Deep trench excavation and support method for heat network engineering construction

Abstract

The application discloses a deep trench excavation and supporting method for heat network engineering construction, and comprises the following steps: step one, installing a steel sheet pile; step two, pre-tensioning the steel sheet pile; step three, vertical excavation; step four, installing a surrounding purlin; step five, installing a support; and step six, fine processing of the trench bottom. The connecting strength of the wing plate and the rib plate is greatly improved through the connecting rod reinforcing structure of the steel sheet pile assembly, and the defect that the traditional steel sheet pile is prone to deformation is effectively avoided. Through the pre-tensioning design of the outer anchor rod and the steel wire rope, the pain points of the bending of the steel sheet pile and the cracking of the lock opening before the surrounding purlin is installed are solved, the inner space of the trench is not occupied, the subsequent operation is smooth, the hanging assembly is matched with the convex rib part through the plug sleeve, the surrounding purlin is borne through the hook, the traditional welding or bolt fixing is replaced, the surrounding purlin is quickly disassembled and assembled, the component reuse rate is improved, the construction cost is reduced, and the overall scheme considers safety, high efficiency and economy.

Description

Technical Field

[0001] This invention relates to the field of trench construction technology, specifically a method for deep trench excavation and support in heating network engineering construction. Background Technology

[0002] In the field of deep trench construction for heating network projects, the support system combining steel sheet piles with walers and supports has become the mainstream construction scheme due to its good soil retention and seepage prevention effect and strong adaptability. However, existing deep trench excavation and support methods still have the following drawbacks: 1. The connection between the waler and sheet piles is mostly achieved by welding or bolting, which is not only cumbersome and time-consuming to install, but also requires damage to the connection structure during dismantling, resulting in low component reuse rate and easy damage to the sheet pile body, seriously affecting construction efficiency; 2. After the sheet piles are inserted, excavation is required to the design elevation of the waler before the waler and support components can be installed. During this period, the sheet piles lack effective internal support and rely solely on their own rigidity to resist external soil pressure. They are prone to bending deformation due to unilateral overload, and may even lead to risks such as interlocking cracks and local instability. If support rods are installed directly between two opposite sheet piles to avoid premature deformation of the sheet piles, it will occupy the working space inside the trench and seriously interfere with subsequent excavation operations; 3. The strength of existing sheet piles mainly depends on the thickness of their own plates and structural design. The connection between the flange and the rib is a weak point. During excavation, tensile deformation is prone to occur due to concentrated soil pressure, further reducing the stability of the support system. Summary of the Invention

[0003] The purpose of this invention is to provide a method for deep trench excavation and support in heating network engineering construction, so as to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a method for deep trench excavation and support in heating network engineering construction, comprising the following steps: Step 1, installing steel sheet piles; Step 2, pre-tensioning the steel sheet piles; Step 3, vertical excavation; Step 4, installing walers; Step 5, installing support components; Step 6, fine treatment of the trench bottom; In step one above, the sheet pile assembly is inserted into the design edge of the trench to be excavated, so that the interlocking jaws of adjacent sheet pile assemblies interlock. In step two above, anchor rods are inserted on the outside of the sheet pile assembly, so that the steel wire ropes on the anchor rods tighten the sheet pile assembly. In step three above, vertical excavation is carried out along the inner side of the steel sheet pile assembly; In step four above, when the vertical excavation reaches the designed installation elevation of the waler, the excavation is stopped and the loose soil inside the sheet pile assembly is cleared. The suspension assembly is then installed on the sheet pile assembly, and the waler is installed on the suspension assembly. In step five above, support components are installed on the installed walers, and a hydraulic pre-jacking device is used to apply a preset support force to form a rigid internal support system. In step six above, vertical excavation continues along the inner side of the sheet pile assembly until it reaches 200-300mm above the designed trench bottom elevation, at which point manual cleaning is switched to the bottom.

[0005] In step one, the sheet pile assembly includes a rib plate, a raised rib, a wing plate, a groove, an interlocking part, a first connecting rod, a second connecting rod, and a third connecting rod. The rib plate is provided with two raised ribs, one end of which is fixedly connected to a wing plate. One end of the wing plate is provided with an interlocking part. A groove is provided on the wing plate, and a second connecting rod is fixedly connected in the groove. The two ends of the first connecting rod are respectively fixedly connected to the top ends of the two second connecting rods. A third connecting rod is fixedly connected to the second connecting rod, and the other end of the third connecting rod is fixedly connected to the first connecting rod.

