Construction method of foundation pit supporting structure

Abstract

The foundation pit supporting structure comprises a bottom plate, connecting plates are fixedly connected to the two sides of the bottom plate, a rotating shaft is rotationally connected between the two connecting plates through a bearing, a supporting plate is fixedly connected to the outer side of the rotating shaft, and a receding groove is formed in the side, close to the bottom plate, of the supporting plate; the invention further provides a construction method of the foundation pit supporting structure. The construction method comprises the following steps that S1, construction preparation is conducted, the field environment is determined, perfect protection measures are established, and the foundation pit is cleaned. According to the foundation pit supporting structure, the angle of the supporting plate can be changed, foundation pits with different gradients can be supported by the supporting plate, the applicability of the supporting structure is improved, the situation that the side wall of the foundation pit collapses due to loose and soft soil is avoided, damage to constructors of the foundation pit is avoided, and the use safety of the supporting structure is improved; and the stability of the fixing cone can be improved, and the use stability of the supporting structure is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of foundation pit support, and particularly relates to a construction method for a foundation pit support structure. Background Art

[0002] A foundation pit refers to a temporary earthwork space excavated in construction projects for the construction of underground structures (such as basements, foundations, etc.). It is a key link in the construction process, directly affecting the safety and quality of the project. It is an excavation area that provides construction space for the underground part of a building and usually needs to be backfilled after the completion of the underground structure or used as a permanent space (such as a basement).

[0003] After the foundation pit is excavated, the natural balance of the original soil mass is destroyed, and the lateral pressure may cause soil mass slip or collapse, especially in soft soil, sandy soil layers or deep foundation pits. Therefore, in order to maintain the stability of the soil mass during the excavation process, prevent collapse, and protect the safety of the surrounding environment, it is necessary to support the foundation pit through a foundation pit support structure.

[0004] Currently, when the existing foundation pit support structure supports the foundation pit, the angle of its support plate cannot be changed. Therefore, when facing foundation pits with different slopes, it is not convenient to use, resulting in limitations in the use of the foundation pit support structure. In order to better address the above problems, promote the development of the industry's technical level, and improve the core competitiveness, this application proposes a new composition structure different from the prior art. Summary of the Invention

[0005] (I) Technical Problems to be Solved

[0006] Aiming at the deficiencies of the prior art, the present invention provides a construction method for a foundation pit support structure, mainly to solve the problem that when the existing foundation pit support structure supports the foundation pit, the angle of its support plate cannot be changed. Therefore, when facing foundation pits with different slopes, it is not convenient to use, resulting in limitations in the use of the foundation pit support structure.

[0007] (II) Technical Solutions

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] A foundation pit support structure includes a bottom plate. Connecting plates are fixedly connected to both sides of the bottom plate. A rotating shaft is rotatably connected between the two connecting plates through bearings. A support plate is fixedly connected to the outer side of the rotating shaft. An avoidance groove is opened on the side of the support plate close to the bottom plate. A worm gear is key-connected to the outer side of the rotating shaft at a position within the avoidance groove. A round hole with one end open is opened in the bottom plate. A lead screw and a worm are rotatably connected in the round hole through bearings, and the lead screw is fixed to the worm. The worm is meshed with the worm gear. A support assembly for assisting in supporting the support plate is provided on the upper surface of the bottom plate. Installation holes are opened at the four corners of the bottom plate and the support plate, and fixing cones are fixedly connected in the installation holes.

[0010] Further, the support assembly includes a moving plate. Sliding grooves communicating with the round hole are opened at positions on both sides of the round hole in the bottom plate. A moving plate passing through the round hole is slidably connected in the sliding grooves. The lead screw passes through the moving plate and is threadedly connected to the moving plate. Two limiting grooves are opened on the upper surface of the bottom plate. The two limiting grooves communicate with the two sliding grooves respectively. Sliding seats moving along the groove direction of the limiting grooves are provided in the two limiting grooves, and the sliding seats are fixed to the moving plate. Connecting rods are rotatably connected in the two sliding seats through bearings. Two fixed seats are fixedly connected to one side of the support plate. The two connecting rods are respectively rotatably connected to the two fixed seats through bearings.

