In-situ repair method for deformation of steel pipe jacking

Abstract

The application discloses a kind of in-situ repair method of steel pipe deformation, comprising the following steps: step S1: measuring the deformation area on steel pipe;Step S2: support is set above the deformation area, and the deformation area is unloaded by earth excavation, and the pipe shed grouting reinforcement and waterproof treatment are carried out on the periphery of the deformation area;Step S3: the area reinforced by pipe shed grouting is used as template, grouting reinforcement is carried out in the support area above the deformation area, and the arch support structure is formed after grouting reinforcement above the deformation area;Step S4: support assembly is arranged at both ends of the deformation area to support steel pipe, the deformation area is cut, the two sections of steel pipe after cutting are contacted and connected to form an integrated body by continuing pipe construction, and then the pipe construction is continued.The in-situ repair method solves the technical problem of construction safety hazard in the repair of steel pipe deformation in the water-rich sand layer in the prior art.

Description

Technical Field

[0001] This invention belongs to the field of pipe jacking construction technology, specifically relating to an in-situ repair method for deformation of steel pipe jacking. Background Technology

[0002] Pipe jacking is a trenchless construction technique that primarily uses two types of pipes: concrete pipes and steel pipes. For complex geological conditions and special areas, steel-casing pipe jacking technology is also employed, combining steel and concrete pipes to ensure the safety of construction and the surrounding environment. During actual construction, factors such as deep burial depth and overloading can easily cause deformation of the outer large-diameter steel pipe, affecting the normal construction of the inner concrete pipe.

[0003] Chinese invention patent application number 202310857234.7 discloses a method for trenchless repair of pipeline deformation during steel pipe jacking construction, including the following steps: measuring and marking the end positions of the pipeline deformation area during steel pipe jacking construction; modifying the normal steel pipe on the side of the deformation area away from the jacking head; reinforcing the end of the deformation area on the side closer to the jacking head; pre-reinforcing and waterproofing the soil in the deformation area; combining segmented cutting of the deformation area with pipeline jacking construction; and connecting the front and rear ends after the deformation area is cut off. This construction method uses one or more of the following methods—grouting, high-pressure jet mixing, and freezing—for pre-reinforcing and waterproofing the soil in the deformation area. Specifically, the construction combines external ground-to-ground construction with grouting holes inside the pipe. When the area where the steel pipe is located is a water-rich sand layer, using grouting holes inside the pipe poses a risk of water ingress into the steel pipe, affecting construction safety. Summary of the Invention

[0004] In view of the existing technical problems, the present invention aims to provide an in-situ repair method for steel jacking pipe deformation, which can solve the technical problem of construction safety hazards in the repair of steel jacking pipe deformation located in water-rich sand layer in the prior art.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] An in-situ repair method for deformed steel jacking pipes includes the following steps:

[0007] Step S1: Measure the deformation area on the steel jacking pipe;

[0008] Step S2: Set up support above the deformation area, excavate and unload the soil above the deformation area, and reinforce and waterproof the pipe perimeter of the deformation area with pipe roof grouting.

[0009] Step S3: Using the area reinforced by pipe roof grouting as a template, grouting reinforcement is carried out in the support area above the deformation area, so that an arched support structure is formed after grouting reinforcement above the deformation area.

[0010] Step S4: Set up support components at both ends of the deformation area to support the steel jacking pipe, cut the deformation area, and continue the jacking construction so that the two cut steel jacking pipe sections come into contact and connect to form a whole, and then continue the jacking construction.

[0011] The pipe roof grouting in step S2 is a conventional support method in existing technology. Pipe roof grouting, also known as the pipe roof method, is a pre-support technology used in tunnel and underground engineering construction for advanced support and reinforcement of weak and fractured surrounding rock. A specific construction method is also given in a three-dimensional reinforcement construction method suitable for the expansion of collapsed tunnels disclosed in Chinese Invention Patent Application No. 201910595135X. Pipe roof grouting forms a waterproof layer, and the reinforced area formed after pipe roof grouting is used as a template for top grouting reinforcement, further sealing the upper part of the steel jacking pipe and bearing the load of the upper part of the steel jacking pipe, ensuring the safety of operations inside the steel jacking pipe. The in-situ repair method for deformed steel jacking pipes in this application involves supporting the area above the deformed zone, followed by top unloading, grouting reinforcement around the steel jacking pipe (corresponding to step S2), grouting reinforcement at the top of the steel jacking pipe (corresponding to step S3), and internal support components. This ensures that the reinforced soil around the steel jacking pipe meets the requirements for bearing capacity and waterproofing, and forms an arched support structure on top of the steel jacking pipe, ensuring the safety of cutting, connecting, and jacking construction in the deformed area. Compared with existing excavation repair technologies, the in-situ repair method for deformed steel jacking pipes of this invention is safe and reliable, requires less earthwork excavation, and has lower project costs, resulting in significant economic, social, and environmental benefits.

