is buckled on the outside of the hollow steel pipe pile 1. The supporting mechanism 3 is connected between two adjacent locking mechanisms 2 and is used to support the locking mechanism 2. The locking mechanism 2 is used to enable the two adjacent hollow steel pipe piles 1 to be quickly clamped and locked, and at the same time, the supporting mechanism 3 is used to support and fix the two adjacent hollow steel pipe piles 1, thereby improving the overall structural stability of the hollow steel pipe pile 1.

[0035] Specifically, the locking mechanism 2 includes a supporting mechanism 3, a fixing seat 21, a limiting seat 22, a linkage rod 23, a locking plate 24, an abutting rod 25 and a driven rod 26. The setting of the locking mechanism 2 enables the abutting rod 25 to drive the driven rod 26 to move when it abuts against the hollow steel pipe pile 1, thereby synchronously driving the linkage rod 23 and the locking plate 24 to move, and quickly clamping and locking the hollow steel pipe pile 1 through the locking plate 24, thereby achieving a quick locking effect on the hollow steel pipe pile 1.

[0036] The limiting seat 22 is fixed to one end of the fixing seat 21, one end of the linkage rod 23 is rotatably connected to the limiting seat 22, and the other end is rotatably connected to the locking plate 24, the locking plate 24 abuts against the hollow steel pipe pile 1, and an installation cavity is provided at the center of the limiting seat 22, the abutting rod 25 is slidably engaged at the center of the installation cavity of the limiting seat 22, and part of it is located outside the limiting seat 22, one end of the driven rod 26 is rotatably connected to one end of the abutting rod 25 away from the limiting seat 22, and the other end of the driven rod 26 is fixed to one end of the locking plate 24 close to the linkage rod 23.

[0037] Reference Figure 3 and Figure 4In the embodiment of the present application, regarding the support mechanism 3, the support mechanism 3 includes a support rod 31, a telescopic rod 32, a docking seat 33, a connecting rod 34, an adjusting rod 35 and a second ratchet 36. The setting of the support mechanism 3 is used to support the two adjacent locking mechanisms 2, and to support and fix the two adjacent hollow steel pipe piles 1, thereby improving the overall structural stability of the hollow steel pipe piles 1. At the same time, through the setting of the adjusting rod 35 and other structures, the adjusting rod 35 can drive the second ratchet 36 to synchronously link during the reciprocating rotation, and the telescopic rod 32 is pushed to slide in the support rod 31 through the second ratchet 36, thereby realizing the rapid adjustment of the overall length of the support mechanism 3, which is simple and efficient.

[0038] Specifically, a rectangular cavity is provided inside the support rod 31, the telescopic rod 32 is slidably connected in the rectangular cavity of the support rod 31, and one end of the telescopic rod 32 is fixed to one of the fixed seats 21, one end of the support rod 31 is fixed to the other end fixed seat 21, the docking seat 33 is fixed on the support rod 31, the connecting rod 34 is rotatably connected to the docking seat 33, one end of the adjusting rod 35 is fixed to the connecting rod 34, and the adjusting rod 35 is rotatably connected to the docking seat 33 through the connecting rod 34, one end of the second pawl 36 is rotatably connected in the adjusting rod 35, and a second ratchet groove is provided on the upper surface of the telescopic rod 32, and a notch is provided on the support rod 31, one end of the second pawl 36 passes through the rectangular notch and is slidably engaged in the second ratchet groove of the telescopic rod 32.

[0039] Reference Figure 5 Specifically, in the embodiment of the present application, the locking mechanism 2 also includes a first ratchet groove 27 and a first ratchet pawl 28. The first ratchet groove 27 is arranged on the side wall of the abutment rod 25. The first ratchet pawl 28 is rotatably connected to the mounting cavity of the limit seat 22 through a rotating rod, and a torsion spring is sleeved on the rotating rod of the first ratchet 28. One end of the torsion spring is fixed to the limit seat 22, and the other end is fixed to the first ratchet 28. One end of the first ratchet 28 abuts against the first ratchet groove 27, and the first ratchet pawl 28 is used to limit and lock the abutment rod 25 to prevent the abutment rod 25 from sliding in the opposite direction.

[0040] In the embodiment of the present application, a first reset member 38 is sleeved on the outside of the connecting rod 34, one end of the first reset member 38 is fixed to the docking seat 33, and a clamping rod 37 is fixed to the side wall of the adjusting rod 35, the other end of the first reset member 38 is fixed to the clamping rod 37, and a second reset member 39 is arranged between the adjusting rod 35 and the second pawl 36. The elastic force of the first reset member 38 is utilized to quickly reset the adjusting rod 35, and the second reset member 39 is utilized to ensure that one end of the second pawl 36 can always be in contact with the telescopic rod 32.

