A method for reinforcing damaged segments of shield tunnel

Abstract

The present invention discloses a method for reinforcing damaged segments of a shield tunnel, and relates to the technical field of shield tunnel construction. The method comprises reinforcing the inner side of the segment where the damaged part is located and the adjacent segments in the tunnel; grouting and reinforcing the soil in the first range outside the damaged part to a set thickness to form a first reinforcement layer; reinforcing the second range around the damaged part outside the tunnel to form a second reinforcement layer to the ground, and the outer edge of the second range is larger than the outer edge of the damaged part and smaller than the outer edge of the first range, and the first reinforcement layer and the second reinforcement layer partially overlap in the vertical direction; and repairing the damaged part in the tunnel. By reinforcing the inner side of the segment where the damaged part is located and the adjacent segments in the tunnel and reinforcing the soil outside the tunnel, the overall stability of the shield tunnel is ensured during the reinforcement process, which facilitates the reinforcement construction of the damaged part in the tunnel, and the segment repair is completed more quickly, with less impact on subway operation and the ground.

Description

Technical Field

[0001] The invention relates to the technical field of shield tunnel construction, and in particular to a method for reinforcing a damaged segment of a shield tunnel. Background Art

[0002] The buried depth of urban shield tunnels is generally 15 to 30 meters, which is relatively deep. After the construction of urban subway tunnels is completed, when construction is carried out along the subway line, the shield tunnel may be accidentally penetrated due to operational errors such as measurement and detection. The damaged segments need to be repaired as soon as possible to prevent the accident from further expanding. And because the penetration of the shield segment will damage the contact network at the top of the tunnel and affect the operation of the train, the segment needs to be repaired quickly to resume subway operation.

[0003] At present, after the shield segment is pierced, it is generally repaired by grouting and water-stopping in the tunnel and adding lining, but this is only for the case where the damage range is less than 50mm, and the vertical shaft is mostly used for repair. Due to the deep buried tunnel, the construction period of this plan is long and it cannot be repaired quickly, delaying the operation of the subway and causing certain social impacts. In addition, if water-rich poor geology is encountered, precipitation must be coordinated, and the cost is high. Summary of the invention

[0004] In view of the defects existing in the prior art, the purpose of the present invention is to provide a method for reinforcing damaged segments of a shield tunnel, so that the punctured shield segments can be temporarily sealed in a relatively short time, and the punctured shield segments can be quickly and effectively repaired from the outside of the tunnel under the premise of ensuring that the urban rail transit line does not stop operating or resumes operation as soon as possible, and the repaired shield tunnel meets the requirements of structural stress, waterproofing and durability.

[0005] In order to achieve the above purpose, the technical solution adopted by the present invention is:

[0006] A method for reinforcing a damaged segment of a shield tunnel is provided, comprising the following steps:

[0007] Reinforce the inner side of the segment where the damaged part is located and the adjacent segments in the tunnel;

[0008] Performing grouting reinforcement on the soil within the first range outside the damaged portion to a set thickness to form a first reinforcement layer;

[0009] Reinforce the second range around the damaged part outside the tunnel to form a second reinforcement layer reaching the ground, wherein the outer edge of the second range is larger than the outer edge of the damaged part and smaller than the outer edge of the first range, and the first reinforcement layer and the second reinforcement layer partially overlap in the vertical direction;

[0010] The above damaged parts are pre-treated and repaired in the tunnel.

[0011] In some optional embodiments, the above-mentioned pre-treatment of the damaged portion in the tunnel includes:

[0012] Chisel away the concrete at the damaged part until fresh concrete and main reinforcement of the segment are exposed;

[0013] A portion of the first reinforcement layer located in a third range around the damaged portion is chiseled off, with the outer edge of the third range being smaller than the outer edge of the first reinforcement layer, and a steel mesh and shotcrete are constructed on the surface of the reinforced soil after the chiseling off.

