Pipe jacking method based steel and concrete enclosure structure rapid small-diameter hole opening construction method

Abstract

The present application relates to the technical field of municipal engineering, and especially relates to a kind of steel-concrete enclosure structure quick small-diameter hole construction method based on pipe jacking method, which includes processing steel water tank, combined processing steel reinforcement cage and steel water tank, installing steel reinforcement cage, installing guide pipe, pouring pile body concrete, excavating hole after opening and constructing reinforcement ring beam and the like.The construction method of the present application optimizes pile foundation construction process, adopts the way of on-site combination pouring of steel water tank and steel reinforcement cage, greatly reduces the difficulty of opening hole and the time of chiseling pile, effectively prevents instability caused by disturbance of pile body, ensures the overall stability of enclosure structure, improves construction efficiency and safety, and effectively adapts to various municipal engineering small-diameter pipe jacking construction.

Description

Technical Field

[0001] This invention relates to the field of municipal engineering technology, and in particular to a method for rapidly opening small-diameter tunnels in steel-concrete retaining structures based on the pipe jacking method. Background Technology

[0002] When using pile foundations for the working shaft in pipe jacking construction, the opening at the pipe jacking location is typically created by first constructing the pile structure. After the piles reach a certain strength, the piles are partially chiseled to form the opening, and crossbeams are installed above and below the opening for reinforcement. Traditionally, after the piles have reached a certain strength, the working pit is excavated to the opening location, and then the piles are manually removed using pneumatic picks.

[0003] Traditional methods have significant drawbacks and are not suitable for small-diameter openings of 1.2m or less: Since pile structures are usually made of reinforced concrete, it is a very difficult project to partially remove the pile body after it has reached the required strength for excavation. This is not only due to the strength of the concrete, but also because the concrete of the pile body is wrapped with a dense layer of vertical reinforcing steel bars, which increases the lateral confinement and the difficulty of removal. In addition, there are certain dangers in removing the concrete of the pile body and cutting the reinforcing steel bars. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides a method for rapidly opening small-diameter tunnels in steel-concrete retaining structures based on the pipe jacking method.

[0005] The present invention provides a method for rapid construction of small-diameter openings in steel-concrete retaining structures based on pipe jacking, which adopts the following technical solution: S1. A steel water tank with a ring structure made of steel plate, with an inlet and an outlet welded to the top surface of the steel water tank, a central hole in the center of the steel water tank, and a ring-shaped inner cavity inside the steel water tank. S2. Use the steel water tank as the inner membrane of the reinforcing cage and weld it to the vertical bars and reinforcing bars of the reinforcing cage. S3. After the pile body drilling is completed and the hole is cleaned, the steel cage is installed. When the steel water tank is lowered to the pile hole, the inlet and outlet are opened to fill the steel water tank with water and then the inlet and outlet are closed. Then the steel cage is lowered. S4. Pass the conduit for pouring concrete through the central hole; S5. The pile body concrete is poured in a slow manner. During the concrete pouring process, the top elevation of the steel cage is monitored in real time and the concrete pouring speed is adjusted in time. The normal pouring speed can be resumed after the pile body concrete exceeds the top surface of the steel water tank. S6. After the concrete of the pile body reaches the required age, the soil is excavated to remove the scattered concrete, steel bars and steel water tank at the opening location. S7. The steel mesh of the reinforcing ring beam is welded using the top and bottom steel plates of the steel water tank, and then reinforced with concrete to form the reinforcing ring beam.

[0006] By adopting the above technical solutions, the construction method of the present invention optimizes the pile foundation construction process and adopts the method of on-site casting of steel water tank and steel cage, which greatly reduces the difficulty of opening the hole and the time of pile chiseling, effectively prevents instability caused by pile disturbance, ensures the overall stability of the retaining structure, improves construction efficiency and safety, and is effectively adapted to the small-diameter pipe jacking method construction of various municipal engineering projects.

[0007] Preferably, the number and size of the steel water tanks to be processed are determined according to the height and width of the opening at the location of the jacking pipe and the size of the pile diameter. If it is necessary to chisel half of the pile body, the steel water tanks should be installed as if one pile body is being excavated.

[0008] Preferably, both the water inlet and the vent are equipped with screw caps.

[0009] Preferably, when dismantling the reinforcing cage and steel water tank, the location of the opening is marked, and all the piles with the built-in steel water tank are marked to form the outline of the excavated opening. The actual size of the excavated opening is larger than the opening of the jacking pipe.

