A large underground pipeline foundation pit support structure

Abstract

The application discloses a large-scale underground pipeline foundation pit supporting structure which comprises outer sheath assembly one and outer sheath assembly two. The outer walls of the outer sheath assembly one are provided with flange fixing plates one, the outer walls of the outer sheath assembly two are provided with flange fixing plates two, and the outer sheath assembly two is connected with the flange fixing plates one through bolts. The outer walls of the bottom of the outer sheath assembly one are fixedly connected with a plurality of U-shaped bases through bolts at equal distances, and the top end of each U-shaped base is provided with a protective cover. The device is provided with U-shaped bases and protective covers, can support and protect the soil pressure of the sidewall and the upper part of the underground pipeline foundation pit, and can protect underground pipelines with different diameters and sizes through the outer sheath assembly one and the outer sheath assembly two. The device can avoid damaging the underground pipelines during the construction of the foundation pit, and can keep the underground pipelines in a sealed and dry state, thereby prolonging the service life of the underground pipelines.

Description

Technical Field

[0001] This invention belongs to the field of foundation pit support technology, specifically relating to a foundation pit support structure that spans large underground pipelines. Background Technology

[0002] Underground pipelines refer to the pipelines and ancillary facilities for water supply, drainage, gas, heating, electricity, communications, radio and television broadcasting, and industry within a city. They are important infrastructure and "lifelines" for ensuring the operation of a city.

[0003] Chinese patent application CN202020950941.2 discloses a support structure for a foundation pit spanning a large underground pipeline, mainly composed of front piles, rear piles, and a reverse-construction retaining plate. The reverse-construction retaining plate is constructed using a reverse method, ensuring the stability of the soil on the pit sidewalls during excavation and transferring the horizontal earth pressure of the missing pile section to the connected support piles. The front pile cap beam, rear pile cap beam, crossbeams, and inter-beam slab are integrally cast and fixed together to form a platform slab with high planar stiffness. This, in turn, allows the front and rear piles to form a spatial rigid frame structure with high lateral stiffness, jointly bearing the enormous horizontal earth pressure of the missing pile section at the underground pipeline location. This application describes a support structure with high local stiffness, strong bending and shear resistance, solving the problem of support difficulties caused by the inability to install support piles at locations with large underground pipelines (i.e., missing pile positions) in foundation pit support. It ensures the stability and safety of the foundation pit sidewalls at locations with large underground pipelines. However, it has the following drawback: while it provides excellent support for the foundation pit, it cannot protect underground pipelines, making them susceptible to damage and significantly reducing their service life. This phenomenon has become a problem that urgently needs to be solved by those in the field. Summary of the Invention

[0004] The purpose of this invention is to provide a support structure for foundation pits spanning large underground pipelines, in order to solve the problems mentioned in the background art.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a support structure for a foundation pit spanning a large underground pipeline, comprising an outer sheath assembly one and an outer sheath assembly two. The outer sheath assembly one has flanged fixing plates one on each side of its outer wall, and the outer sheath assembly two has flanged fixing plates two on each side of its outer wall. Both outer sheath assemblies two are connected to the flanged fixing plates one by bolts. The bottom outer wall of the outer sheath assembly one is fixedly connected with multiple U-shaped bases at equal intervals by bolts, and each U-shaped base has a protective cover at its top. The bottom of the outer sheath assembly one... The inner wall is provided with multiple pairs of arc-shaped grooves at equal intervals, and a placement plate is provided between each pair of arc-shaped grooves. A slider is slidably connected to the inner wall of each arc-shaped groove, and a connecting spring is fixedly connected between the slider and the inner wall of each arc-shaped groove. A connecting plate is hinged between the slider and the placement plate. A traction rope is fixedly connected to the top outer wall of each slider, and a pulling mechanism is provided at the top of each traction rope. Multiple arc-shaped blocks are provided at equal intervals on the bottom inner wall of the outer sheath assembly two, and a connecting spring is fixedly connected between the top outer wall of each arc-shaped block and the top inner wall of the outer sheath assembly two.