[0006] In step one, the top of the inserted sheet pile assembly is 0.3-0.5m above the ground.

[0007] In step two, inserting anchor rods on the outside of the sheet pile assembly specifically involves inserting anchor rods longitudinally every 2-5 sheet pile assemblies at a distance of 1.5-2m from the outside of the sheet pile assembly, with the anchor rods penetrating the soil to a depth of 1.5m.

[0008] In step two, the anchor rod protrudes 0.2-0.3m above the ground and the steel wire rope is fixed. The other end of the steel wire rope is fixed to the first connecting rod, and a pre-tightening force of 30-50kN is applied to the steel wire rope.

[0009] In step three, the vertical excavation adopts a layered excavation method, with each layer excavating to a depth of 1.5m. The excavated soil is transported by an excavator to an area 2m away from the outside of the trench and piled up to a height of 1.5m.

[0010] In step four, the suspension assembly includes a mounting plate, a sleeve, a connecting frame, a hook, and a stiffener. The connecting frame is fixedly connected to the lower surface of the mounting plate. Sleeves are provided on both sides of the connecting frame and are fixedly connected to the mounting plate. Hooks are fixedly connected to the connecting frame, and stiffeners are fixedly connected to the hooks.

[0011] In step four, the installation of the suspension assembly on the sheet pile assembly specifically involves inserting the connecting frame from top to bottom between the two protruding ribs, so that the insert sleeve is inserted into the rib groove of the protruding rib, until the mounting plate is blocked by the rib plate.

[0012] In step four, the waler is installed on the hook of the suspension assembly.

[0013] In step six, during the manual cleaning process, drainage ditches are dug on both sides of the bottom of the tank, and a water collection pit is set up every 30-50m. Submersible pumps are used to continuously pump out the accumulated water to ensure that the bottom of the tank is dry.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention significantly improves the connection strength between the wing plate and the rib plate through the connecting rod reinforcement structure of the steel sheet pile assembly, effectively avoiding the defects of traditional steel sheet piles that are prone to tensile deformation; Through the pre-tensioning design of the outer anchor rod and wire rope, the pain points of steel sheet pile bending and interlocking cracking before waler installation are solved, and the inner space of the trench is not occupied, ensuring smooth subsequent operations; The suspension assembly uses the sleeve and the protruding rib to cooperate and the hook to support the waler, replacing the traditional welding or bolt fixing, realizing the rapid disassembly and assembly of the waler, improving the component reuse rate, reducing construction costs, and the overall solution takes into account safety, efficiency and economy. Attached Figure Description

[0015] Figure 1 This is a flowchart of the method of the present invention; Figure 2 This is a schematic diagram of the vertical excavation operation of the present invention; Figure 3 This is a three-dimensional structural diagram of the steel sheet pile assembly of the present invention in its spliced ​​state. Figure 4 This is a three-dimensional structural diagram of the steel sheet pile assembly of the present invention; Figure 5 This is a three-dimensional structural diagram of the suspension assembly of the present invention.