[0012] Preferably, in step S2, sheet pile support is installed above the deformation area, and the top of the area surrounded by the sheet pile support is excavated and unloaded in layers. The pile length during sheet pile construction is based on the design calculation results of the actual project. The purpose of excavating and unloading the top of the steel jacking pipe is to reduce the load on the top of the steel jacking pipe, ensure construction safety during in-situ repair of large-diameter steel jacking pipes, and ensure that the steel jacking pipe will not deform again after repair.

[0013] Preferably, in step S2, the lateral position of the steel sheet pile support is located on the left and right sides of the deformation area with a length L1, using the central axis of the steel jacking pipe as the reference line, where L1≥r+2m, and r is the radius of the steel jacking pipe in meters; the longitudinal position of the steel sheet pile support is located on the front and rear sides with a length L2, using the deformation area of ​​the steel jacking pipe as the reference, where L2≥2m.

[0014] Preferably, in step S2, a double-row pipe roof is arranged around the pipe in the deformation area for grouting reinforcement to form a circular support structure, using cement and water glass dual-liquid grouting. The axial centerline of the circular support structure is collinear with the axial centerline of the steel jacking pipe, and the grouting coverage of the inner pipe roof grouting pipe partially overlaps with that of the outer pipe roof grouting pipe. This in-situ repair method integrates waterproofing into the reinforcement process, utilizing the advantages of cement + water glass dual-liquid grouting, namely rapid solidification and waterproofing characteristics, to effectively block groundwater infiltration and ensure operational safety during steel jacking pipe cutting. Simultaneously, setting up two rows of pipe roof grouting further ensures that a complete waterproof layer is formed after pipe roof grouting reinforcement, preventing groundwater infiltration.

[0015] Preferably, the thickness of the annular support structure is not less than 1.2m, and the length of the annular support structure is L3, where L3 ≥ L + 1m, and L is the length of the deformation area in meters.

[0016] Preferably, in step S3, the arched support structure includes an arc-shaped structure and first support structures located on the left and right sides of the arc-shaped structure. The axial centerline of the arc-shaped structure is collinear with the axial centerline of the steel jacking pipe. To form the arched support structure, the length of the top grouting pipe and the grouting volume need to be set and controlled to ensure that the arched support structure is formed after grouting. The cement material used for grouting has excellent load-bearing properties. Using an arched support structure can fully utilize the material's mechanical properties, ensuring construction safety and good economic benefits.

[0017] Preferably, the arc-shaped structure is a semi-circular structure, both first support structures are horizontal structures, and the axial centerline of the steel jacking pipe is located on the plane where the two first support structures are located.

[0018] Preferably, in step S4, the support assembly includes a first component that fits against the inner wall of the steel jacking pipe, a second component disposed at the center of the first component, and support rods connecting the first and second components. Multiple support rods are arranged circumferentially around the axial centerline of the steel jacking pipe. The first component has a circular cross-sectional shape, the diameter of which matches the inner diameter of the steel jacking pipe. The second component has a circular or rectangular cross-sectional shape, and the axial centerline of the steel jacking pipe passes through the center of the second component. Supporting the steel jacking pipe with the support assembly further ensures construction safety.

[0019] Preferably, at least three support components are provided at both ends of the deformation area on the steel jacking pipe, with adjacent support components spaced apart.

[0020] Preferably, the method also includes step S5: continue the pipe jacking construction until completion, remove the support components inside the steel pipe, install a concrete pipe inside the steel pipe, fill the gap between the steel pipe and the concrete pipe with grout, and after the grout reaches the design strength, remove the grouting pipe and support structure above the steel pipe, and restore the unloading area above the deformation area to the height before unloading.