[0006] The present invention further describes that the pulling mechanism includes a winding column, one end of which is rotatably connected to the inner wall of one side of the outer sheath assembly, and a plurality of protrusions are fixedly connected to the outer wall of the winding column, and the outer walls of the plurality of protrusions are slidably connected to the same turntable.

[0007] The present invention further describes that a limiting plate is fixedly connected to one side of the outer wall of each of the protrusions, and the other end of the multiple protrusions is fixedly connected to the same limiting disc.

[0008] The present invention further describes that a plurality of positioning plates are fixedly connected to the top outer wall of the turntable, and a positioning post is provided in the gap between two of the positioning plates. One end of the positioning post is fixedly connected to the inner wall of one side of the outer sheath assembly. A plurality of connecting springs are provided between the turntable and the limiting plate. When the turntable is in close contact with the limiting plate, one end of the positioning post slightly extends beyond the turntable.

[0009] The present invention further describes that each of the U-shaped bases has an installation cavity on both sides of its top end, and a telescopic plate is slidably connected to the top of each installation cavity. The top end of the telescopic plate is hinged to the bottom outer wall of the protective cover, and a lifting plate is fixedly connected to the bottom end of the telescopic plate.

[0010] The present invention further describes that a sliding groove is formed on one side of the outer wall of the mounting cavity, and a pressing plate one and a pressing plate two are slidably connected to the upper and lower inner walls of the sliding groove, respectively. The bottom outer wall of the pressing plate one is in contact with the flange fixing plate two, and the top outer wall of the pressing plate two is in contact with the flange fixing plate one.

[0011] The present invention further describes that a rack is fixedly connected to one side of the outer wall of both the first pressing plate and the second pressing plate, and the rack is slidably connected to the inner wall of the mounting cavity. A fixing post is provided between the two racks, and the two ends of the fixing post are rotatably connected to the inner wall of the mounting cavity. A gear is fixedly connected to the outer wall of the middle part of the fixing post, and the gear meshes with the racks on both sides. The bottom outer wall of the lifting plate contacts the rack located above.

[0012] The present invention further describes that a sealing groove is formed on the outer wall of the top side of the first flange fixing plate, and a sealing block is fixedly connected to the outer wall of the bottom side of the second flange fixing plate, and the sealing block and the sealing groove are in the same vertical plane.

[0013] The present invention further describes that a plurality of connecting springs are fixedly connected to the inner wall of the bottom of the sealing groove, and the top of each of the plurality of connecting springs is fixedly connected to the same sealing gasket.

[0014] Compared with the prior art, the beneficial effects achieved by the present invention are: the present invention,

[0015] This invention, by setting a U-shaped base and a protective cover, can support and protect the soil pressure on the side wall and above of the underground pipeline pit. Furthermore, by setting an outer sheath assembly one and an outer sheath assembly two, it can protect underground pipelines of different diameters, preventing damage to the underground pipelines during the construction process of the pit, while keeping the underground pipelines in a sealed and dry state, thus improving the service life of the underground pipelines.

[0016] When the outer wall of the top of the protective cover is subjected to external force, it will press the telescopic plate, causing it to retract into the mounting cavity inside the U-shaped base. At the same time, the telescopic plate presses the first pressing plate in the sliding groove downward through the lifting plate. Through the meshing transmission of the rack and gear, the second pressing plate below the sliding groove moves upward, causing the first pressing plate and the second pressing plate to come closer to each other. This allows force to be applied to the first and second flange fixing plates between the first and the second pressing plates, making them fit more tightly and greatly improving the sealing effect.

[0017] By setting a sealing block, a sealing groove, a sealing gasket, and a connecting spring four, when outer sheath assembly one and outer sheath assembly two are fixedly connected, the sealing block on the bottom outer wall of the flange fixing plate two will be embedded into the sealing groove of flange fixing plate one. At the same time, through the elastic force of connecting spring four, the sealing gasket in sealing groove four will be tightly attached to the bottom end of the sealing block, thereby further and effectively improving the sealing effect between outer sheath assembly one and outer sheath assembly two. Attached Figure Description

[0018] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0019] Figure 1 This is a schematic diagram of a support structure for a foundation pit spanning a large underground pipeline, as proposed in Example 1.