[0016] In the diagram: 1. Sheet pile assembly; 11. Rib plate; 12. Raised rib; 13. Wing plate; 14. Groove; 15. Interlocking part; 16. First connecting rod; 17. Second connecting rod; 18. Third connecting rod; 2. Suspension assembly; 21. Mounting plate; 22. Sleeve; 23. Connecting frame; 24. Hook; 25. Rib plate; 3. Waler; 4. Support component; 5. Wire rope; 6. Anchor bolt. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] Please see the appendix Figure 1 -Appendix Figure 5 The present invention provides an embodiment of a deep trench excavation and support method for heating network engineering construction, comprising the following steps: Step 1, installing steel sheet piles; Step 2, pre-tensioning the steel sheet piles; Step 3, vertical excavation; Step 4, installing walers; Step 5, installing support components; Step 6, fine treatment of the trench bottom. In step one above, the sheet pile assembly 1 is inserted into the design edge of the trench to be excavated, so that the interlocking jaws of adjacent sheet pile assemblies 1 interlock with each other, and the top of the inserted sheet pile assembly 1 is 0.3-0.5m above the ground. The sheet pile assembly 1 includes a rib plate 11, a rib portion 12, a wing plate 13, a groove 14, an interlocking portion 15, a first connecting rod 16, a second connecting rod 17, and a third connecting rod 18. The rib plate 11 is provided with two rib portions 12, one end of which is fixedly connected to the wing plate 13. One end of the wing plate 13 is provided with the interlocking portion 15. The wing plate 13 is provided with a groove 14, and the second connecting rod 17 is fixedly connected in the groove 14. The two ends of the first connecting rod 16 are respectively fixedly connected to the top ends of the two second connecting rods 17. The third connecting rod 18 is fixedly connected to the second connecting rod 17, and the other end of the third connecting rod 18 is fixedly connected to the first connecting rod 16. In step two above, anchor rods 6 are inserted longitudinally every 2-5 sheet pile assemblies 1, 1.5-2m outside the sheet pile assembly 1. The anchor rods 6 are inserted into the soil to a depth of 1.5m and protrude 0.2-0.3m above the ground. The anchor rods 6 are fixed with wire ropes 5, and the other end of the wire ropes 5 is fixed to the first connecting rod 16. The wire ropes 5 are subjected to a pre-tightening force of 30-50kN, so that the wire ropes 5 on the anchor rods 6 tighten the sheet pile assembly 1. In step three above, vertical excavation is carried out along the inner side of the steel sheet pile assembly 1. The vertical excavation adopts a layered excavation method, with each layer having an excavation depth of 1.5m. The excavated soil is transported by an excavator to an area 2m away from the outside of the trench and piled up to a height of 1.5m. In step four above, when the vertical excavation reaches the designed installation elevation of the waler 3, the excavation is stopped and the loose soil inside the sheet pile assembly 1 is cleared. The suspension assembly 2 is installed on the sheet pile assembly 1, and the connecting frame 23 is inserted from top to bottom between the two protruding ribs 12, so that the insert 22 is inserted into the rib groove of the protruding rib 12 until the mounting plate 21 is blocked by the rib plate 11. Then, the waler 3 is installed on the hook 24 of the suspension assembly 2. The suspension assembly 2 includes a mounting plate 21, insert 22, connecting frame 23, hook 24 and rib plate 25. The connecting frame 23 is fixedly connected to the lower surface of the mounting plate 21. Insert 22 is provided on both sides of the connecting frame 23 and the insert 22 is fixedly connected to the mounting plate 21. The hook 24 is fixedly connected to the connecting frame 23, and the rib plate 25 is fixedly connected to the hook 24. In step five above, support members 4 are installed on the installed waler 3, and a preset support force is applied by a hydraulic pre-jacking device to form a rigid internal support system. In step six above, vertical excavation continues along the inner side of the sheet pile assembly 1 until it reaches 200-300mm above the designed trench bottom elevation. Then, manual cleaning is switched to the bottom. During the manual cleaning process, drainage ditches are dug on both sides of the trench bottom, and a water collection pit is set every 30-50m. Submersible pumps are used to continuously pump out the accumulated water to ensure that the trench bottom is dry.

[0019] Based on the above, the advantages of the present invention are as follows: In the sheet pile assembly 1 of the present invention, the rib plate 11 and the wing plate 13 constitute the main body, the protruding rib portion 12 is used to improve the strength of the rib plate 11 and is also used to install the suspension assembly 2, the groove 14 is used to accommodate the second connecting rod 17, the interlocking portion 15 is used to realize the interlocking engagement between adjacent sheet pile assemblies 1, the first connecting rod 16, the second connecting rod 17 and the third connecting rod 18 constitute a reinforcing structure to prevent excessive stress at the connection between the wing plate 13 and the rib plate 11, and the third connecting rod 18 is used to improve the connection strength between the first connecting rod 16 and the second connecting rod 17; in the suspension assembly 2, the insert 22 cooperates with the protruding rib portion The rib groove of 12 is used to lock the mounting plate 21, the connecting frame 23 is used to support the hook 24, the hook 24 is used to install the waler 3, and the rib plate 25 is used to improve the strength of the hook 24. The suspension component 2 replaces welding or bolt fixing, which is convenient and efficient to disassemble and assemble. It not only reduces the labor intensity of construction and shortens the operation time, but also avoids damage to the components and improves the reuse rate of the components. The anchor rod 6 is pre-tensioned to the first connecting rod 16 by the wire rope 5, which can prevent the steel sheet pile component 1 from bending and deforming due to the lack of internal support during vertical excavation. In addition, since it does not occupy the working space inside the trench, it avoids interference with the excavation operation.