[0010] Preferably, after marking, the concrete outside the pile reinforcement cage is removed until part of the reinforcement cage and steel tank are exposed.

[0011] Preferably, a small opening is cut on the side of the steel tank to empty it.

[0012] Preferably, the steel reinforcement cage and the steel tank are cut.

[0013] Preferably, the concrete core column inside the central hole is removed using a pneumatic drill.

[0014] Preferably, the remaining reinforcing bars and the steel tank section are cut off. Attached Figure Description

[0015] Figure 1 This is a top view of the steel tank according to an embodiment of the present invention.

[0016] Figure 2 This is a front view of the steel tank according to an embodiment of the present invention.

[0017] Figure 3 This is a cross-sectional view of the steel water tank and the reinforcing cage in an embodiment of the present invention.

[0018] Figure 4 This is a front view of the steel water tank and the reinforcing cage in an embodiment of the present invention.

[0019] Figure 5 This is a top view of the steel water tank and the reinforcing cage in an embodiment of the present invention.

[0020] Figure 6 This is a schematic diagram of the location of the excavated hole in an embodiment of the present invention.

[0021] Figure 7 This is a schematic diagram of the reinforcing ring beam at the opening in an embodiment of the present invention.

[0022] Explanation of reference numerals in the attached drawings: 1. Steel water tank; 11. Water inlet; 12. Vent; 13. Center hole; 14. Inner cavity of the water tank; 2. Vertical reinforcement bar of the steel cage; 3. Reinforcing bar of the steel cage; 4. Outline of the excavation opening; 5. Reinforcing ring beam. Detailed Implementation

[0023] The following combination Figures 1-7 The present invention will be described in further detail below.

[0024] This invention discloses a method for rapidly opening small-diameter openings in steel-concrete retaining structures based on the pipe jacking method, including the following: S1. Processing the steel water tank 1, specifically including: determining the quantity and size of the steel water tank 1 to be processed according to the height and width of the opening at the location of the jacking pipe and the size of the pile diameter (usually the height of the steel water tank 1 includes the height of the reinforcing ring beam 5). If half of the pile body needs to be excavated, the steel water tank 1 should be installed as one pile body. The steel water tank 1 adopts a ring structure and serves as the inner membrane of the reinforcing cage. The water tank is made of steel plate with a thickness of not less than 6mm. A water inlet 11 and an exhaust port 12 are welded to the top surface of the steel water tank 1. Both are equipped with tightenable nuts. The water inlet 11 is used to connect to the external water source. The central part of the steel water tank 1 is a central hole 13 with a diameter of not less than 300mm to facilitate the smooth passage of the conduit for pouring concrete. The interior of the steel water tank 1 is a ring-shaped water tank cavity 14.

[0025] S2. Assemble the steel cage and the steel tank 1, specifically including: using the processed steel tank 1 as the inner membrane of the steel cage and welding it to the vertical bars 2 and the reinforcing bars 3 of the steel cage.

[0026] S3. Install the reinforcing cage, specifically including: after the pile body drilling is completed and the hole is cleaned, install the reinforcing cage. When the position of the steel water tank 1 is lowered to the pile hole, open the nuts on the inlet 11 and the vent 12, fill the steel water tank 1 with water, and then tighten the nuts on the inlet 11 and the vent 12. Then continue to lower the reinforcing cage.

[0027] S4. Install the conduit, specifically including: passing the conduit used for pouring concrete through the central hole 13. Since the steel tank 1 is used as the inner membrane during the processing of the steel cage, the processing accuracy of the steel cage must meet the requirement that the conduit can pass smoothly through the central hole 13 in the middle of the steel tank 1. During the installation of the conduit, ensure that the conduit is located in the center of the steel cage.

[0028] S5. Pouring pile concrete, specifically including: Due to the obstruction of the steel water tank 1, the resistance of mud and concrete returning during the pile concrete pouring process will increase, causing the problem of lifting the reinforcing cage. To solve this problem, after secondary hole cleaning and initial pouring, the pile concrete is poured at a slow speed so that the mud and concrete in the pile hole can return from the gap between the outside of the steel water tank 1 and the pile hole wall; During the concrete pouring process, the top elevation of the reinforcing cage is monitored in real time, and the concrete pouring speed is adjusted in time. After the pile concrete is poured above the top surface of the steel water tank 1, the normal pouring speed can be resumed; Since the number of piles with steel water tank 1 is limited (generally no more than 3), the slow concrete pouring method, with appropriate efficiency reduction, can ensure the smooth and convenient progress of subsequent construction.