[0020] Figure 2 This is a schematic diagram of the outer sheath assembly of a foundation pit support structure spanning a large underground pipeline, as proposed in Example 1.

[0021] Figure 3 Example 1 illustrates a support structure for a foundation pit spanning a large underground pipeline. Figure 2 Enlarged schematic diagram of the structure at point A in the middle;

[0022] Figure 4 This is a schematic diagram of a wound column structure for a foundation pit support structure spanning a large underground pipeline, as proposed in Example 1.

[0023] Figure 5 This is a schematic diagram of the outer sheath component two of the foundation pit support structure for crossing a large underground pipeline proposed in Example 1;

[0024] Figure 6 This is a side view of a support structure for a foundation pit spanning a large underground pipeline, as proposed in Example 2.

[0025] Figure 7 This is a cross-sectional view of the U-shaped base of a support structure for a foundation pit spanning a large underground pipeline, as proposed in Example 2.

[0026] Figure 8 This is a cross-sectional schematic diagram of the flanged fixing plate one and flanged fixing plate two of the foundation pit support structure for crossing a large underground pipeline proposed in Example 3.

[0027] In the diagram: 1. Outer sheath assembly one; 2. U-shaped base; 3. Outer sheath assembly two; 4. Protective cover; 5. Placement plate; 6. Flanged fixing plate one; 7. Arc-shaped slide groove; 8. Slider; 9. Traction rope; 10. Positioning post; 11. Winding post; 12. Turntable; 13. Connecting plate; 14. Connecting spring one; 15. Limiting plate; 16. Positioning plate; 17. Connecting spring two; 18. Protrusion; 19. Limiting disc; 20. Flanged fixing plate two; 21. Connecting spring three; 22. Arc-shaped block; 23. Telescopic plate; 24. Rack; 25. Fixing post; 26. Gear; 27. Lifting plate; 28. Mounting cavity; 29. ​​Sliding groove; 30. Pressing plate one; 31. Pressing plate two; 32. Sealing groove; 33. Sealing block; 34. Sealing gasket; 35. Connecting spring four. Detailed Implementation

[0028] The following detailed, non-limiting description of the technical solution of the present invention, in conjunction with preferred embodiments and accompanying drawings, is provided. Obviously, the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention. Example 1