[0021] Compared with existing technologies, the beneficial effects of this invention are as follows: The in-situ repair method for deformed steel jacking pipes of this invention involves supporting the area above the deformed zone, followed by top unloading, grouting reinforcement around the steel jacking pipe, grouting reinforcement at the top of the steel jacking pipe, and internal support components. This ensures that the reinforced soil around the steel jacking pipe meets the requirements for bearing capacity and waterproofing, and forms an arched support structure on top of the steel jacking pipe, ensuring the safety of cutting, connecting, and jacking construction in the deformed area. Compared with existing excavation repair technologies, the in-situ repair method for deformed steel jacking pipes of this invention is safe and reliable, requires less earthwork excavation, and has lower project costs, resulting in significant economic, social, and environmental benefits. Attached Figure Description

[0022] Figure 1 This is a top view of a jacking project in one embodiment of the in-situ repair method for deformation of steel jacking pipe according to the present invention;

[0023] Figure 2 for Figure 1 Cross-sectional view of the deformed jacking pipe of China Steel Group.

[0024] Figure 3 for Figure 1 Cross-sectional view of sheet pile support installed in the AA direction;

[0025] Figure 4 for Figure 3 Cross-sectional view after unloading;

[0026] Figure 5 for Figure 1 Cross-sectional view of the pipe roof grouting process around the pipe jacking pipe of China Steel Group;

[0027] Figure 6 for Figure 1 AA-direction cross-section diagram during grouting reinforcement;

[0028] Figure 7 for Figure 1 BB-direction cross-section diagram when setting support components;

[0029] Figure 8 for Figure 7 A schematic diagram of the structure of the central support component;

[0030] Figure 9 for Figure 1 Schematic diagram of the BB-direction structure when connecting the jacking pipes of China Steel Group.

[0031] Figure 10 for Figure 1 Schematic diagram of the BB-direction structure after the repair of the pipe jacking project by China Steel.

[0032] In the diagram:

[0033] 1-Steel jacking pipe; 101-Deformation zone; 2-Concrete pipe; 3-Working shaft; 4-Receiving shaft; 5-Steel sheet pile support; 6-Arch-shaped support structure; 601-Circular arc structure; 602-First support structure; 7-Support component; 701-First component; 702-Second component; 703-Support rod; 8-Circular ring support structure; 9-Excavation area; 10-Pipe roof grouting pipe; 1001-First pipe roof grouting pipe; 1002-Second pipe roof grouting pipe; 11-First grouting pipe; 12-Grouting material; 13-Weld; 14-Plain fill. Detailed Implementation

[0034] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other. For ease of description, the terms "upper," "lower," "left," and "right" used below only indicate that they correspond to the upper, lower, left, and right directions in the accompanying drawings and do not limit the structure.

[0035] like Figure 1 and Figure 2 As shown, in this embodiment, the diameter of the steel jacking pipe 1 is 2m, and the diameter of the concrete pipe 2 to be installed inside the steel jacking pipe 1 is 1.5m. Working wells 3 and receiving wells 4 are respectively opened from the ground at both ends of the steel jacking pipe 1. Figure 3 As shown, the soil layers where the steel jacking pipe 1 is located, from bottom to top, consist of completely weathered silty mudstone, medium-coarse sand, silty clay, and plain fill. The steel jacking pipe 1 is situated within the medium-coarse sand, and a deformation area 101 exists on the surface of the steel jacking pipe 1. This embodiment provides an in-situ repair method for the deformation of a steel jacking pipe, specifically including the following steps:

[0036] Step S1: Accurately measure the deformation area 101 on the steel jacking pipe 1 using instruments;