[0014] In some optional embodiments, after the steel mesh and shotcrete are constructed on the surface of the reinforced soil after chiseling, waterproof membrane is laid and interface agent is applied to the adjacent pipe segments.

[0015] In some optional embodiments, the third range extends mm outside the damaged portion along the outer wall of the pipe segment where the damaged portion is located, and the chiseled thickness extends mm outside the damaged portion along the radial direction of the pipe segment.

[0016] In some optional embodiments, the above-mentioned repairing of the damaged portion in the tunnel includes:

[0017] The main reinforcement of the damaged segment is tied with steel bars and welded to fix the segment where the damaged segment is located with the adjacent segment;

[0018] After the damaged portion is cast with concrete, reinforcement rings are applied to the pipe segments where the damaged portion is located and the adjacent pipe segments, and the reinforcement rings are connected to the corresponding pipe segments.

[0019] In some optional embodiments, the pipe segment where the damaged portion is located is connected to the adjacent pipe segment via straight bolts.

[0020] In some optional embodiments, after the reinforcement ring is constructed, epoxy resin is injected between the reinforcement ring and the pipe segment where the damaged portion is located and the adjacent pipe segments.

[0021] In some optional embodiments, the cast-in-place concrete uses concrete of the same grade as the damaged portion.

[0022] In some optional embodiments, the second reinforcement layer is reinforced from the ground to mm at the top of the tunnel using the MJS method; the set thickness is not less than mm.

[0023] In some optional embodiments, the soil within the first range outside the damaged portion is grout-reinforced by grouting through the grouting holes of the pipe segments.

[0024] Compared with the prior art, the advantages of the present invention are: by reinforcing the inner side of the pipe segment where the damaged part is located and the adjacent pipe segments in the tunnel and reinforcing the soil outside the tunnel, the overall stability of the shield tunnel is ensured during the reinforcement process, which facilitates the reinforcement construction of the pipe segment where the damaged part is located in the tunnel, and completes the pipe segment repair more quickly to restore the subway operation with less impact on the ground. It solves the problem that when repairing by the vertical shaft method, the construction period is long due to the deep burial depth of the tunnel, and the repair cannot be carried out quickly, which delays the subway operation and causes certain social impacts. In addition, if water-rich and unfavorable geology is encountered, precipitation must be coordinated, and the cost is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 Schematic diagram of step S1 in a method for reinforcing a damaged segment of a shield tunnel according to the present invention;

[0027] Figure 2 It is a schematic diagram of steps S2-S3 in a method for reinforcing a damaged segment of a shield tunnel according to the present invention;

[0028] Figure 3 Schematic diagram of step S41 in a method for reinforcing a damaged segment of a shield tunnel according to the present invention;

[0029] Figure 4 It is a schematic diagram of steps S42-S43 in a method for reinforcing a damaged segment of a shield tunnel according to the present invention;

[0030] Figure 5 for Figure 4 A partial enlarged schematic diagram of

[0031] Figure 6 It is a schematic diagram of step S44 in a method for reinforcing damaged segments of a shield tunnel according to the present invention.

[0032] In the figure: 1. damaged part; 11. main reinforcement of the segment; 2. adjacent segments; 3. first reinforcement layer; 4. second reinforcement layer; 5. reinforcement ring; 61. vertical steel beam; 62. horizontal beam; 63. longitudinal channel steel; 7. steel mesh; 8. bent and straight bolts; 9. annular steel. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0034] The embodiments of the present invention are further described in detail below with reference to the accompanying drawings.

[0035] The present application provides a method for reinforcing a damaged segment of a shield tunnel, comprising the following steps:

[0036] S1: Figure 1 As shown, the inner side of the segment where the damaged portion 1 is located and the adjacent segment 2 are reinforced in the tunnel.