[0029] Please see Figure 1-5This invention provides a technical solution: a support structure for a foundation pit spanning a large underground pipeline, comprising an outer sheath assembly 1 and an outer sheath assembly 2 3. The outer walls of the outer sheath assembly 1 are provided with flanged fixing plates 6 on both sides, and the outer walls of the outer sheath assembly 2 3 are provided with flanged fixing plates 20 on both sides. The outer sheath assembly 2 3 is connected to the flanged fixing plates 6 by bolts. Multiple U-shaped bases 2 are fixedly connected to the bottom outer wall of the outer sheath assembly 1 at equal intervals by bolts, and each U-shaped base 2 has a protective cover 4 at its top. Multiple pairs of arc-shaped grooves 7 are provided at equal intervals on the bottom inner wall of the outer sheath assembly 1, and a placement plate 5 is provided between each pair of arc-shaped grooves 7. The inner wall of the 7th arc-shaped groove is slidably connected to a slider 8, and a connecting spring 14 is fixedly connected between the slider 8 and the inner wall of the arc-shaped groove 7. A connecting plate 13 is hinged between the slider 8 and the placement plate 5. A traction rope 9 is fixedly connected to the top outer wall of the slider 8, and a pulling mechanism is provided at the top of the traction rope 9. Multiple arc-shaped blocks 22 are evenly arranged on the bottom inner wall of the outer sheath assembly 2 3, and a connecting spring 3 21 is fixedly connected between the top outer wall of each arc-shaped block 22 and the top inner wall of the outer sheath assembly 2 3. Multiple U-shaped bases 2 are placed in the foundation pit for installing the bottom line pipeline. Then, the outer sheath assembly 1 is fixed to the multiple U-shaped bases 2 with bolts. Then, the pulling mechanism is used to fix the outer sheath assembly 1 to the multiple U-shaped bases 2. Force is applied to the traction rope 9, causing it to pull the slider 8 inside the arc-shaped chute 7 upwards along the chute 7. This stretches the connecting spring 14 on one side of the outer wall of the slider 8. As the slider 8 moves, the tilt angle of the placement plate 5 can be adjusted via the connecting plate 13 on its outer wall. After adjusting the multiple placement plates 5 to a suitable angle according to the diameter of the underground pipeline, the underground pipeline is placed in the outer sheath assembly 1. Then, the outer sheath assembly 2 3 is placed on top of the outer sheath assembly 1 1, so that the multiple arc-shaped blocks 22 on the bottom inner wall of the outer sheath assembly 2 3 contact the outer wall of the underground pipeline. Thus, under the rebound force of the multiple connecting springs 21, force is applied to the outer wall of the underground pipeline. Then, the flange fixing plate 1 6 and flange fixing plate 20 are aligned and fixed together with multiple bolts. Through the cooperation of multiple arc blocks 22 and placement plate 5, the underground pipeline can be firmly fixed in the outer sheath assembly 1 and outer sheath assembly 2 3. By setting the U-shaped base 2 and protective cover 4, the soil pressure on the side wall and above of the underground pipeline pit can be supported and protected. Furthermore, by setting the outer sheath assembly 1 and outer sheath assembly 2 3, underground pipelines of different diameters can be protected, avoiding damage to the underground pipeline during the construction of the pit. At the same time, the underground pipeline is kept in a sealed and dry state, which improves the service life of the underground pipeline.

[0030] As a further embodiment of the present invention, the pulling mechanism includes a winding post 11. One end of the winding post 11 is rotatably connected to the inner wall of one side of the outer sheath assembly 1. A plurality of protrusions 18 are fixedly connected to the outer wall of the winding post 11. The outer walls of the plurality of protrusions 18 are slidably connected to the same turntable 12. By rotating the turntable 12, the winding post 11 is driven to rotate, thereby enabling the traction rope 9 to be wound around the outer wall of the winding post 11.

[0031] As a further embodiment of the present invention, a limiting plate 15 is fixedly connected to one side of the outer wall of each protrusion 18, and the other end of multiple protrusions 18 is fixedly connected to the same limiting disk 19 to prevent the turntable 12 from detaching from the winding column 11.

[0032] As a further embodiment of the present invention, a plurality of positioning plates 16 are fixedly connected to the top outer wall of the turntable 12, and a positioning post 10 is provided in the gap between two of the positioning plates 16. One end of the positioning post 10 is fixedly connected to the inner wall of one side of the outer sheath assembly 1. A plurality of connecting springs 17 are provided between the turntable 12 and the limiting plate 19. When the turntable 12 is in close contact with the limiting plate 15, one end of the positioning post 10 slightly exceeds the turntable 12. When it is necessary to rotate the turntable 12, force is applied to the turntable 12 to press it down. The retractable connecting spring 17 moves towards the limiting plate 19, allowing the positioning pin 10 to disengage from the gap between the two positioning plates 16. This enables the turntable 12 to rotate along with the winding 11. After rotation, the turntable 12 is released, and under the rebound force of the multiple connecting springs, the turntable 12 returns to its original position. The positioning pin 10 can then be inserted into the gap between the two positioning plates 16 to fix the turntable 12, preventing the winding pin 11 from rotating and causing the traction rope 9 to loosen and change the position of the placement plate 5.

