Foundation pit supporting structure for water conservancy project

Abstract

The invention relates to a foundation pit supporting structure for hydraulic engineering, and belongs to the technical field of foundation pit supporting. Comprising a foundation pit body, a supporting plate arranged on the inner wall of the foundation pit body, a fixing piece arranged on the outer side of the foundation pit body and a connecting anchor cable connected between the supporting plate and the fixing piece. The fixing pieces are annularly arranged around the foundation pit body, each fixing piece comprises a plurality of outer supporting rods and a plurality of inner supporting rods arranged on the inner sides of the outer supporting rods, and the outer supporting rods are connected end to end to be in polygonal annular arrangement; the multiple inner supporting rods are arranged between every two adjacent outer supporting rods in a one-to-one correspondence mode and form a triangular area, and the connecting anchor cables are connected to the inner supporting rods. By means of the supporting system, the problems that in the prior art, a supporting system is complex in structure and single in supporting force direction, stress concentration is likely to be generated when the lateral pressure of a soil body is continuously increased, and consequently the supporting system loses efficacy or a supporting plate displaces are solved.

Description

Technical Field

[0001] The invention relates to a foundation pit supporting structure for water conservancy engineering, belonging to the technical field of foundation pit supporting. Background Art

[0002] The foundation pit support structure refers to a temporary or permanent support system adopted in construction projects to ensure the stability of the soil and the safety of the surrounding environment during the foundation pit excavation process. Its core function is to prevent soil collapse, control ground settlement, and protect adjacent buildings and underground pipelines. Common forms of foundation pit support mainly include: 1. Steel pile support, pile support, pile anchor, and pile cantilever; 2. Underground continuous wall support, ground-connected wall + support; 3. Cement retaining wall; 4. Soil nail wall, etc.

[0003] After searching, a Chinese patent with publication number CN117822600A discloses an anti-collapse foundation pit support structure, the technical key points of which are: it includes a base, rotating screws are arranged around the base, one end of the base close to the rotating screw is rotatably connected to a telescopic arm, one end of the telescopic arm is rotatably connected to an abutment baffle, and the rotating screw drives the telescopic arm to extend and retract, and a retraction device is arranged inside the abutment baffle; the retraction device includes: a movable baffle, the movable baffle is arranged inside the abutment baffle, and slides inside the movable baffle; a connecting plate, one end of the connecting plate is fixedly connected to the movable baffle, and a reaction force can be formed between the movable baffle and the abutment baffle through the connecting plate.

[0004] In the above scheme, the abutment baffle plate sunk into the soil on the side wall of the foundation pit can be taken out through the retraction device, which is convenient for the subsequent retraction work. However, there are still obvious limitations: the support system has a complex structure, many hinge points, and a single direction of support force. When the side pressure of the soil body continues to increase, stress concentration is easily generated, resulting in failure of the support system or displacement of the support plate.

[0005] Therefore, a new solution needs to be proposed to solve this problem. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a foundation pit support structure for water conservancy projects, which solves the problems in the prior art of complex support system structure, single support force direction, easy stress concentration when the soil side pressure continues to increase, resulting in failure of the support system or displacement of the support plate.

[0007] The technical problem to be solved by the present invention is achieved by adopting the following technical solutions: A foundation pit support structure for a water conservancy project, comprising a foundation pit body, a support plate arranged on the inner wall of the foundation pit body, a fixing member arranged on the outer side of the foundation pit body, and a connecting anchor cable connected between the support plate and the fixing member; The fixing part is arranged in a ring shape around the foundation pit body, and the fixing part includes a plurality of outer support rods and a plurality of inner support rods arranged on the inner side of the outer support rods, wherein the plurality of outer support rods are connected end to end and arranged in a polygonal ring shape, and the plurality of inner support rods are arranged one by one between two adjacent outer support rods and form a triangular area, and the connecting anchor cable is connected to the inner support rods.

[0008] The present invention is further configured as follows: a filter pipe is sleeved on the outside of the connecting anchor cable, one end of the filter pipe is fixedly connected to the inner support rod, and the other end of the filter pipe is connected to the support plate; The support plate comprises an inner support plate and an outer support plate, wherein the inner support plate is attached to the side wall of the foundation pit body, the inner support plate and the outer support plate are arranged at an interval, and the space between the inner support plate and the outer support plate is filled with filter sand and gravel; The other end of the filter pipe passes through the inner support plate and is fixedly connected to the outer support plate. The portion of the filter pipe located inside the side wall of the foundation pit body is provided with a first filter hole, and the portion of the filter pipe located between the inner support plate and the outer support plate is provided with a second filter hole. The first filter hole is opened at the top of the filter pipe, and the second filter hole is opened at the bottom of the filter pipe.