[0037] In this example, the support and reinforcement area includes the ring where the damaged portion 1 is located, the first two rings of segments adjacent to the segment where the damaged portion 1 is located, and the last two rings of segments adjacent to the segment where the damaged portion 1 is located. First, the segment where the damaged portion 1 is located, the first two rings of segments, and the last two rings of segments, a total of five rings of segments, are reinforced with the inner arc surface tightly. Each ring of the segment is reinforced with two rings of ring steel 9 and the spacing between them is half of the ring width of the segment. Each ring of ring steel 9 is connected with several The vertical steel beams 61 are used to reinforce it, and several layers of horizontal beams 62 are connected between each vertical steel beam 61 and the annular steel 9, as well as between each vertical steel beam 61; finally, the annular steel 9 is connected together by several longitudinal channel steels 63, and each longitudinal channel steel 63 is also in close contact with the inner arc surface of the segment to form a detachable support truss to complete the support and reinforcement of the segment where the damaged part 1 is located, the first two rings of segments and the last two rings of segments, so as to prevent the segment from being damaged again during the subsequent reinforcement process.

[0038] S2: Figure 2 As shown, the soil within the first range outside the damaged portion 1 is reinforced by grouting to a set thickness to form a first reinforcement layer 3.

[0039] In some optional embodiments, the soil within the first range outside the damaged portion 1 is grout-reinforced by grouting through the grouting holes of the pipe segments.

[0040] In other embodiments, the method is not limited to reinforcing the soil within the first range, but grouting is performed using the grouting holes of the pipe segments, which can be operated in the hole and is simple and easy.

[0041] It can be understood that the above-mentioned first range is centered on the damaged part 1 and extends to the required range toward the surrounding soil. The extension area is determined according to the size and position of the damaged part 1. For example, when the area of ​​the damaged part 1 is large and is at a deeper position, the area of ​​the first range of the soil that needs to be reinforced needs to be set larger accordingly to ensure the stability of the soil around the damaged part 1.

[0042] S3: A second reinforcement layer 4 is formed outside the tunnel within a second range around the damaged portion 1 to the ground, and an outer edge of the second range is larger than an outer edge of the damaged portion 1 and smaller than an outer edge of the first range, and the first reinforcement layer 3 and the second reinforcement layer 4 are partially overlapped in the vertical direction.

[0043] In specific implementation, the reinforcement area is delineated with the vertical ground position of the damaged part 1 as the center, and reinforcement is carried out vertically downward from the ground to the top of the tunnel. The soil of the second reinforcement layer 4 is reinforced to fill the stratum lost after the pipe segment is punctured, reinforce the stratum, and have a certain water-proof effect. Similarly, the area of ​​the second range is specifically determined according to the size and position of the damaged part 1. For example, when the area of ​​the damaged part 1 is large and is at a deeper position, the area of ​​the second range of the soil that needs to be reinforced needs to be set larger accordingly to ensure the stability of the soil around the damaged part 1.

[0044] In some optional embodiments, the second reinforcement layer 4 is reinforced from the ground to 500 mm from the top of the tunnel using the MJS method, and the thickness is set to be no less than 2000 mm.

[0045] The MJS method (Metro Jet System, also known as the all-round high-pressure jet grouting method) uses a unique porous pipe structure to monitor the changes in the ground pressure in real time and ensure the balance of the ground pressure during the construction process by forced grouting, thereby reducing the impact of the construction on the surrounding environment. It is an all-round process that can be implemented in horizontal, inclined, and vertical construction. In this case, the MJS method is used to reinforce the soil in the second reinforcement layer 4, which can reduce the impact on the completed tunnel and the subway line in the tunnel.

[0046] Combined with the above-mentioned second reinforcement layer 4 reinforced to 500 mm from the top of the tunnel, the first reinforcement layer 3 and the second reinforcement layer 4 have an overlap of 1500 mm in the vertical direction, which has a better reinforcement effect on the soil around the damaged part 1.