[0033] Working principle: Multiple U-shaped bases 2 are placed in the foundation pit for installing the underground pipeline. Then, the outer sheath assembly 1 is fixed to the multiple U-shaped bases 2 with bolts. Next, by applying force to the turntable 12 in the pulling mechanism, it compresses the connecting spring 17 and moves it towards the limiting plate 19. This allows the positioning column 10 to disengage from the gap between two positioning plates 16, thereby allowing the turntable 12 to drive the winding 11 to rotate. The traction rope 9 is wound around the winding column 11, which pulls the slider 8 in the arc-shaped slide 7 upward along the arc-shaped slide 7. The connecting spring 14 on one side of the outer wall is stretched. When the slider 8 moves, the tilt angle of the placement plate 5 can be adjusted by the connecting plate 13 on its outer wall. After adjusting the multiple placement plates 5 to a suitable angle according to the diameter of the underground pipeline, the turntable 12 is released. Under the rebound force of the multiple connecting springs, the turntable 12 is reset, and the positioning column 10 can be inserted into the gap between two positioning plates 16 to fix the turntable 12 and prevent the winding column 11 from rotating and causing damage. The traction rope 9 is released to change the position of the placement plate 5. Then, the underground pipeline is placed in the outer sheath assembly 1, and the outer sheath assembly 2 is placed on top of the outer sheath assembly 1. The multiple arc-shaped blocks 22 on the bottom inner wall of the outer sheath assembly 2 are brought into contact with the outer wall of the underground pipeline. Under the rebound force of the multiple connecting springs 3 21, force is applied to the outer wall of the underground pipeline. Then, the flange fixing plate 1 6 and the flange fixing plate 2 20 are aligned and fixed together with multiple bolts. Through the cooperation of the multiple arc-shaped blocks 22 and the placement plate 5, the underground pipeline can be firmly fixed in the outer sheath assembly 1 and the outer sheath assembly 2 3. By setting the U-shaped base 2 and the protective cover 4, the soil pressure on the side wall and above of the underground pipeline pit can be supported and protected. Furthermore, by setting the outer sheath assembly 1 and the outer sheath assembly 2 3, underground pipelines of different diameters can be protected, avoiding damage to the underground pipeline during the construction of the pit. At the same time, the underground pipeline is kept in a sealed and dry state, which improves the service life of the underground pipeline. Example 2

[0034] Reference Figures 1-7 A support structure for a foundation pit spanning a large underground pipeline is provided. Compared with Embodiment 1, based on Embodiment 1, each U-shaped base 2 has an installation cavity 28 on both sides of its top end, and a telescopic plate 23 is slidably connected to the top of each installation cavity 28. The top end of the telescopic plate 23 is hinged to the bottom outer wall of the protective cover 4, and a lifting plate 27 is fixedly connected to the bottom end of the telescopic plate 23. When the top outer wall of the protective cover 4 is subjected to external force, it will press the telescopic plate 23 on the top of the U-shaped base 2, causing it to move downward, thereby retracting it into the installation cavity 28 inside the U-shaped base 2. At the same time, it will drive the lifting plate 27 to move downward along the inner wall of the installation cavity 28.

[0035] As a further embodiment of the present invention, a sliding groove 29 is provided on one side of the outer wall of the mounting cavity 28, and a pressing plate 30 and a pressing plate 31 are slidably connected to the upper and lower inner walls of the sliding groove 29, respectively. The bottom outer wall of the pressing plate 30 contacts the flange fixing plate 20, and the top outer wall of the pressing plate 31 contacts the flange fixing plate 6.

[0036] As a further embodiment of the present invention, racks 24 are fixedly connected to one outer wall of both pressing plate 30 and pressing plate 31, and racks 24 are slidably connected to the inner wall of the mounting cavity 28. A fixing post 25 is provided between the two racks 24, and the two ends of the fixing post 25 are rotatably connected to the inner wall of the mounting cavity 28. A gear 26 is fixedly connected to the outer wall of the middle part of the fixing post 25, and the gear 26 meshes with the racks 24 on both sides. The bottom outer wall of the lifting plate 27 contacts the rack 24 located above. During this process, the lifting plate 27 will apply force to the rack 24 located at the top, causing it to drive pressing plate 30 to move downward. Because the gear 26 meshes with the racks 24 on both sides, the rack 24 on the other side can move upward, causing pressing plate 31 below the inner wall of the sliding groove 29 to move upward. This allows force to be applied to the flange fixing plate 6 and flange fixing plate 20 between pressing plate 30 and pressing plate 31, making them fit more tightly and greatly improving the sealing effect.