[0009] The present invention is further configured as follows: a support plate is fixedly connected to the bottom of the inner support plate, the support plate extends in a direction away from the side wall of the foundation pit body, the outer support plate is arranged on the top surface of the support plate, a plurality of drainage areas are provided on the support plate along the side length direction of the side wall of the foundation pit body, a plurality of evenly distributed drainage holes are provided in the drainage area, a drainage culvert extending along the circumferential direction thereof is provided at the bottom of the foundation pit body, and the drainage culvert corresponds to the support plate.

[0010] The present invention is further configured as follows: an elastic sheet is provided on the bottom surface of the support plate corresponding to the drainage area, the outer edge of the elastic sheet is fixedly connected to the support plate, a plurality of closed holes are opened on the elastic sheet, the plurality of closed holes and the plurality of drainage holes are staggered, and the elastic sheet closes the drainage holes when it is attached to the bottom surface of the support plate.

[0011] The present invention is further configured as follows: the triangular region is provided with pullback components located on the outer support rods on both sides, the inner support rod is a telescopic rod structure, the inner support rod comprises an extension rod, and sliding sleeves respectively slidably sleeved on both ends of the extension rod, and the ends of the sliding sleeves are respectively slidably connected to the inner sides of the outer support rods; The pullback assembly includes a sliding groove opened on the inner side of the outer support rod and extending along the length direction thereof, a fixed screw rod fixedly connected to the sliding groove, and a sliding block slidably connected to the sliding groove, and the sliding block is provided with a through hole that penetrates along the length direction thereof, the fixed screw rod is slidably inserted into the through hole, a driving shaft is rotatably connected in the sliding sleeve, an end of the driving shaft close to the sliding block is fixedly connected to the first bevel gear, an annular mounting groove is opened in the through hole, a second bevel gear is rotatably connected in the mounting groove, the second bevel gear is threadedly connected to the fixed screw rod and meshes with the first bevel gear, a connecting hole is opened at the end of the extension rod, one end of the driving shaft is slidably inserted in the connecting hole and is connected to the inner wall of the connecting hole by a spline; The filter pipe is fixedly connected to the outer wall of the sliding sleeve, one end of the connecting anchor cable is wound around the extension rod, a long groove is formed at the top of the filter pipe at the beginning of the inner support plate, a fixing block is provided on the inner support plate which is slidably connected to the long groove and extends into the interior of the filter pipe, and the other end of the connecting anchor cable is fixedly connected to the fixing block.

[0012] The present invention is further configured as follows: a reinforcing rod is provided between the sliding sleeve and the outer support rod, one end of the reinforcing rod is fixedly connected to the sliding sleeve, a sliding rail is fixedly connected to the inner side of the outer support rod, and the other end of the reinforcing rod is slidably connected to the sliding rail.

[0013] The present invention is further configured as follows: a plurality of filter pipes are respectively provided on both sides of the center line of the support plate, one end of the plurality of filter pipes are uniformly distributed laterally along the support plate, the other ends of the plurality of filter pipes are interconnected and fixedly connected to the sliding sleeve, and a connecting anchor cable is provided in each of the filter pipes.

[0014] The present invention is further configured as follows: a protective shell is provided on the outside of the triangular area, and an extension groove extending along the moving direction of the inner support rod is opened on the protective shell at a position corresponding to the connecting anchor cable.