[0041] Regarding the second pawl 36, a lever 310 is fixed to the end of the second pawl 36 away from the support rod 31, and a slide groove 311 is penetrated on the adjustment rod 35. The lever 310 passes through the slide groove 311, and the lever 310 is used to drive the second pawl 36 to rotate, so that the second pawl 36 can be quickly separated from the telescopic rod 32, so that the telescopic rod 32 can move quickly on the support rod 31.

[0042] The integral structure composed of the linkage rod 23 and the locking plate 24 is symmetrically arranged in at least two groups on both sides of the limiting seat 22 . The locking mechanism 2 can firmly lock the hollow steel pipe pile 1 by utilizing the symmetrically arranged locking plates 24 .

[0043] In the embodiment of the present application, a grouting pipe is provided through the center of the hollow steel pipe pile 1, and reinforcing ribs are provided on the inner and outer surfaces of the hollow steel pipe pile 1, and a water stop ring is provided at the top of the hollow steel pipe pile 1, and a grouting hole is provided at the bottom of the hollow steel pipe pile 1. The grouting pipe is used to inject cement slurry or other curing agents into the soil layer to enhance the stability of the soil, and the bending and shear resistance of the hollow steel pipe pile 1 is increased by the reinforcing ribs, and the water stop ring is used to prevent groundwater from penetrating into the foundation pit.

[0044] The implementation principle of the hollow supporting piles and the construction method of the foundation pit in the embodiment of the present application is as follows: first, the pre-processed hollow steel pipe piles are transported to the construction site, and are driven into the predetermined position by a hydraulic pile driver to ensure that the verticality and flatness meet the design requirements. Subsequently, locking joints are installed between the hollow steel pipe piles to form a stable frame structure. During installation, the locking mechanism 2 and the supporting mechanism 3 are placed as a whole between two adjacent hollow steel pipe piles 1, and then the adjusting rod 35 is reciprocated to push the telescopic rod 32 to slide through the second ratchet 36, so that the locking mechanism 2 It abuts against the hollow steel pipe pile 1. When abutting against the hollow steel pipe pile 1, the abutting rod 25 drives the driven rod 26 to work in conjunction with it through the movement of the abutting rod 25, and then synchronously drives the linkage rod 23 and the locking plate 24 to work in conjunction with each other, and the hollow steel pipe pile 1 is quickly clamped and locked through the locking plate 24. Then, cement slurry or other curing agents are injected into the soil layer through the grouting pipe to significantly improve the bonding force between soil particles, thereby achieving the purpose of consolidating the soil. Finally, after completing the grouting operation, the grouting holes and water stop rings are sealed to ensure a dry environment in the foundation pit.

[0045] Second, refer to Figure 1-Figure 5 , the application also provides a construction method, comprising the following steps: S1. Determine the position and depth of hollow steel pipe piles according to the foundation pit design drawings; S2. Use a hydraulic pile driver to drive the hollow steel pipe pile into the soil layer, keeping the verticality error within 1%; S3. Check whether the distance between hollow steel pipe piles meets the requirements and make timely adjustments if there is any deviation; S4, setting the locking mechanism 2 and the supporting mechanism 3 between two adjacent hollow steel pipe piles 1, and adjusting the overall length of the supporting mechanism 3 to make the locking mechanism 2 abut against the hollow steel pipe pile 1, and locking the two adjacent hollow steel pipe piles 1 through the locking mechanism 2 to ensure a tight connection without looseness; S5. Connect the grouting pump and grouting pipe, start grouting operation, and control the grouting pressure within the range of 0.5-1.0MPa; S6. Observe the grouting conditions and adjust the grouting volume and speed in a timely manner until the soil is fully solidified; S7. Turn off the grouting pump, clean up the tools and equipment on site, and seal the grouting holes and water stop rings; S8. Regularly monitor the soil changes around the foundation pit to ensure the normal operation of the support system.

[0046] This application utilizes multiple steps to guide the construction, which greatly reduces the overall construction period of the foundation pit support pile structure, while effectively controlling the cost and environmental impact. The hollow structure enables cement slurry or other curing agents to be injected into the soil layer, avoiding a series of engineering accidents under complex geological conditions and eliminating safety hazards.

[0047] 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. A hollow supporting pile for foundation pit, characterized in that: include: A hollow steel pipe pile (1), wherein the hollow steel pipe pile (1) is arranged in a foundation pit; A locking mechanism (2) for locking the hollow steel pipe pile (1) by clamping, the locking mechanism (2) being clamped on the outside of the hollow steel pipe pile (1), and comprising a fixing seat (21), a limiting seat (22), a linkage rod (23) and a locking plate (24), the limiting seat (22) being fixed to one end of the fixing seat (21), one end of the linkage rod (23) being rotatably connected to the limiting seat (22), and the other end being rotatably connected to the locking plate (24), and the locking plate (24) being in contact with the hollow steel pipe pile (1); A support mechanism (3) is used to support the locking mechanism (2), and the support mechanism (3) is connected between two adjacent locking mechanisms (2), the support mechanism (3) comprises a support rod (31) and a telescopic rod (32), a rectangular cavity is provided inside the support rod (31), the telescopic rod (32) is slidably connected in the rectangular cavity of the support rod (31), and one end of the telescopic rod (32) is fixed to one of the fixing seats (21), and one end of the support rod (31) is fixed to the fixing seat (21) at the other end.