[0011] On the basis of the foregoing solution, rolling grooves are opened on both sides of the sliding seat, and balls are rollingly connected in the rolling grooves.

[0012] As a further solution of the present invention, a second locking nut is threadedly connected to the outer side of the lead screw at a position outside the bottom plate.

[0013] Further, two L-shaped baffle plates for resisting the support plate are fixedly connected to the upper surface of the bottom plate.

[0014] On the basis of the foregoing solution, an upwardly open installation port is opened in the fixing cone. A threaded rod is rotatably connected in the installation port through a bearing. Two trapezoidal blocks are threadedly connected to the outer side of the threaded rod. Dovetail grooves are opened at the slopes on both sides of the two trapezoidal blocks. Dovetail blocks are slidably connected in the dovetail grooves. A hexagonal pyramid passing through the fixing cone is opened on one side of the dovetail block, and an inclined surface fitting the slope of the trapezoidal block is provided at one end of the hexagonal pyramid. A guiding assembly for vertically moving the trapezoidal block up and down is provided in the installation port. A first locking nut is threadedly connected to the outer side of the threaded rod at a position on the top of the fixing cone.

[0015] As a further solution of the present invention, the guiding assembly includes two guiding grooves symmetrically opened in the installation port. Guide rods moving along the groove direction of the guiding grooves are fixedly connected to both sides of the two trapezoidal blocks.

[0016] The present invention also provides a construction method for a foundation pit support structure, which includes the following steps:

[0017] S1: Construction preparation, determining the on-site environment, establishing perfect protection measures, and cleaning the foundation pit;

[0018] S2: Installation, placing the bottom plate at the bottom of the foundation pit and inserting the fixing cones on the bottom plate into the soil;

[0019] S3: Foundation pit side wall support, rotating the lead screw, the lead screw will drive the worm to rotate, the worm will drive the worm wheel to rotate through meshing with the worm wheel, the worm wheel will drive the rotating shaft to rotate, the rotating shaft will drive the support plate to rotate towards the side wall of the foundation pit, so that the support plate rotates to an angle adapted to the slope of the side wall of the foundation pit, making the support plate fit the side wall of the foundation pit. At the same time, the fixing cones on the support plate will also be inserted into the soil. Then stop rotating the lead screw. At this time, the rotation angle of the support plate is fixed through the meshing of the worm and the worm wheel, so that the support plate supports the side wall of the foundation pit;

[0020] S4: Auxiliary support, during the rotation of the lead screw, the lead screw will make the moving plate move along the groove direction of the sliding groove through the thread meshing with the moving plate. The moving plate will drive the sliding seat to move along the limiting groove. At the same time, the connecting rod will rotate between the sliding seat and the fixed seat. And because the lead screw is fixed to the worm, the sliding seat will move synchronously with the support plate. After the lead screw stops rotating, at this time, the position of the moving plate is fixed through the thread meshing between the moving plate and the lead screw, so that the connecting rod supports the support plate;

[0021] S5: Locking, tightening the second locking nut to lock and fix the lead screw;

[0022] S6: Auxiliary fixation, rotating the threaded rod, the threaded rod will drive the trapezoidal block to move downward along the guide rod through the thread meshing with the trapezoidal block. During the downward movement of the trapezoidal block, it will push the hexagonal pyramid to move outward from the fixing cone through the cooperation of its own slope and the inclined plane of the hexagonal pyramid. At the same time, the dovetail block will move upward in the dovetail groove, so that the hexagonal pyramid is inserted into the soil.

[0023] (III) Beneficial effects

[0024] Compared with the prior art, the present invention provides a construction method for a foundation pit support structure, which has the following beneficial effects:

[0025] 1. By the combined use of the worm wheel and the worm, rotating the lead screw, the lead screw will drive the worm to rotate. The worm will drive the worm wheel to rotate through meshing with the worm wheel. The worm wheel will drive the rotating shaft to rotate. The rotating shaft will drive the support plate to rotate, thereby changing the angle of the support plate, enabling the support plate to support foundation pits with different slopes, and improving the applicability of the support structure.