[0015] The beneficial effects of the present invention are: 1. The fixings are made of external support rods connected end to end to form a polygonal ring frame, and internal support rods are arranged between adjacent external support rods to form a triangular rigid unit. When the soil pressure of the side wall of the foundation pit acts on the support plate, the force is transmitted to the internal support rods through the connecting anchor cables. The triangular area decomposes the oblique tension into tensile / compressive loads and lateral shear loads along the axial direction of the external support rods, forming a spatial truss effect. The polygonal ring frame provides annular restraint to resist the lateral expansion of the soil; the triangular unit enhances the bending stiffness of the node and avoids stress concentration in the traditional single-rod hinged structure; it does not occupy the internal space of the foundation pit body, which is convenient for construction; 2. By setting up the filter pipe and connecting the anchor cable, not only the pulling force on the support plate is enhanced, but also the groundwater enters the pipe through the first filter hole → flows along the pipe to the gravel layer → penetrates into the gap between the gravel through the second filter hole → flows into the bottom drainage channel through the drainage hole of the support plate, so that the drainage path is integrated with the support structure; 3. By setting the drainage hole and the elastic sheet together, when the water level of the drainage culvert is lower than the support plate, the elastic sheet sags due to its own weight, the closed hole and the drainage hole are opened in a staggered manner, and water flows through; when the water level of the drainage culvert rises during precipitation, the water pressure pushes the elastic sheet to cling to the bottom surface of the support plate, and the closed hole completely covers the drainage hole to block the backflow; 4. By setting up a pullback assembly, when the side wall of the foundation pit collapses, the inner support plate is pulled back by force to connect the anchor cable, driving the extension rod to rotate, so that the inner support rod moves away from the foundation pit body, and the outer support plate is pulled back through the filter pipe, so that the overall support system is stable; 5. By setting up several filter pipes on each side, the connecting anchor cables are radially connected to different points of the inner support plate. When a single anchor cable fails, the adjacent anchor cables share the load through the rigid force transmission of the support plate. The extension groove at the bottom of the protective shell allows the filter pipe to deflect and adapt to the uneven settlement of the soil; 6. This solution realizes the dispersed load-bearing of the space truss, the active release of water-stopping and drainage, and the dynamic balance of mechanical compensation through the triple coordination of the rigid support frame of the fixing parts, the drainage and pressure reduction of the filter pipe, and the adaptive adjustment of the pullback component. Compared with the traditional support structure, the overall safety factor is greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0017] Figure 2 It is a partial perspective view of the present invention.

[0018] Figure 3 yes Figure 2 A partial enlarged view of part A.

[0019] Figure 4 yes Figure 2 A partial enlarged view of part B.

[0020] Figure 5 It is a schematic structural diagram of the fixing parts and the enclosure plate parts after the foundation pit body is removed in the present invention.

[0021] Figure 6 yes Figure 5 A partial enlarged view of part C.

[0022] In the figure: 1. foundation pit body; 2. fixing parts; 3. connecting anchor cable; 4. outer support rod; 5. inner support rod; 6. filter pipe; 7. inner support plate; 8. outer support plate; 9. support plate; 10. filter sand and gravel; 11. first filter hole; 12. second filter hole; 13. drainage hole; 14. drainage culvert; 15. elastic sheet; 16. closed hole; 17. pullback assembly; 18. extension rod; 19. sliding sleeve; 20. reinforcement rod; 21. slide rail; 22. sliding groove; 23. fixed screw; 24. slider; 25. perforation; 26. drive shaft; 27. first bevel gear; 28. mounting groove; 29. ​​second bevel gear; 30. connecting hole; 31. spline; 32. long groove; 33. fixing block; 34. protective shell; 35. extension groove. DETAILED DESCRIPTION

[0023] In order to make the technical means, creative features, objectives and effects of the present invention easier to understand, the present invention is further described below with reference to specific illustrations.

[0024] like Figure 1-Figure 6 As shown, a foundation pit support structure for a water conservancy project includes a foundation pit body 1, a support plate arranged on the inner wall of the foundation pit body 1, a fixing member 2 arranged on the outer side of the foundation pit body 1, and a connecting anchor cable 3 connected between the support plate and the fixing member 2, wherein the fixing member 2 is arranged in a ring shape around the foundation pit body 1, and the fixing member 2 includes a plurality of outer support rods 4 and a plurality of inner support rods 5 arranged on the inner side of the outer support rods 4, wherein the plurality of outer support rods 4 are connected end to end and arranged in a polygonal ring shape, and the plurality of inner support rods 5 are arranged one by one between two adjacent outer support rods 4 and form a triangular area. The connecting anchor cable 3 is connected to the inner support rod 5, and a filter pipe 6 is sleeved on the outside of the connecting anchor cable 3, one end of the filter pipe 6 is fixedly connected to the inner support rod 5, and the other end of the filter pipe 6 is connected to the support plate.