2. A hollow supporting pile for foundation pit according to claim 1, characterized in that: The locking mechanism (2) further comprises an abutting rod (25) and a driven rod (26); a mounting cavity is provided at the center of the limiting seat (22); the abutting rod (25) is slidably engaged at the center of the mounting cavity of the limiting seat (22), and is partially located outside the limiting seat (22); one end of the driven rod (26) is rotatably connected to an end of the abutting rod (25) away from the limiting seat (22); and the other end of the driven rod (26) is fixed to an end of the locking plate (24) close to the linkage rod (23).

3. A hollow supporting pile for foundation pit according to claim 2, characterized in that: The locking mechanism (2) further comprises a first ratchet groove (27) and a first ratchet pawl (28), wherein the first ratchet groove (27) is arranged on the side wall of the abutting rod (25), the first ratchet pawl (28) is rotatably connected to the mounting cavity of the limiting seat (22) via a rotating rod, and a torsion spring is sleeved on the rotating rod of the first ratchet pawl (28), one end of the torsion spring is fixed to the limiting seat (22), and the other end is fixed to the first ratchet pawl (28), and one end of the first ratchet pawl (28) abuts against the first ratchet groove (27).

4. The hollow supporting pile for foundation pit according to claim 1, characterized in that: The support mechanism (3) further comprises a docking seat (33), a connecting rod (34), an adjusting rod (35) and a second ratchet (36); the docking seat (33) is fixed on the support rod (31); the connecting rod (34) is rotatably connected to the docking seat (33); one end of the adjusting rod (35) is fixed to the connecting rod (34); the adjusting rod (35) is rotatably connected to the docking seat (33) via the connecting rod (34); one end of the second ratchet (36) is rotatably connected inside the adjusting rod (35); a second ratchet groove is provided on the upper surface of the telescopic rod (32); a notch is penetrated through the support rod (31); one end of the second ratchet (36) passes through the rectangular notch and is slidably engaged in the second ratchet groove of the telescopic rod (32).

5. The hollow supporting pile for foundation pit according to claim 4, characterized in that: A first reset member (38) is sleeved on the outside of the connecting rod (34), one end of the first reset member (38) is fixed to the docking seat (33), and a clamping rod (37) is fixed to the side wall of the adjusting rod (35), the other end of the first reset member (38) is fixed to the clamping rod (37).

6. The hollow supporting pile for foundation pit according to claim 4, characterized in that: A second reset member (39) is provided between the adjustment rod (35) and the second ratchet pawl (36).

7. The hollow supporting pile for foundation pit according to claim 4, characterized in that: A lever (310) is fixed to one end of the second pawl (36) away from the support rod (31), and a slide groove (311) is provided through the adjustment rod (35), and the lever (310) passes through the slide groove (311).

8. The hollow supporting pile for foundation pit according to claim 1, characterized in that: The integral structure formed by the linkage rod (23) and the locking plate (24) is symmetrically arranged in at least two groups on both sides of the limiting seat (22).

9. The hollow supporting pile for foundation pit according to claim 1, characterized in that: A grouting pipe is provided through the center of the hollow steel pipe pile (1), reinforcing ribs are provided on the inner and outer surfaces of the hollow steel pipe pile (1), a water stop ring is provided on the top of the hollow steel pipe pile (1), and a grouting hole is provided at the bottom of the hollow steel pipe pile (1).

10. A construction method, applied to a hollow supporting pile for a foundation pit according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1. Determine the position and depth of hollow steel pipe piles according to the foundation pit design drawings; S2. Use a hydraulic pile driver to drive the hollow steel pipe pile into the soil layer, keeping the verticality error within 1%; S3. Check whether the distance between hollow steel pipe piles meets the requirements and make timely adjustments if there is any deviation; S4, arranging the locking mechanism (2) and the supporting mechanism (3) between two adjacent hollow steel pipe piles (1), and adjusting the overall length of the supporting mechanism (3) so that the locking mechanism (2) and the hollow steel pipe pile (1) are in contact, and locking the two adjacent hollow steel pipe piles (1) by the locking mechanism (2) to ensure that the connection is tight and not loose; S5. Connect the grouting pump and grouting pipe, start grouting operation, and control the grouting pressure within the range of 0.5-1.0MPa; S6. Observe the grouting conditions and adjust the grouting volume and speed in a timely manner until the soil is fully solidified; S7. Turn off the grouting pump, clean up the tools and equipment on site, and seal the grouting holes and water stop rings; S8. Regularly monitor the soil changes around the foundation pit to ensure the normal operation of the support system.

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