[0026] 2. By setting the auxiliary support component, after changing the angle of the support plate, the auxiliary support component will assist in supporting the support plate, thereby avoiding the collapse of the side wall of the foundation pit caused by soft soil, which may harm the construction workers in the foundation pit and improving the safety of the support structure during use.

[0027] 3. By setting the hexagonal pyramid, when inserting the fixed cone into the soil to fix the support structure, the hexagonal pyramid extends out of the fixed cone and inserts into the soil, thereby increasing the stability of the fixed cone and improving the stability of the support structure during use. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is the flattened structural schematic diagram of the foundation pit support structure of a construction method of a foundation pit support structure proposed by the present invention;

[0029] Figure 2 is the three-dimensional structural schematic diagram of the foundation pit support structure of a construction method of a foundation pit support structure proposed by the present invention;

[0030] Figure 3 is the enlarged schematic diagram of the lead screw of the foundation pit support structure of a construction method of a foundation pit support structure proposed by the present invention.

[0031] Figure 4 is the enlarged sectional structural schematic diagram of the bottom plate of the foundation pit support structure of a construction method of a foundation pit support structure proposed by the present invention;

[0032] Figure 5 is the enlarged sectional structural schematic diagram of the fixed cone of the foundation pit support structure of a construction method of a foundation pit support structure proposed by the present invention;

[0033] Figure 6 is the enlarged structural schematic diagram of part A of the foundation pit support structure of a construction method of a foundation pit support structure proposed by the present invention;

[0034] Figure 7 is the flow structural schematic diagram of a construction method of a foundation pit support structure proposed by the present invention.

[0035] In the figure: 1, bottom plate; 2, limit groove; 3, sliding seat; 4, rotating shaft; 5, worm gear; 6, avoidance groove; 7, installation hole; 8, fixed cone; 9, support plate; 10, connecting plate; 11, L-shaped baffle; 12, first locking nut; 13, threaded rod; 14, connecting rod; 15, second locking nut; 16, lead screw; 17, worm; 18, moving plate; 19, fixed seat; 20, ball; 21, rolling groove; 22, sliding groove; 23, round hole; 25, trapezoidal block; 26, guiding groove; 27, guiding rod; 28, hexagonal pyramid; 29, dovetail block; 30, dovetail groove. Detailed implementation mode

[0036] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. The described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0037] Refer to Figures 1-7 , a foundation pit support structure, including a bottom plate 1. Connecting plates 10 are welded on both sides of the bottom plate 1. A rotating shaft 4 is rotatably connected between the two connecting plates 10 through bearings. A support plate 9 is welded on the outer side of the rotating shaft 4. An avoidance groove 6 is opened on the side of the support plate 9 close to the bottom plate 1. A worm gear 5 is key-connected to the position of the rotating shaft 4 located in the avoidance groove 6. The thickness of the connecting plate 10 is greater than that of the support plate 9. An open-ended circular hole 23 is opened in the bottom plate 1. A lead screw 16 and a worm 17 are rotatably connected in the circular hole 23 through bearings, and the lead screw 16 is fixed to the worm 17. The worm 17 meshes with the worm gear 5. Installation holes 7 are opened at the four corners of the bottom plate 1 and the support plate 9. Fixed cones 8 are welded in the installation holes 7. According to the attachment Figure 2 style, place the bottom plate 1 at the bottom of the foundation pit and insert the fixed cones 8 on the bottom plate 1 into the soil. Then rotate the lead screw 16. The lead screw 16 will drive the worm 17 to rotate. The worm 17 will drive the worm gear 5 to rotate through meshing with the worm gear 5. The worm gear 5 will drive the rotating shaft 4 to rotate. The rotating shaft 4 will drive the support plate 9 to rotate towards the side wall of the foundation pit, so that the support plate 9 rotates to an angle adapted to the slope of the side wall of the foundation pit, making the support plate 9 fit the side wall of the foundation pit. At the same time, the fixed cones 8 on the support plate 9 will also be inserted into the soil. Then stop rotating the lead screw 16. At this time, the rotation angle of the support plate 9 is fixed through the meshing of the worm 17 and the worm gear 5, so as to ensure that the support plate 9 supports the side wall of the foundation pit.