[0047] S4: Pre-treat and repair the damaged portion 1 in the tunnel.

[0048] It can be understood that through the above steps S1 to S3, that is, the pipe segment where the damaged portion 1 is located and the adjacent two rings of pipe segments in front and behind are supported and reinforced in the tunnel, and at the same time, the soil outside the tunnel is reinforced with the damaged portion 1 as the center, so that the damaged portion 1 can be repaired directly in the hole. Compared with the traditional method of using a vertical shaft, the pipe segment can be repaired quickly with a smaller impact range and a lower cost.

[0049] In some optional embodiments, the above-mentioned pre-treatment of the damaged portion 1 in the tunnel includes:

[0050] S41: Figure 3 As shown, the concrete of the damaged portion 1 is chiseled off until the fresh concrete and the main reinforcement 11 of the segment at the damaged portion 1 are exposed.

[0051] Clean the rocks and soil at the damaged part 1 of the segment, and chisel away the concrete at the damaged part 1 until fresh concrete and the main reinforcement 11 of the segment are exposed at the damaged part 1, and sort out the broken reinforcement at the damaged part 1 to facilitate the subsequent repair work.

[0052] S42: Figure 4 As shown, part of the first reinforcement layer 3 located in the third range around the damaged portion 1 is chiseled off, and the outer edge of the third range is smaller than the outer edge of the first reinforcement layer 3, and a steel mesh 7 and shotcrete are constructed on the surface of the reinforced soil after chiseling off.

[0053] It can be understood that before repairing the damaged portion 1, the soil in the first reinforcement layer 3 around the damaged portion 1 should be chiseled off to a certain extent, and the reinforced soil after chiseling off should be reinforced for a second time to ensure that the soil around the damaged portion 1 has sufficient strength to assist in strengthening the repair effect of the damaged portion 1. It should be noted that the thickness of the chiseling off should be less than the above-mentioned set thickness.

[0054] In some optional embodiments, after the steel mesh and shotcrete are constructed on the surface of the reinforced soil after chiseling, waterproof membrane is laid and interface agent is applied to the adjacent pipe segments 2 .

[0055] Preferably, a waterproof roll can be arranged at the cross section of the damaged part 1, the purpose of which is to waterproof the end face of the damaged part 1; at the same time, it is convenient for the grouting pipe to bond with the waterproof roll at the damaged part 1 after injecting concrete, and the concrete at the damaged part 1 can seal the entire damaged part 1, thereby repairing the damaged part 1 and having the functions of reinforcement and water seepage prevention. The interface agent can be epoxy paint.

[0056] In some optional embodiments, the third range extends 100 mm outside the damaged portion 1 along the outer wall of the segment where the damaged portion 1 is located, and the chiseled thickness extends 300 mm outside the damaged portion 1 along the radial direction of the segment.

[0057] The specific settings of the third range and the chiseling thickness can be specifically set according to the actual size of the damaged portion 1 and the diameter and curvature of the entire pipe segment, and are not limited to the values ​​given in this application.

[0058] In some optional embodiments, the above-mentioned repairing of the damaged portion 1 in the tunnel includes:

[0059] S43: Figure 5 As shown, the main reinforcement 11 of the segment of the damaged portion 1 is tied with steel bars and welded, so that the segment where the damaged portion 1 is located is fixedly connected to the adjacent segment 2 .

[0060] It should be noted that after the steel bars are tied, they need to be connected to the main reinforcement 11 of the pipe segment where the damaged part 1 is located, which can be done by welding; and the pipe segment where the damaged part 1 is located needs to be connected to the adjacent pipe segment 2 to ensure the stability of the repaired pipe segment.

[0061] Preferably, in order to further ensure the strength and stability of the damaged portion 1 and meet the stress of the structure in the tunnel, the steel mesh 7 can also be connected to the main reinforcement 11 of the pipe segment and the newly tied steel bars at the damaged portion 1.