[0037] Step S2: As Figure 3 and Figure 6As shown, to provide support during the excavation and unloading of the top of the steel jacking pipe 1, sheet pile supports 5 are installed above the deformation zone 101. The axial centerline of the steel jacking pipe 1 is used as the baseline, and the sheet pile supports 5 are positioned laterally to the left and right of the baseline by extending 3.5m (radius of the steel jacking pipe 1 plus 2.5m). The deformation zone 101 is used as the reference, and the sheet pile supports 5 are positioned longitudinally by extending 2.5m forward and backward to both sides of this reference. During the construction of the sheet pile supports, the pile length is based on the design calculations of the actual project. Figure 3 and Figure 4 As shown, the top of the deformation zone 101 is the excavation zone 9. Excavation and unloading are carried out in excavation zone 9 twice, with each excavation reaching a depth of 1m. Figure 5 and Figure 6 As shown, the pipe roof grouting reinforcement and waterproofing treatment are carried out around the pipe in the deformation area 101. Double rows of pipe roof grouting pipes 10 are arranged outside the deformation area 101 of the steel jacking pipe 1 to form a circular support structure 8. Cement + water glass double liquid grouting is adopted. The pipe roof grouting design coverage range is 1.6m in radial width and 0.5m in single pipe roof grouting radius. Among them, the distance between the first pipe roof grouting pipe 1001 located on the inner side and the steel jacking pipe 1 is 0.6m. The row spacing between the second pipe roof grouting pipe 1002 located on the outer side and the first pipe roof grouting pipe 1001 is 0.6m. The axial center line of the circular support structure 8 is collinear with the axial center line of the steel jacking pipe 1. The thickness of the circular support structure 8 is 1.6m. The length of the circular support structure 8 is based on the deformation area 101 and 1m is added to the front and rear sides of the base.

[0038] Step S3: As Figure 6 As shown, the area reinforced by pipe roof grouting is used as a template. A first grouting pipe 11 is installed in the support area above the deformation area 101 for grouting reinforcement, so that an arched support structure 6 is formed after grouting reinforcement above the deformation area 101. The arched support structure 6 includes an arc-shaped structure 601 and first support structures 602 located on the left and right sides of the arc-shaped structure 601. The axial center line of the arc-shaped structure 601 is collinear with the axial center line of the steel jacking pipe 1. The arc-shaped structure 601 is a semi-circular structure. Both first support structures 602 are horizontal structures, and the axial center line of the steel jacking pipe 1 is located on the plane where the two first support structures 602 are located. The length of the arched support 6 is 1m forward and backward from the deformation area 101 plus 1m on each side. The thickness of the arched support 6 is 100mm. The width of the first support structure 602 is 1m.

[0039] Step S4: As Figure 7 As shown, support components 7 are installed at both ends of the deformation zone 101 to support the steel jacking pipe 1; as Figure 8As shown, the support assembly 7 includes a first component 701 that fits against the inner wall of the steel jacking pipe 1, a second component 702 disposed at the center of the first component 701, and support rods 703 connecting the first component 701 and the second component 702. Twelve support rods 703 are arranged circumferentially around the axial centerline of the steel jacking pipe 1. The first component 701 has a circular cross-section, and its diameter is determined according to the diameter and wall thickness of the steel jacking pipe 1, allowing it to be smoothly placed inside the steel jacking pipe 1 and providing good support, thus ensuring the safety of workers operating inside the steel jacking pipe 1. The second component 702 has a rectangular cross-section, and the axial centerline of the steel jacking pipe 1 passes through the center of the second component 702. Three support assemblies 7 are disposed at both ends of the deformation area 101 on the steel jacking pipe 1, with adjacent support assemblies 7 spaced 0.5m apart. Figure 9 As shown, the deformed area 101 is cut, and the pipe jacking construction continues until the two cut sections of steel pipe 1 come into contact and are welded together to form a single unit. Figure 9 The dotted line in the diagram represents weld 13, and then the pipe jacking construction continues;

[0040] Step S5: Continue pipe jacking construction until completion, such as... Figure 10 As shown, the supporting components 7 inside the steel jacking pipe 1 are removed, and a concrete pipe 2 is installed inside the steel jacking pipe 1. The gap between the steel jacking pipe 1 and the concrete pipe 2 is filled with grout 12. After the grout 12 reaches the design strength, the grouting pipe and support structure above the steel jacking pipe 1 are removed, and the unloading area above the deformation area 101 is backfilled with plain fill soil 14 to the top surface elevation.

[0041] The in-situ repair method for steel jacking pipe deformation in this embodiment adopts steel sheet pile support for excavation and unloading of soil at the top of the steel jacking pipe, grouting reinforcement around the steel jacking pipe, grouting reinforcement at the top of the steel jacking pipe, and internal support components for the steel jacking pipe. This method ensures that the reinforced soil around the steel jacking pipe meets the requirements for bearing capacity and waterproofing, and forms an arched support structure on the upper part of the steel jacking pipe to ensure the safety of cutting, welding, and jacking construction in the deformed area of ​​the steel jacking pipe.