[0038] In the present invention, a support assembly for assisting in supporting the support plate 9 is provided on the upper surface of the bottom plate 1. The support assembly includes a moving plate 18. On both sides of the circular hole 23 inside the bottom plate 1, chutes 22 communicating with the circular hole 23 are provided. A moving plate 18 passing through the circular hole 23 is slidably connected inside the chute 22. A lead screw 16 passes through the moving plate 18 and is threadedly connected to the moving plate 18. Two limiting grooves 2 are provided on the upper surface of the bottom plate 1, and the two limiting grooves 2 are respectively communicated with the two chutes 22. Sliding seats 3 moving along the groove direction of the limiting grooves 2 are provided inside the two limiting grooves 2, and the sliding seats 3 are fixed to the moving plate 18. Two connecting rods 14 are rotatably connected inside the two sliding seats 3 through bearings. Two fixing seats 19 are welded on one side of the support plate 9, and the two connecting rods 14 are respectively rotatably connected to the two fixing seats 19 through bearings. During the rotation of the lead screw 16, the lead screw 16 will cause the moving plate 18 to move along the groove direction of the chute 22 through the threaded engagement with the moving plate 18. The moving plate 18 will drive the sliding seat 3 to move along the limiting groove 2. At the same time, the connecting rod 14 will rotate between the sliding seat 3 and the fixing seat 19. Since the lead screw 16 is fixed to the worm 17, the sliding seat 3 will move synchronously with the support plate 9. After the lead screw 16 stops rotating, at this time, the position of the moving plate 18 is fixed through the threaded engagement between the moving plate 18 and the lead screw 16, so that the connecting rod 14 supports the support plate 9, improving the strength of the support plate 9;

[0039] Particularly, rolling grooves 21 are provided on both sides of the sliding seat 3, and balls 20 are rotatably connected inside the rolling grooves 21. The balls 20 can reduce the friction of the movement of the sliding seat 3. A second locking nut 15 is threadedly connected to the outer side of the lead screw 16 at a position outside the bottom plate 1. The second locking nut 15 is tightened to lock and fix the lead screw 16, so that the lead screw 16 will not rotate, further improving the stability of the fixation of the support plate 9 and the moving plate 18. Two L-shaped baffles 11 for resisting the support plate 9 are welded on the upper surface of the bottom plate 1. Through the arrangement of the L-shaped baffles 11, the upward rotation angle of the support plate 9 is limited, so that the support plate 9 can only rotate upward to a state perpendicular to the bottom plate 1. When transporting the support structure, the support plate 9 is rotated to the attached Figure 1 style, so that the support plate 9 is horizontal with the bottom plate 1. At the same time, since the sliding seat 3 moves to the end of the limiting groove 2, the sliding seat 3 cannot move, so that the support plate 9 can only rotate downward to a state horizontal with the bottom plate 1, so that the support structure can be stacked and placed, facilitating the transportation of the support structure;

[0040] It should be specifically noted that an upward-opening installation port is provided in the fixed cone 8. A threaded rod 13 is rotatably connected in the installation port through a bearing. Two trapezoidal blocks 25 are threadedly connected to the outer side of the threaded rod 13. Dovetail grooves 30 are provided at the slopes on both sides of the two trapezoidal blocks 25. A dovetail block 29 is slidably connected in the dovetail groove 30. A hexagonal pyramid 28 passing through the fixed cone 8 is provided on one side of the dovetail block 29. And an inclined surface that fits the slope of the trapezoidal block 25 is provided at one end of the hexagonal pyramid 28. A guiding assembly for vertically moving the trapezoidal block 25 up and down is provided in the installation port. A first locking nut 12 is threadedly connected to the outer side of the threaded rod 13 at the position above the top of the fixed cone 8. The guiding assembly includes two guiding grooves 26, which are symmetrically provided in the installation port. Guide rods 27 that move along the groove direction of the guiding grooves 26 are welded to both sides of the two trapezoidal blocks 25. When the angle of the support plate 9 is adjusted, the threaded rod 13 is rotated. The threaded rod 13 will drive the trapezoidal block 25 to move downward along the guiding groove 26 through the guide rods 27 due to the threaded engagement with the trapezoidal block 25. During the downward movement of the trapezoidal block 25, the hexagonal pyramid 28 will be pushed out of the fixed cone 8 by the cooperation of its own slope and the inclined surface of the hexagonal pyramid 28. At the same time, the dovetail block 29 will move upward in the dovetail groove 30, so that the hexagonal pyramid 28 is inserted into the soil, thereby increasing the stability of the fixed cone 8 and improving the stability of the support structure during use. Then the first locking nut 12 is tightened to lock and fix the threaded rod 13, so as to stably fix the position of the trapezoidal block 25.