[0062] In some optional embodiments, the pipe segment where the damaged portion 1 is located is connected to the adjacent pipe segment 2 via a straight bolt 8 .

[0063] It should be noted that the straightening bolt 8 includes a bending portion and an inserting portion. In this example, the bending portion is inserted into the adjacent pipe segment 2, and the inserting portion is inserted into the pipe segment where the damaged portion 1 is located, thereby making the connection between the pipe segment where the damaged portion 1 is located and the adjacent pipe segment 2 more secure, thereby avoiding secondary rupture of the damaged portion 1.

[0064] S44: Figure 6 As shown, after the damaged portion 1 is cast with concrete, a reinforcement ring 5 is applied to the pipe segment where the damaged portion 1 is located and the adjacent pipe segment 2, and the reinforcement ring 5 is connected to the corresponding pipe segment.

[0065] Preferably, the molded concrete uses the same grade concrete as the damaged part 1 to ensure that the repaired segment is evenly stressed.

[0066] It can be understood that after the above-mentioned damaged part 1 is cast with concrete, in order to further ensure the stability of the tunnel structure and the strength of the pipe segment where the damaged part 1 is located, a reinforcement ring 5 is applied to the pipe segment where the damaged part 1 is located and the above-mentioned adjacent pipe segment 2, and the above-mentioned reinforcement ring 5 is connected to the corresponding pipe segment. The reinforcement ring 5 uses a plurality of arc-shaped steel plates, which are adjacent to each other in sequence to form a closed ring steel, and the interface of each arc-shaped steel plate is fixed by welding, and the reinforcement ring 5 is fixed to the corresponding pipe segment ring surface by chemical bolts to ensure that no secondary holes will appear at the damaged part 1. When the reinforcement ring 5 is subjected to pressure from the damaged part 1, the annular reinforcement ring 5 can disperse the pressure to various parts of the reinforcement ring 5, and then transmit it to various parts of the inner wall of the tunnel, so as to achieve pressure decomposition and transmission, and reduce the pressure on the damaged part 1.

[0067] In this example, the reinforcement rings 5 ​​are arranged on the segment where the damaged portion 1 is located and on the two adjacent segments in front and behind. The reinforcement ring 5 arranged on the segment where the damaged portion 1 is located is fully welded to the two adjacent reinforcement rings 5. The three reinforcement rings 5 ​​are welded into a whole, so that the pressure at the damaged portion 1 can be further decomposed and transferred to the adjacent segments.

[0068] In some optional embodiments, after the reinforcement ring 5 is constructed, epoxy resin is injected between the reinforcement ring 5 and the pipe segment where the damaged portion 1 is located and the adjacent pipe segment 2 .

[0069] Epoxy resin is filled between the reinforcement ring 5 and the pipe segment to bond the reinforcement ring 5 and the pipe segment together so that the reinforcement ring 5 and the pipe segment are in a state of continuous contact. Especially when the reinforcement ring 5 is subjected to unbalanced force, the reinforcement ring 5 can quickly transfer the pressure to the inner wall of the tunnel, making the force more uniform and achieving stable support for the pipe segment.

[0070] The present invention can repair the damaged part in the tunnel by reinforcing the damaged part in the tunnel and the soil outside the tunnel, thereby solving the problem that when the vertical shaft is used for repair, the construction period is long due to the deep burial depth of the tunnel, the repair cannot be carried out quickly, the subway operation is delayed, and a certain social impact is caused. In addition, if water-rich and unfavorable geology is encountered, precipitation is required, and the cost is high. The reinforced soil in the third range of the damaged part is reinforced twice to ensure the strength and support of the damaged part. The pipe segment where the damaged part is located and the adjacent pipe segment are connected by straight and bent bolts, so that the connection between the damaged part and the adjacent pipe segment is more firm. After the steel mesh and sprayed concrete are constructed on the surface of the reinforced soil after chiseling, the waterproof roll is laid and the interface agent is applied to the adjacent pipe segments, so that the repaired pipe segments meet the waterproof requirements. The pipe segment where the damaged part is located and the adjacent pipe segments are supported in an annular direction by a reinforcing ring, which solves the technical defect that the existing shield tunnel damaged pipe segment reinforcement technology cannot effectively prevent the damaged pipe segment from displacement and deformation at the damaged part.

