A shield segment and a shield segment water leakage prevention method

Abstract

The application belongs to the technical field of tunnel grouting reinforcement, and discloses a shield segment and a shield segment water leakage prevention method. The shield segment comprises a shield segment body. A grouting pipe is arranged on the back surface of the shield segment body and close to the front side, the left side, the back side and the right side edge of the shield segment body. The two ends of each grouting pipe are closed, and a plurality of grouting holes are arranged on the side wall of the surrounding rock side of the pipe body. A drainage pipe is connected to each grouting pipe. The end of the drainage pipe is used as a grouting or water injection port, and is used for injecting grout into the grouting space between the shield segment body and the surrounding rock of the tunnel through the grouting pipe. Alternatively, the drainage pipe is used for guiding clean water into the grouting pipe. The shield segment and the shield segment water leakage prevention method are used for sectional grouting along the longitudinal direction of the tunnel, and the grouting is realized through the grouting pipe, so that the grouting sealing of the joint area is realized, the risk of water leakage of the joint area is reduced, and the grout in the grouting space is solidified into a continuous and complete consolidated body, so that the support is more stable.

Description

Technical Field

[0001] This invention belongs to the field of tunnel grouting reinforcement technology, specifically relating to a shield tunnel segment and a method for preventing water leakage in the shield tunnel segment. Background Technology

[0002] Shield tunneling technology, with its outstanding advantages of rapid construction, minimal disturbance to the surrounding strata, and high operational safety, is widely used in various underground infrastructure projects such as urban subway tunnels, cross-river and cross-sea tunnels, and underground integrated utility tunnels. The main support structure of a shield tunnel is precast reinforced concrete segment lining. On-site, individual shield segments are assembled into a ring structure using staggered joints and bolt fastening. The circumferential and longitudinal joints connecting the shield segments are the most critical weak points in the entire lining waterproofing system, and the sealing quality of these joints directly affects the overall service life and long-term operational safety of the tunnel. Currently, in tunnel construction, EPDM rubber and water-swellable rubber gaskets are commonly used as the main waterproofing structure for these joints. The pressure generated by the assembly and tightening of the segments causes the gaskets to elastically compress and deform, filling the joint gaps and blocking water seepage paths, thus forming the main waterproofing line of the tunnel lining.

[0003] In traditional shield tunnel segment assembly construction, deviations in the tunnel boring machine's (TBM) excavation posture and uneven output of the various propulsion jacks can lead to excessive longitudinal and circumferential misalignment of the TBM segments, inconsistent joint opening and closing, and chaotic gap distribution. This results in insufficient compaction and loose adhesion of the joint rubber seals, creating hidden seepage channels that are difficult to detect with the naked eye. Besides on-site construction factors, minor deformations during TBM segment transportation and hoisting further amplify and magnify these defects. After the tunnel is completed, under the continuous action of external loads such as soil and water pressure, uneven settlement deformation, and long-term vibration from vehicle traffic, the minor gaps left over from the construction phase will gradually widen and connect. Groundwater will continuously seep into the tunnel through weak points such as the segment's longitudinal and circumferential joints and bolt holes. Especially in complex geological environments such as water-rich soft soil and coastal high-pressure water, the high external water pressure will accelerate the development and evolution of seepage problems.

[0004] Currently, in the engineering field, most methods for addressing leakage at the joints of tunnel boring machine segments involve remedial measures such as post-operative grouting and sealing, which are typical post-treatment approaches. These repair methods can only temporarily seal existing leakage points and cannot fundamentally solve the core problems of insufficient segment assembly precision and joint sealing failure. The probability of recurrence is high, and the treatment effect is limited. Summary of the Invention

[0005] The purpose of this invention is to provide a shield tunnel segment and a method for preventing water leakage in the shield tunnel segment. The method involves grouting in sections along the longitudinal direction of the tunnel and grouting through grouting pipes to achieve grout sealing in the joint area, thereby reducing the risk of water leakage in the joint area. At the same time, the grout in the grouting space solidifies into a continuous and complete solidified body, making the support more stable.

[0006] The present invention adopts the following technical solution: a shield tunnel segment, including a shield tunnel segment body, and a grouting pipe is laid on the back of the shield tunnel segment body, and at the front, left, rear and right edges of the shield tunnel segment body respectively; both ends of each grouting pipe are closed, and multiple grouting holes are opened on the side wall of the pipe body on the side of the surrounding rock. Each grouting pipe is connected to a drain pipe, the end of which serves as a grouting or water injection port. This port is used to inject grout into the grouting space between the shield tunnel segment and the surrounding rock of the tunnel through each grouting pipe; or to introduce clean water into each grouting pipe. The shield tunnel segment body is used to install in the surrounding rock of the tunnel, forming a grouting space with the surrounding rock. Multiple shield tunnel segments are connected in sequence around the surrounding rock to form a ring segment structure. The side facing the working face is the front side, the side away from the working face is the rear side, the side facing the surrounding rock of the tunnel is the back side, and the side facing the tunnel is the front side.

[0007] Furthermore, the orientation of each grouting pipe is consistent with the side of the shield tunnel segment it is located on.

[0008] Furthermore, a central hole is provided in the center of the shield tunnel segment body, connecting the front and back sides, and the ends of each drainage pipe pass through the central hole to the front of the shield tunnel segment body.