[0042] The above embodiments should be understood as being used only to illustrate the present invention more clearly, and not to limit the scope of the present invention. After reading the present invention, any modifications of the present embodiments by those skilled in the art will fall within the scope defined by the appended claims.

Claims

1. A method for in-situ repair of deformation of steel jacking pipe, characterized in that: Includes the following steps: Step S1: Measure the deformation area (101) on the steel jacking pipe (1); Step S2: Set up a support above the deformation area (101), and excavate and unload the soil above the deformation area (101). Perform pipe roof grouting reinforcement and waterproofing treatment around the pipe in the deformation area (101). Set up sheet pile support (5) above the deformation area (101), and excavate and unload the soil at the top of the area surrounded by the sheet pile support (5). Excavate in layers. Step S3: Using the area reinforced by pipe roof grouting as a template, grouting reinforcement is carried out in the support area above the deformation area (101), so that an arch support structure (6) is formed after grouting reinforcement above the deformation area (101); the arch support structure (6) includes an arc-shaped structure (601) and a first support structure (602) located on the left and right sides of the arc-shaped structure (601), the axial center line of the arc-shaped structure (601) is collinear with the axial center line of the steel jacking pipe (1); Step S4: Set up support components (7) at both ends of the deformation area (101) to support the steel jacking pipe (1), cut the deformation area (101), continue the jacking construction so that the two sections of steel jacking pipe (1) after cutting come into contact and connect to form a whole, and then continue the jacking construction.

2. The in-situ repair method for deformation of steel jacking pipe according to claim 1, characterized in that: In step S2, the horizontal position of the sheet pile support (5) is located on the left and right sides of the deformation area (101) with length L1, with L1≥r+2m, where r is the radius of the sheet pile (1) in meters; the longitudinal position of the sheet pile support (5) is located on the front and rear sides with length L2, with L2≥2m, with the deformation area of ​​the sheet pile (1) as the reference.

3. The in-situ repair method for deformation of steel jacking pipe according to claim 1, characterized in that: In step S2, double rows of pipe sheds are arranged around the pipe in the deformation area (101) for grouting reinforcement to form a circular support structure (8), using cement and water glass double liquid grouting; the axial center line of the circular support structure (8) is collinear with the axial center line of the steel jacking pipe (1), and the grouting coverage of the pipe shed grouting pipe located on the inner side partially overlaps with the grouting coverage of the pipe shed grouting pipe located on the outer side.

4. The in-situ repair method for deformation of steel jacking pipe according to claim 3, characterized in that: The thickness of the circular support structure (8) is not less than 1.2m, and the length of the circular support structure (8) is L3, L3≥L+1m, where L is the length of the deformation area (101) in meters.

5. The in-situ repair method for deformation of steel jacking pipe according to claim 1, characterized in that: The arc-shaped structure (601) is a semi-circular structure, and the two first support structures (602) are both horizontal structures, and the axial center line of the steel jacking pipe (1) is located on the plane where the two first support structures (602) are located.

6. The in-situ repair method for deformation of steel jacking pipe according to claim 1, characterized in that: In step S4, the support assembly (7) includes a first component (701) that fits against the inner wall of the steel jacking pipe (1), a second component (702) disposed at the center of the first component (701), and a support rod (703) that connects the first component (701) and the second component (702). Multiple support rods (703) are arranged around the axial center line of the steel jacking pipe (1) in a circumferential direction. The cross-sectional shape of the first component (701) is circular, and the diameter of the circle matches the inner diameter of the steel jacking pipe (1). The cross-sectional shape of the second component (702) is circular or rectangular, and the axial center line of the steel jacking pipe (1) passes through the center of the second component (702).

7. The in-situ repair method for deformation of steel jacking pipe according to claim 6, characterized in that: At least three support components (7) are provided at both ends of the deformation area (101) on the steel jacking pipe (1), and adjacent support components (7) are spaced apart.

8. The in-situ repair method for deformation of steel jacking pipe according to claim 1, characterized in that: It also includes step S5: continue the pipe jacking construction until it is completed, remove the support components (7) inside the steel pipe (1), install a concrete pipe (2) inside the steel pipe (1), fill the gap between the steel pipe (1) and the concrete pipe (2) with grout (12), and after the grout (12) reaches the design strength, remove the grouting pipe and support structure above the steel pipe (1), and restore the unloading area above the deformation area (101) to the height before unloading.

Images