[0071] In the description of the present application, it should be noted that the terms "upper", "lower", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0072] It should be noted that, in this application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0073] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A method for reinforcing damaged segments of a shield tunnel, characterized in that: The following steps are involved: Reinforcing the inner side of the segment where the damaged portion (1) is located and the adjacent segment (2) in the tunnel; Grouting is performed on the soil within a first range outside the damaged portion (1) to a set thickness to form a first reinforcement layer (3); Reinforcing a second range around the damaged portion (1) outside the tunnel to form a second reinforcement layer (4) reaching the ground, wherein the outer edge of the second range is larger than the outer edge of the damaged portion (1) and smaller than the outer edge of the first range, and the first reinforcement layer (3) and the second reinforcement layer (4) partially overlap in the vertical direction; Pre-treating and repairing the damaged portion (1) in the tunnel; Pre-treatment of the damaged portion (1) in the tunnel includes: Chiseling away the concrete of the damaged portion (1) until fresh concrete and the main reinforcement (11) of the segment are exposed at the damaged portion (1); Chiseling away a portion of the first reinforcement layer (3) located in a third range around the damaged portion (1), wherein the outer edge of the third range is smaller than the outer edge of the first reinforcement layer (3), and constructing a steel mesh (7) and shotcrete on the surface of the reinforced soil after the chiseling away; Repairing the damaged part (1) in the tunnel includes: The main reinforcement (11) of the pipe segment of the damaged portion (1) is tied with steel bars and welded to fix the pipe segment where the damaged portion (1) is located with the adjacent pipe segment (2); After the damaged portion (1) is cast with concrete, a reinforcement ring (5) is applied to the pipe segment where the damaged portion (1) is located and the adjacent pipe segment (2), and the reinforcement ring (5) is connected to the corresponding pipe segment.

2. The method for reinforcing a damaged segment of a shield tunnel according to claim 1, characterized in that: After the reinforcement mesh and shotcrete are constructed on the surface of the reinforced soil after the removal, waterproofing coiled material is laid and an interface agent is applied to the adjacent pipe segments (2).

3. The method for reinforcing damaged segments of a shield tunnel according to claim 1, characterized in that: The third range extends 100 mm outside the damaged portion (1) along the outer wall of the pipe segment where the damaged portion (1) is located, and the removed thickness extends 300 mm outside the damaged portion (1) along the radial direction of the pipe segment.

4. The method for reinforcing a damaged segment of a shield tunnel according to claim 1, characterized in that: The pipe segment where the damaged portion (1) is located is connected to the adjacent pipe segment (2) via a straight bolt (8).

5. The method for reinforcing a damaged segment of a shield tunnel according to claim 1, characterized in that: After the reinforcement ring (5) is constructed, epoxy resin is injected between the reinforcement ring (5) and the pipe segment where the damaged portion (1) is located and the adjacent pipe segment (2).

6. The method for reinforcing a damaged segment of a shield tunnel according to claim 1, characterized in that: The cast concrete adopts the same grade concrete as the damaged part (1).

7. The method for reinforcing a damaged segment of a shield tunnel according to claim 1, characterized in that: The second reinforcement layer (4) is reinforced from the ground to 500 mm from the top of the tunnel using the MJS method; the set thickness is not less than 2000 mm.

8. The method for reinforcing a damaged segment of a shield tunnel according to claim 1, characterized in that: The soil within a first range outside the damaged portion (1) is grout-reinforced by grouting through the grouting holes of the pipe segment.

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