[0029] S6. After excavation, the opening is chiseled, specifically including: after the pile concrete reaches the required strength, excavating the soil and removing the scattered concrete, rebar cage, and steel water tank 1 at the opening location; First, marking the opening location, marking all piles with internal steel water tank 1 to form the outline 4 of the opening to be chiseled. The actual size of the opening to be chiseled will be slightly larger than the opening of the jacking pipe; Second, after marking, chiseling away the concrete outside the pile rebar cage until part of the rebar cage and steel water tank 1 are exposed; Third, cutting a small opening on the side of steel water tank 1 with acetylene to empty steel water tank 1; Fourth, cutting the rebar cage and steel water tank 1; Fifth, using a pneumatic pick to chisel away the concrete core column inside the central hole 13; Sixth, cutting away the remaining rebar and part of steel water tank 1.

[0030] S7. Construction of the reinforcement ring beam 5, specifically including: using the top and bottom steel plates of the steel water tank 1 to weld the steel mesh of the reinforcement ring beam 5, pouring concrete to form the reinforcement ring beam 5, and simultaneously pouring concrete in the empty spaces of the pile body.

[0031] The construction method of this invention optimizes the pile foundation construction process by using a combination of steel water tank 1 and steel cage for on-site casting, which greatly reduces the difficulty of opening the hole and the time for pile chiseling, effectively prevents instability caused by pile disturbance, ensures the overall stability of the retaining structure, improves construction efficiency and safety, and is effectively adaptable to the small-diameter pipe jacking method construction of various municipal engineering projects.

[0032] The above are all preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for rapidly constructing small-diameter openings in steel-concrete retaining structures based on pipe jacking, characterized in that, Includes the following: S1. Make a ring-shaped steel water tank (1). Weld an inlet (11) and an exhaust port (12) to the top surface of the steel water tank (1). The center part of the steel water tank (1) is a central hole (13). The inside of the steel water tank (1) is a ring-shaped water tank cavity (14). S2. The steel water tank (1) is used as the inner membrane of the steel cage and welded to the vertical bars (2) and reinforcing bars (3) of the steel cage. S3. Install the steel cage. When the steel tank (1) is lowered to the pile hole, open the inlet (11) and the vent (12), fill the steel tank (1) with water, and then close the inlet (11) and the vent (12). Then continue to lower the steel cage. S4. Pass the conduit for pouring concrete through the central hole (13); S5. The concrete of the pile body is poured in a slow manner. During the concrete pouring process, the top elevation of the steel cage is monitored in real time and the concrete pouring speed is adjusted in time. The normal pouring speed can be restored after the concrete of the pile body exceeds the top surface of the steel water tank (1). S6. After the concrete strength of the pile body reaches the required age, the soil is excavated and the scattered concrete, steel bars and steel water tank (1) at the opening are removed. S7. Weld the steel mesh of the reinforcing ring beam (5) using the top and bottom steel plates of the steel water tank (1), and pour concrete to form the reinforcing ring beam (5). When the steel cage and steel water tank (1) are dismantled, the location of the opening is marked. All the piles with the steel water tank (1) inside are marked to form the outline of the opening (4). The actual size of the opening to be chiseled is larger than the opening of the jacking pipe. After marking, the concrete outside the steel cage of the pile body is chiseled away until part of the steel cage and steel water tank (1) are exposed. A small opening is cut on the side of the steel water tank (1) to empty the steel water tank (1).

2. The method for rapid small-diameter opening construction of steel-concrete retaining structures based on pipe jacking as described in claim 1, characterized in that: The number and size of the steel water tanks (1) to be processed are determined according to the height and width of the opening of the jacking pipe and the size of the pile diameter. If half of the pile body needs to be chiseled, the steel water tanks (1) should be installed according to one pile body.

3. The method for rapid small-diameter opening construction of steel-concrete retaining structures based on pipe jacking as described in claim 1, characterized in that: Both the inlet (11) and the vent (12) are equipped with screw caps.

4. The method for rapid small-diameter opening construction of steel-concrete retaining structures based on pipe jacking as described in claim 1, characterized in that: Cut the steel reinforcement cage and the steel water tank (1).

5. The method for rapid small-diameter opening construction of steel-concrete retaining structures based on pipe jacking as described in claim 4, characterized in that: The concrete core column inside the central hole (13) was removed using a pneumatic pick.

6. The method for rapid small-diameter opening construction of reinforced concrete retaining structures based on pipe jacking as described in claim 5, characterized in that: Cut the remaining steel bars and the steel tank (1) section.

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