[0025] A plurality of filter pipes 6 are respectively provided on both sides of the center line of the support plate, one ends of the plurality of filter pipes 6 are uniformly distributed laterally along the support plate, the other ends of the plurality of filter pipes 6 are interconnected and fixedly connected to the inner support rod 5, and a connecting anchor cable 3 is provided in each filter pipe 6. By arranging a plurality of filter pipes 6 on each side, the connecting anchor cables 3 are radially connected to different points of the support plate. When a single anchor cable fails, the adjacent anchor cables share the load through the rigid force transmission of the support plate.

[0026] Among them, the support plate includes an inner support plate 7 and an outer support plate 8. The inner support plate 7 is attached to the side wall of the foundation pit body 1. The inner support plate 7 and the outer support plate 8 are arranged at intervals. A support plate 9 is fixedly connected to the bottom of the inner support plate 7. The support plate 9 extends in a direction away from the side wall of the foundation pit body 1. The outer support plate 8 is arranged on the top surface of the support plate 9. Filter sand and gravel 10 is filled between the inner support plate 7 and the outer support plate 8.

[0027] One end of the filter pipe 6 away from the inner support rod 5 passes through the inner support plate 7 and is fixedly connected to the outer support plate 8. The part of the filter pipe 6 located inside the side wall of the foundation pit body 1 is provided with a first filter hole 11, and the part of the filter pipe 6 located between the inner support plate 7 and the outer support plate 8 is provided with a second filter hole 12. The first filter hole 11 is opened at the top of the filter pipe 6, and the second filter hole 12 is opened at the bottom of the filter pipe 6.

[0028] In order to facilitate drainage of the foundation pit body 1, a plurality of drainage areas are provided on the support plate 9 along the length direction of the side wall of the foundation pit body 1, and a plurality of evenly distributed drainage holes 13 are provided in the drainage area. A drainage culvert 14 extending along the circumferential direction is provided at the bottom of the foundation pit body 1, and the drainage culvert 14 corresponds to the support plate 9. By setting the filter pipe 6 and the connecting anchor cable 3, not only the pulling force on the support plate is enhanced, but also the groundwater enters the pipe through the first filter hole 11 → flows along the pipe to the gravel layer → penetrates into the gap between the gravel through the second filter hole 12 → flows into the bottom drainage culvert 14 through the drainage hole 13 of the support plate 9, so that the drainage path is integrated with the support structure.

[0029] The bottom surface of the support plate 9 is provided with an elastic sheet 15 corresponding to the drainage area. The outer edge of the elastic sheet 15 is fixedly connected to the support plate 9. The elastic sheet 15 is provided with a plurality of closed holes 16. The plurality of closed holes 16 are arranged in a staggered manner with the plurality of drainage holes 13. The elastic sheet 15 closes the drainage holes 13 when it is attached to the bottom surface of the support plate 9. By arranging the drainage holes 13 and the elastic sheet 15 in coordination, during drainage, when the water level of the drainage culvert 14 is lower than the support plate 9, the elastic sheet 15 sags due to its own weight, the closed holes 16 and the drainage holes 13 are opened in a misaligned manner, and water flows through; during precipitation, when the water level of the drainage culvert 14 rises, the water pressure pushes the elastic sheet 15 to be close to the bottom surface of the support plate 9, and the closed holes 16 completely cover the drainage holes 13, blocking backflow.

[0030] In order to ensure the stability of the support plate, the triangular area of ​​the fixing member 2 is respectively provided with a pullback assembly 17 located at the outer support rods 4 on both sides, and the inner support rod 5 is a telescopic rod structure. The inner support rod 5 includes an extension rod 18 and sliding sleeves 19 respectively slidably sleeved at both ends of the extension rod 18. The extension rod 18 and the sliding sleeve 19 are rotationally matched, and the ends of the sliding sleeve 19 are respectively slidably connected to the inner side of the outer support rod 4. A reinforcing rod 20 is provided between the sliding sleeve 19 and the outer support rod 4, one end of the reinforcing rod 20 is fixedly connected to the sliding sleeve 19, and a slide rail 21 is fixedly connected to the inner side of the outer support rod 4, and the other end of the reinforcing rod 20 is slidably connected to the slide rail 21.