[0020] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A method for deep trench excavation and support in heating network engineering construction, comprising the following steps: Step 1: Install sheet piles; Step 2: Pre-tighten sheet piles; Step 3: Vertical excavation; Step 4: Install walers; Step 5: Install supports; Step 6: Fine treatment of trench bottom; Its features are: In step one above, the sheet pile assembly (1) is inserted into the design edge of the trench to be excavated, so that the interlocking mouths of adjacent sheet pile assemblies (1) interlock with each other. In step two above, an anchor rod (6) is inserted on the outside of the sheet pile assembly (1) so that the wire rope (5) on the anchor rod (6) tightens the sheet pile assembly (1). In step three above, vertical excavation is carried out along the inner side of the sheet pile assembly (1); In step four above, when the vertical excavation reaches the designed installation elevation of the waler (3), the excavation is stopped and the loose soil inside the sheet pile assembly (1) is cleared. The suspension assembly (2) is installed on the sheet pile assembly (1), and the waler (3) is installed on the suspension assembly (2). In step five above, support members (4) are installed on the installed waler (3), and a preset support force is applied by a hydraulic pre-jacking device to form a rigid internal support system; In step six above, vertical excavation continues along the inner side of the sheet pile assembly (1) until it reaches 200-300mm above the designed trench bottom elevation, at which point manual cleaning is switched.

2. The method for deep trench excavation and support in heating network engineering construction according to claim 1, characterized in that: In step one, the sheet pile assembly (1) includes a rib (11), a rib (12), a wing (13), a groove (14), an interlock (15), a first connecting rod (16), a second connecting rod (17), and a third connecting rod (18). The rib (11) is provided with two ribs (12). One end of the rib (12) is fixedly connected to the wing (13). One end of the wing (13) is provided with an interlock (15). The wing (13) is provided with a groove (14). The second connecting rod (17) is fixedly connected in the groove (14). The two ends of the first connecting rod (16) are respectively fixedly connected to the top ends of the two second connecting rods (17). The third connecting rod (18) is fixedly connected to the second connecting rod (17), and the other end of the third connecting rod (18) is fixedly connected to the first connecting rod (16).

3. The method for deep trench excavation and support for heating network engineering construction according to claim 1, characterized in that: In step one, the top of the inserted sheet pile assembly (1) is 0.3-0.5m above the ground.

4. The method for deep trench excavation and support in heating network engineering construction according to claim 1, characterized in that: In step two, inserting anchor rods (6) on the outside of the sheet pile assembly (1) specifically means: inserting anchor rods (6) longitudinally every 2-5 sheet pile assemblies (1) at a distance of 1.5-2m on the outside of the sheet pile assembly (1), with the anchor rods (6) penetrating to a depth of 1.5m.

5. A method for deep trench excavation and support in heating network engineering construction according to claim 1, characterized in that: In step two, the anchor rod (6) protrudes 0.2-0.3m above the ground and the wire rope (5) is fixed. The other end of the wire rope (5) is fixed on the first connecting rod (16), and the wire rope (5) is subjected to a pre-tightening force of 30-50kN.

6. The method for deep trench excavation and support in heating network engineering construction according to claim 1, characterized in that: In step three, the vertical excavation adopts a layered excavation method, with each layer excavating to a depth of 1.5m. The excavated soil is transported by an excavator to an area 2m away from the outside of the trench and piled up to a height of 1.5m.

7. A method for deep trench excavation and support in heating network engineering construction according to claim 1, characterized in that: In step four, the suspension assembly (2) includes a mounting plate (21), a sleeve (22), a connecting frame (23), a hook (24), and a stiffener (25). The lower surface of the mounting plate (21) is fixedly connected to the connecting frame (23). Sleeves (22) are provided on both sides of the connecting frame (23), and the sleeves (22) are fixedly connected to the mounting plate (21). Hooks (24) are fixedly connected to the connecting frame (23), and stiffeners (25) are fixedly connected to the hooks (24).

8. A method for deep trench excavation and support for heating network engineering construction according to claim 1, characterized in that: In step four, installing the suspension assembly (2) on the sheet pile assembly (1) specifically involves inserting the connecting frame (23) from top to bottom between the two protruding ribs (12), so that the insert (22) is inserted into the rib groove of the protruding rib (12) until the mounting plate (21) is blocked by the rib plate (11).

9. A method for deep trench excavation and support in heating network engineering construction according to claim 1, characterized in that: In step four, the waler (3) is installed on the hook (24) of the suspension assembly (2).

10. A method for deep trench excavation and support in heating network engineering construction according to claim 1, characterized in that: In step six, during the manual cleaning process, drainage ditches are dug on both sides of the bottom of the tank, and a water collection pit is set up every 30-50m. Submersible pumps are used to continuously pump out the accumulated water to ensure that the bottom of the tank is dry.

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