[0041] The present invention also provides a construction method for a foundation pit support structure, including the following steps:

[0042] S1: Construction preparation, determine the on-site environment, establish perfect protection measures, and clean the foundation pit;

[0043] S2: Installation, place the bottom plate 1 at the bottom of the foundation pit and insert the fixed cone 8 on the bottom plate 1 into the soil;

[0044] S3: Support for the foundation pit side wall, rotate the screw rod 16, the screw rod 16 will drive the worm 17 to rotate. The worm 17 will drive the worm gear 5 to rotate through the engagement with the worm gear 5. The worm gear 5 will drive the rotating shaft 4 to rotate. The rotating shaft 4 will drive the support plate 9 to rotate towards the side wall of the foundation pit, so that the support plate 9 rotates to an angle adapted to the slope of the foundation pit side wall, making the support plate 9 fit the side wall of the foundation pit. At the same time, the fixed cone 8 on the support plate 9 will also be inserted into the soil. Then stop rotating the screw rod 16. At this time, the rotation angle of the support plate 9 is fixed through the engagement of the worm 17 and the worm gear 5, so that the support plate 9 supports the side wall of the foundation pit;

[0045] S4: Auxiliary support. During the rotation of the lead screw 16, the lead screw 16 will cause the moving plate 18 to move along the groove direction of the sliding groove 22 through the thread engagement with the moving plate 18. The moving plate 18 will drive the sliding seat 3 to move along the limiting groove 2. At the same time, the connecting rod 14 will rotate between the sliding seat 3 and the fixed seat 19. Since the lead screw 16 is fixed to the worm 17, the sliding seat 3 will move synchronously with the support plate 9. After the lead screw 16 stops rotating, the position of the moving plate 18 will be fixed through the thread engagement between the moving plate 18 and the lead screw 16, so that the connecting rod 14 supports the support plate 9, improving the strength of the support plate 9;

[0046] S5: Locking. Tighten the second locking nut 15 to lock and fix the lead screw 16 so that the lead screw 16 will not rotate, further improving the stability of the fixation of the support plate 9 and the moving plate 18;

[0047] S6: Auxiliary fixation. Rotate the threaded rod 13. The threaded rod 13 will drive the trapezoidal block 25 to move downward along the guide rod 27 through the thread engagement with the trapezoidal block 25. During the downward movement of the trapezoidal block 25, the trapezoidal block 25 will push the hexagonal pyramid 28 to move outward of the fixed cone 8 through the cooperation of its own slope and the slope of the hexagonal pyramid 28. At the same time, the dovetail block 29 will move upward in the dovetail groove 30, so that the hexagonal pyramid 28 is inserted into the soil, improving the stability of the use of the support structure.