[0037] Working principle: When the outer wall of the top of the protective cover 4 is subjected to external force, it will press the telescopic plate 23 on the top of the U-shaped base 2, causing it to move downward and retract into the mounting cavity 28 inside the U-shaped base 2. At the same time, it will drive the lifting plate 27 to move downward along the inner wall of the mounting cavity 28. During this process, the lifting plate 27 will exert force on the rack 24 located at the top, causing it to drive the pressing plate 30 to move downward. Because the gear 26 meshes with the racks 24 on both sides, it can cause the rack 24 on the other side to move upward, causing the pressing plate 31 below the inner wall of the sliding groove 29 to move upward. This can exert force on the flange fixing plate 6 and flange fixing plate 20 between the pressing plate 30 and the pressing plate 31, making them fit more tightly and greatly improving the sealing effect. Example 3

[0038] Reference Figures 1-8 A support structure for a foundation pit spanning a large underground pipeline, compared with Embodiment 2, has a sealing groove 32 on one side of the outer wall of the top of the flanged fixing plate 1 6, and a sealing block 33 is fixedly connected to one side of the outer wall of the bottom of the flanged fixing plate 20. The sealing block 33 and the sealing groove 32 are in the same vertical plane. The flanged fixing plate 1 6 and the flanged fixing plate 2 20 are fixed by bolts. When the outer sheath 1 1 and the outer sheath assembly 2 3 are combined together, the sealing block 33 at the bottom of the flanged fixing plate 2 20 will be embedded into the sealing groove 32 at the top of the flanged fixing plate 1 6.

[0039] As a further embodiment of the present invention, a plurality of connecting springs 35 are fixedly connected to the inner wall of the bottom of the sealing groove 32, and the same sealing gasket 34 is fixedly connected to the top of each of the connecting springs 35. The sealing block 33 applies force to the sealing gasket 34 in the sealing groove 32, causing it to press the connecting springs 35 downward. Under the action of the rebound force of the connecting springs 35, the sealing gasket 34 is pressed tightly against the bottom of the sealing block 33, thereby further and effectively improving the sealing effect between the outer sheath assembly 1 and the outer sheath assembly 2 3.

[0040] Working principle: When the outer sheath assembly 1 and outer sheath assembly 2 are assembled together by fixing the flange fixing plate 1 6 and flange fixing plate 2 20 with bolts, the sealing block 33 at the bottom of the flange fixing plate 2 20 will be embedded into the sealing groove 32 at the top of the flange fixing plate 1 6. The sealing block 33 will exert force on the sealing gasket 34 in the sealing groove 32, causing it to press the connecting spring 4 35 downward. Under the action of the rebound force of the connecting spring 4 35, the sealing gasket 34 will be tightly attached to the bottom end of the sealing block 33, thereby further and effectively improving the sealing effect between the outer sheath assembly 1 and outer sheath assembly 2 3.