[0031] The pullback assembly 17 includes a sliding groove 22 provided on the inner side of the outer support rod 4 and extending along the length direction thereof, a fixed screw rod 23 fixedly connected to the sliding groove 22, and a slider 24 slidably connected to the sliding groove 22. The slider 24 is provided with a through hole 25 penetrating along the length direction thereof. The fixed screw rod 23 is slidably penetrated in the through hole 25. One end of the fixed sleeve is fixedly connected to the slider 24. A driving shaft 26 is rotatably connected in the sliding sleeve 19. One end of the driving shaft 26 close to the slider 24 is fixedly connected to a first bevel gear 27. An annular mounting groove 28 is provided in the through hole 25. A second bevel gear 29 is rotatably connected in the mounting groove 28. The second bevel gear 29 is threadedly connected to the fixed screw rod 23 and meshed with the first bevel gear 27. A connecting hole 30 is provided at the end of the extension rod 18. One end of the driving shaft 26 is slidably inserted in the connecting hole 30 and connected to the inner wall of the connecting hole 30 through a spline 31. The filter pipe 6 is fixedly connected to the outer wall of the sliding sleeve 19, one end of the connecting anchor cable 3 is wound around the extension rod 18, a long groove 32 is formed at the top of the filter pipe 6 at the inner support plate 7, a fixing block 33 is provided on the inner support plate 7, which is slidably connected to the long groove 32 and extends into the filter pipe 6, and the other end of the connecting anchor cable 3 is fixedly connected to the fixing block 33. A protective shell 34 is provided on the outer cover of the triangular area, and an extension groove 35 extending along the moving direction of the inner support rod 5 is provided on the protective shell 34 corresponding to the position of the connecting anchor cable 3.

[0032] By setting up the pullback assembly 17, when the side wall of the foundation pit body 1 collapses, the inner support plate 7 is pulled back by force to connect the anchor cable 3, driving the extension rod 18 to rotate, so that the inner support rod 5 moves away from the foundation pit body 1, and the outer support plate 8 is pulled back through the filter pipe 6, so that the overall support system is stable.

[0033] The implementation principle of the present invention is: The fixing part 2 uses an outer support rod 4 connected end to end to form a polygonal ring frame, and an inner support rod 5 is arranged between adjacent outer support rods 4 to form a triangular rigid unit. When the soil pressure of the side wall of the foundation pit acts on the support plate, the force is transmitted to the inner support rod 5 through the connecting anchor cable 3. The triangular area decomposes the oblique tension into a tensile / compressive load and a lateral shear load along the axial direction of the outer support rod 4, forming a spatial truss effect. The polygonal ring frame provides annular constraint force to resist the lateral expansion of the soil; the triangular unit enhances the bending stiffness of the node and avoids stress concentration in the traditional single-rod hinged structure; it does not occupy the internal space of the foundation pit body 1, which is convenient for construction.

[0034] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of the present invention is defined by the attached claims and their equivalents.

Claims

1. A foundation pit support structure for water conservancy projects, characterized in that: It comprises a foundation pit body (1), a supporting plate arranged on the inner wall of the foundation pit body (1), a fixing member (2) arranged on the outer side of the foundation pit body (1), and a connecting anchor cable (3) connected between the supporting plate and the fixing member (2); The fixing member (2) is arranged in a ring shape around the foundation pit body (1), and the fixing member (2) comprises a plurality of outer support rods (4) and a plurality of inner support rods (5) arranged inside the outer support rods (4), wherein the plurality of outer support rods (4) are connected end to end and arranged in a polygonal ring shape, and the plurality of inner support rods (5) are arranged one by one between two adjacent outer support rods (4) to form a triangular area, and the connecting anchor cable (3) is connected to the inner support rod (5).

2. A foundation pit support structure for water conservancy engineering according to claim 1, characterized in that: The connecting anchor cable (3) is externally sleeved with a filter pipe (6), one end of the filter pipe (6) is fixedly connected to the inner support rod (5), and the other end of the filter pipe (6) is connected to the support plate; The support plate comprises an inner support plate (7) and an outer support plate (8), the inner support plate (7) is attached to the side wall of the foundation pit body (1), the inner support plate (7) and the outer support plate (8) are arranged at a distance, and filtering sand and gravel (10) are filled between the inner support plate (7) and the outer support plate (8); The other end of the filter pipe (6) passes through the inner supporting plate (7) and is fixedly connected to the outer supporting plate (8); a first filter hole (11) is provided in the portion of the filter pipe (6) located inside the side wall of the foundation pit body (1); a second filter hole (12) is provided in the portion of the filter pipe (6) located between the inner supporting plate (7) and the outer supporting plate (8); the first filter hole (11) is provided at the top of the filter pipe (6), and the second filter hole (12) is provided at the bottom of the filter pipe (6).