[0048] Working principle: When in use, according to the appendix Figure 2In the style described, place the bottom plate 1 at the bottom of the foundation pit and insert the fixing cone 8 on the bottom plate 1 into the soil. Subsequently, rotate the screw rod 16. The screw rod 16 will drive the worm 17 to rotate. The worm 17 will drive the worm wheel 5 to rotate through meshing with the worm wheel 5. The worm wheel 5 will drive the rotating shaft 4 to rotate. The rotating shaft 4 will drive the support plate 9 to rotate towards the side wall of the foundation pit, so that the support plate 9 rotates to an angle adapted to the slope of the side wall of the foundation pit, making the support plate 9 fit with the side wall of the foundation pit. At the same time, the fixing cone 8 on the support plate 9 will also be inserted into the soil. Then stop rotating the screw rod 16. At this time, the rotation angle of the support plate 9 is fixed through the meshing of the worm 17 and the worm wheel 5, so as to ensure that the support plate 9 supports the side wall of the foundation pit. During the rotation of the screw rod 16, the screw rod 16 will make the moving plate 18 move along the groove direction of the sliding groove 22 through the thread meshing with the moving plate 18. The moving plate 18 will drive the sliding seat 3 to move along the limiting groove 2. At the same time, the connecting rod 14 will rotate between the sliding seat 3 and the fixed seat 19. Since the screw rod 16 is fixed to the worm 17, the sliding seat 3 will move synchronously with the support plate 9. After the screw rod 16 stops rotating, at this time, the position of the moving plate 18 is fixed through the thread meshing between the moving plate 18 and the screw rod 16, so that the connecting rod 14 supports the support plate 9, improving the strength of the support plate 9. Then tighten the second locking nut 15 to lock and fix the screw rod 16, so that the screw rod 16 will not rotate, further improving the stability of the fixation of the support plate 9 and the moving plate 18. After the adjustment is completed, rotate the threaded rod 13. The threaded rod 13 will drive the trapezoidal block 25 to move downward along the guide rod 27 through the thread meshing with the trapezoidal block 25. During the downward movement of the trapezoidal block 25, it will push the hexagonal pyramid 28 to move outward from the fixing cone 8 through the cooperation of its own slope and the slope of the hexagonal pyramid 28, and at the same time, the dovetail block 29 will move upward in the dovetail groove 30, so that the hexagonal pyramid 28 is inserted into the soil, thereby increasing the stability of the fixing cone 8 and improving the stability of the use of the support structure. Then tighten the first locking nut 12 to lock and fix the threaded rod 13, so as to stably fix the position of the trapezoidal block 25.

[0049] In the description of this article, it should be noted that relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device.

[0050] In addition, although embodiments of the present invention have been shown and described, those of ordinary skill in the art will understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A foundation pit support structure, comprising a bottom plate (1), characterized in that, Both sides of the bottom plate (1) are fixedly connected with connecting plates (10). A rotating shaft (4) is rotatably connected between the two connecting plates (10) through bearings. A support plate (9) is fixedly connected to the outer side of the rotating shaft (4). An avoidance groove (6) is formed on the side of the support plate (9) close to the bottom plate (1). A worm gear (5) is key-connected to the outer side of the rotating shaft (4) at a position within the avoidance groove (6). A circular hole (23) with one end open is formed in the bottom plate (1). A lead screw (16) and a worm (17) are rotatably connected in the circular hole (23) through bearings, and the lead screw (16) is fixed to the worm (17). The worm (17) is meshed with the worm gear (5). A support assembly for assisting in supporting the support plate (9) is provided on the upper surface of the bottom plate (1). Mounting holes (7) are formed at the four corners of the bottom plate (1) and the support plate (9), and fixing cones (8) are fixedly connected in the mounting holes (7).

2. The retaining structure for foundation pit according to claim 1, wherein The support assembly includes a moving plate (18). Sliding grooves (22) communicating with the circular hole (23) are formed in the bottom plate (1) at positions on both sides of the circular hole (23). A moving plate (18) passing through the circular hole (23) is slidably connected in the sliding grooves (22). The lead screw (16) passes through the moving plate (18) and is threadedly connected to the moving plate (18). Two limiting grooves (2) are formed on the upper surface of the bottom plate (1). The two limiting grooves (2) communicate with the two sliding grooves (22) respectively. Slide seats (3) moving along the groove directions of the limiting grooves (2) are provided in the two limiting grooves (2), and the slide seats (3) are fixed to the moving plate (18). Connecting rods (14) are rotatably connected in the two slide seats (3) through bearings. Two fixing seats (19) are fixedly connected to one side of the support plate (9). The two connecting rods (14) are rotatably connected to the two fixing seats (19) through bearings respectively.