[0041] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features, and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A support structure for a foundation pit spanning a large underground pipeline, comprising an outer sheath assembly one (1) and an outer sheath assembly two (3), characterized in that: The outer sleeve assembly one (1) has flanged fixing plates one (6) on both sides of its outer wall, and the outer sleeve assembly two (3) has flanged fixing plates two (20) on both sides of its outer wall. The outer sleeve assembly two (3) is connected to the flanged fixing plates one (6) by bolts. The bottom outer wall of the outer sleeve assembly one (1) is fixedly connected with multiple U-shaped bases (2) at equal intervals by bolts. Each U-shaped base (2) has a protective cover (4) at its top. The bottom inner wall of the outer sleeve assembly one (1) is provided with multiple pairs of arc-shaped grooves (7) at equal intervals. Each pair of arc-shaped grooves (7) is provided with a placement plate (5) between them. The inner wall of the arc-shaped slide (7) is slidably connected with a slider (8), and a connecting spring (14) is fixedly connected between the slider (8) and the inner wall of the arc-shaped slide (7). A connecting plate (13) is hinged between the slider (8) and the placement plate (5). A traction rope (9) is fixedly connected to the top outer wall of the slider (8), and a pulling mechanism is provided at the top of the traction rope (9). Multiple arc-shaped blocks (22) are evenly arranged on the bottom inner wall of the outer sheath assembly (3), and a connecting spring (21) is fixedly connected between the top outer wall of each arc-shaped block (22) and the top inner wall of the outer sheath assembly (3). The pulling mechanism includes a winding column (11), one end of which is rotatably connected to the inner wall of the outer sheath assembly (1), and a plurality of protrusions (18) are fixedly connected to the outer wall of the winding column (11), and the outer walls of the plurality of protrusions (18) are slidably connected to the same turntable (12). Each of the protrusions (18) has a limiting plate (15) fixedly connected to one side of its outer wall, and the other end of the multiple protrusions (18) is fixedly connected to the same limiting plate (19). Multiple positioning plates (16) are fixedly connected to the top outer wall of the turntable (12), and a positioning post (10) is provided in the gap between two of the positioning plates (16). One end of the positioning post (10) is fixedly connected to the inner wall of one side of the outer sheath assembly (1). Multiple connecting springs (17) are provided between the turntable (12) and the limiting plate (19). When the turntable (12) and the limiting plate (15) are in close contact, one end of the positioning post (10) slightly exceeds the turntable (12).

2. The support structure for a foundation pit spanning a large underground pipeline according to claim 1, characterized in that: Each of the U-shaped bases (2) has an installation cavity (28) on both sides of its top end, and a telescopic plate (23) is slidably connected to the top of the installation cavity (28). The top of the telescopic plate (23) is hinged to the bottom outer wall of the protective cover (4), and a lifting plate (27) is fixedly connected to the bottom of the telescopic plate (23).

3. The support structure for a foundation pit spanning a large underground pipeline according to claim 2, characterized in that: The mounting cavity (28) has a sliding groove (29) on one side of its outer wall, and the upper and lower inner walls of the sliding groove (29) are respectively connected to a pressing plate one (30) and a pressing plate two (31). The bottom outer wall of the pressing plate one (30) is in contact with the flange fixing plate two (20), and the top outer wall of the pressing plate two (31) is in contact with the flange fixing plate one (6).

4. The support structure for a foundation pit spanning a large underground pipeline according to claim 3, characterized in that: The outer walls of the first pressing plate (30) and the second pressing plate (31) are fixedly connected with racks (24), and the racks (24) are slidably connected to the inner wall of the mounting cavity (28). A fixing post (25) is provided between the two racks (24), and the two ends of the fixing post (25) are rotatably connected to the inner wall of the mounting cavity (28). A gear (26) is fixedly connected to the outer wall of the middle part of the fixing post (25), and the gear (26) meshes with the racks (24) on both sides. The bottom outer wall of the lifting plate (27) contacts the rack (24) located above.

5. The support structure for a foundation pit spanning a large underground pipeline according to claim 1, characterized in that: The outer wall of the top side of the flange fixing plate one (6) has a sealing groove (32), and the outer wall of the bottom side of the flange fixing plate two (20) has a sealing block (33) fixedly connected, and the sealing block (33) and the sealing groove (32) are in the same vertical plane.

6. The support structure for a foundation pit spanning a large underground pipeline according to claim 5, characterized in that: The bottom inner wall of the sealing groove (32) is fixedly connected with multiple connecting springs (35), and the top of each of the multiple connecting springs (35) is fixedly connected with the same sealing gasket (34).

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