3. A foundation pit support structure for water conservancy engineering according to claim 2, characterized in that: A support plate (9) is fixedly connected to the bottom of the inner support plate (7), and the support plate (9) extends in a direction away from the side wall of the foundation pit body (1). The outer support plate (8) is arranged on the top surface of the support plate (9). A plurality of drainage areas are arranged on the support plate (9) along the length direction of the side wall of the foundation pit body (1), and a plurality of evenly distributed drainage holes (13) are arranged in the drainage areas. A drainage culvert (14) extending in a circumferential direction is arranged at the bottom of the foundation pit body (1), and the drainage culvert (14) corresponds to the support plate (9).

4. A foundation pit support structure for water conservancy engineering according to claim 3, characterized in that: An elastic sheet (15) is provided on the bottom surface of the support plate (9) corresponding to the drainage area. The outer edge of the elastic sheet (15) is fixedly connected to the support plate (9). A plurality of closed holes (16) are provided on the elastic sheet (15). The plurality of closed holes (16) and the plurality of drainage holes (13) are arranged in a staggered manner. When the elastic sheet (15) is attached to the bottom surface of the support plate (9), the drainage holes (13) are closed.

5. A foundation pit support structure for water conservancy engineering according to claim 2, characterized in that: The triangular region is provided with pullback components (17) located on the outer support rods (4) on both sides, the inner support rod (5) is a telescopic rod structure, the inner support rod (5) comprises an extension rod (18), and sliding sleeves (19) respectively slidably mounted on both ends of the extension rod (18), and the ends of the sliding sleeves (19) are respectively slidably connected to the inner sides of the outer support rods (4); The pullback assembly (17) comprises a sliding groove (22) provided on the inner side of the outer support rod (4) and extending along the length direction thereof, a fixed screw rod (23) fixedly connected to the sliding groove (22), and a slider (24) slidably connected to the sliding groove (22), wherein the slider (24) is provided with a through hole (25) extending along the length direction thereof, the fixed screw rod (23) is slidably inserted into the through hole (25), and a driving shaft (26) is rotatably connected to the sliding sleeve (19), and the driving shaft (26) is close to the slider (2 4), one end of which is fixedly connected to a first bevel gear (27), an annular mounting groove (28) is provided in the through hole (25), a second bevel gear (29) is rotatably connected in the mounting groove (28), the second bevel gear (29) is threadedly connected to the fixed screw rod (23) and meshed with the first bevel gear (27), a connecting hole (30) is provided at the end of the extension rod (18), one end of the drive shaft (26) is slidably inserted into the connecting hole (30) and connected to the inner wall of the connecting hole (30) via a spline (31); The filter pipe (6) is fixedly connected to the outer wall of the sliding sleeve (19), one end of the connecting anchor cable (3) is wound around the extension rod (18), a long groove (32) is formed at the top of the filter pipe (6) at the beginning of the inner support plate (7), a fixing block (33) is provided on the inner support plate (7) and is slidably connected to the long groove (32) and extends into the interior of the filter pipe (6), and the other end of the connecting anchor cable (3) is fixedly connected to the fixing block (33).

6. A foundation pit support structure for water conservancy engineering according to claim 5, characterized in that: A reinforcing rod (20) is provided between the sliding sleeve (19) and the outer support rod (4); one end of the reinforcing rod (20) is fixedly connected to the sliding sleeve (19); a sliding rail (21) is fixedly connected to the inner side of the outer support rod (4); and the other end of the reinforcing rod (20) is slidably connected to the sliding rail (21).

7. A foundation pit support structure for water conservancy engineering according to claim 5, characterized in that: A plurality of filter pipes (6) are respectively arranged on both sides of the center line of the support plate, one end of the plurality of filter pipes (6) is evenly distributed along the horizontal direction of the support plate, the other ends of the plurality of filter pipes (6) are interconnected and fixedly connected to the sliding sleeve (19), and a connecting anchor cable (3) is arranged in each of the filter pipes (6).

8. The foundation pit support structure for water conservancy engineering according to claim 5, characterized in that: The triangular area is covered externally with a protective shell (34), and the protective shell (34) is provided with an extension groove (35) extending along the moving direction of the inner support rod (5) at a position corresponding to the connecting anchor cable (3).

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