3. A foundation pit support structure according to claim 2, characterized in that, Rolling grooves (21) are formed on both sides of the slide seat (3), and balls (20) are rollably connected in the rolling grooves (21).

4. A foundation pit support structure according to claim 2, characterized in that, A second locking nut (15) is threadedly connected to the outer side of the lead screw (16) at a position outside the bottom plate (1).

5. A foundation pit support structure according to claim 1, characterized in that, Two L-shaped baffles (11) for resisting the support plate (9) are fixedly connected to the upper surface of the bottom plate (1).

6. A foundation pit support structure according to claim 1, characterized in that, An upwardly open mounting port is formed in the fixing cone (8). A threaded rod (13) is rotatably connected in the mounting port through a bearing. Two trapezoidal blocks (25) are threadedly connected to the outer side of the threaded rod (13). Dovetail grooves (30) are formed on the slopes on both sides of the two trapezoidal blocks (25). Dovetail blocks (29) are slidably connected in the dovetail grooves (30). A hexagonal pyramid (28) passing through the fixing cone (8) is formed on one side of the dovetail block (29), and an inclined surface fitting the slope of the trapezoidal block (25) is provided at one end of the hexagonal pyramid (28). A guiding assembly for vertically moving the trapezoidal block (25) up and down is provided in the mounting port. A first locking nut (12) is threadedly connected to the outer side of the threaded rod (13) at a position on the top of the fixing cone (8).

7. A foundation pit support structure according to claim 6, characterized in that, The guiding assembly includes two guiding grooves (26) symmetrically arranged in the installation opening. Guide rods (27) which move along the groove direction of the guiding grooves (26) are fixedly connected to both sides of the two trapezoidal blocks (25).

8. A construction method of a foundation pit support structure, characterized in that, It includes the following steps: S1: Construction preparation, determine the on-site environment, establish perfect protection measures, and clean the foundation pit; S2: Installation, place the bottom plate (1) at the bottom of the foundation pit and insert the fixing cones (8) on the bottom plate (1) into the soil; S3: Support for the side wall of the foundation pit. Rotate the lead screw (16), the lead screw (16) will drive the worm (17) to rotate. The worm (17) will drive the worm wheel (5) to rotate through meshing with the worm wheel (5). The worm wheel (5) will drive the rotating shaft (4) to rotate. The rotating shaft (4) will drive the support plate (9) to rotate towards the side wall of the foundation pit, so that the support plate (9) rotates to an angle adapted to the slope of the side wall of the foundation pit, and the support plate (9) fits with the side wall of the foundation pit. At the same time, the fixing cones (8) on the support plate (9) will also be inserted into the soil. Then stop rotating the lead screw (16). At this time, the rotation angle of the support plate (9) is fixed through the meshing of the worm (17) and the worm wheel (5), so that the support plate (9) supports the side wall of the foundation pit; S4: Auxiliary support. During the rotation of the lead screw (16), the lead screw (16) will make the moving plate (18) move along the groove direction of the sliding groove (22) through the thread meshing with the moving plate (18). The moving plate (18) will drive the sliding seat (3) to move along the limiting groove (2). At the same time, the connecting rod (14) will rotate between the sliding seat (3) and the fixed seat (19). Since the lead screw (16) is fixed to the worm (17), the sliding seat (3) will move synchronously with the support plate (9). After the lead screw (16) stops rotating, at this time, the position of the moving plate (18) is fixed through the thread meshing between the moving plate (18) and the lead screw (16), so that the connecting rod (14) supports the support plate (9); S5: Locking, tighten the second locking nut (15) to lock and fix the lead screw (16); S6: Auxiliary fixing, rotate the threaded rod (13), the threaded rod (13) will drive the trapezoidal block (25) to move downward along the guiding groove (26) through the thread meshing with the trapezoidal block (25). During the downward movement of the trapezoidal block (25), the trapezoidal block (25) will push the hexagonal pyramid (28) to move outward from the fixing cone (8) through the cooperation of its own slope and the slope of the hexagonal pyramid (28). At the same time, the dovetail block (29) will move upward in the dovetail groove (30), so that the hexagonal pyramid (28) is inserted into the soil.

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