[0009] Furthermore, a first groove is provided on the back side of the shield tunnel segment body, near the edge. The first groove surrounds the shield tunnel segment body and is connected end to end. Grouting pipes are correspondingly installed in the first grooves on the front, left, rear and right sides of the shield tunnel segment body.

[0010] Furthermore, on the back side of the shield tunnel segment body, a second groove is formed at its center, extending forward, backward, left and right respectively, and communicating with the first groove. Each drainage pipe is correspondingly arranged in the second groove.

[0011] The present invention also discloses a method for preventing water leakage in tunnel lining segments, based on a tunnel lining segment using any of the above-mentioned methods, comprising the following steps: Step 1: In the shield tunnel section that has been completed, the n rings of segments that are sequentially adjacent in the longitudinal direction are treated as a grouting operation group; where n is a natural number selected from 5 to 10.

[0012] Step 2: Select one ring segment structure adjacent to the grouting operation group in Step 1. In each ring segment structure, clean water is introduced into the grouting pipe through its corresponding drainage pipe, and the set water injection pressure is maintained. Under the set water injection pressure, clean water fills each grouting pipe. At the same time, the overflowing clean water gathers around the grouting pipe, forming a pressurized zone around the grouting pipe.

[0013] Step 3: In the grouting operation group in Step 1, the grout is introduced into the grouting pipe through its corresponding drainage pipe, and then into the grouting space enclosed by the grouting operation group and the surrounding rock of the tunnel, until the set grouting pressure is reached. In the grouting operation group, grout flows into the adjacent two ring segments and overflows the joint area. Between the grouting operation group and the adjacent ring segments, grout overflows from the front and rear sides of the grouting operation group. Under the constraint of the pressure zone, the grout flows into the grouting space near the edge of the adjacent ring segments, without entering the grouting pipes in the front and rear segments, and overflows the joint area between the grouting operation group and the adjacent ring segments.

[0014] Step 4: Select the next grouting operation group adjacent to the grouting operation group that has been completed, and repeat steps 2 and 3 until grouting is completed for the shield tunnel section that has been constructed.

[0015] Furthermore, in step three, after reaching the set grouting pressure, grouting is stopped first, and then the injection of clean water is stopped.

[0016] Furthermore, in step two, the set water injection pressure is 0.01~0.15MPa.

[0017] Furthermore, in step two, the drainage pipes of the front and rear ring segments are connected to the water injection system, through which clean water is injected into the grouting pipe from the drainage pipes.

[0018] Furthermore, each of the drainage pipes in the grouting operation group is connected to the grouting machine. The grout is injected into the grouting pipe through the drainage pipe by the grouting machine and then introduced into the grouting space.

[0019] The beneficial effects of this invention are: 1. Grouting pipes are laid out on the back side of the shield tunnel segment body near the edge. After multiple shield tunnel segments are installed in the surrounding rock of the tunnel, water is first injected into the grouting pipes of the adjacent ring segments in front and behind the grouting operation group, and a set low water injection pressure is maintained. Clean water fills each grouting pipe, and at the same time, the clean water overflows and gathers around the grouting pipe, forming a pressurized zone around the grouting pipe; then grouting is performed in the grouting space of the grouting operation group. Grout overflows from the front and rear sides of the grouting operation group, and the pressure in the pressurized zone is approximately Under the pressure constraint of the pressurized zone, the grout flows into the grouting space near the edge of each adjacent ring segment structure, without entering the grouting pipes within the ring segment structure. It overflows into the joint area between adjacent segments, but does not enter the grouting space on the back of the ring segments, preventing grout cross-flow and achieving grout sealing of the joint area, reducing water leakage. In the grouting operation group, the grout interacts between adjacent areas of two adjacent ring segments, forming a continuous and complete solidified body after solidification, resulting in more stable support. 2. Under the pressure constraint of the pressurized zone, the grout will not flow aimlessly in all directions, ensuring dense grouting at the joints of the grouting operation group and avoiding grout waste. 3. After one grouting operation group is completed, the next grouting operation group adjacent to it in the longitudinal direction is grouted. That is, segmented grouting is adopted in the longitudinal direction of the tunnel, which can effectively improve the efficiency of grouting construction. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the planar structure of the tunnel lining segment. Figure 2 This is a schematic diagram of the structure of the tunnel lining segment. Figure 3 This is a schematic diagram of the planar structure of adjacent tunnel lining segments; Figure 4 This is a schematic diagram of the segment structure; Figure 5 This is a cross-sectional view of the shield tunnel segment body along the second groove; Figure 6 This is a longitudinal cross-sectional view of the shield tunnel segment body along the second groove; Among them: 1. Shield tunnel segment body; 2. Grouting pipe; 3. Drainage pipe; 4. Central hole; 5. First groove; 6. Second groove; 7. Segment structure. Detailed Implementation

[0021] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0022] This invention discloses a tunnel segment, such as Figure 1 and 2As shown, the shield tunnel segment body 1 is included. On the back of the shield tunnel segment body 1, and near its front, left, rear and right edges, a grouting pipe 2 is laid. Both ends of each grouting pipe 2 are closed, and multiple grouting holes are opened on the side wall of the pipe body on the side of the surrounding rock. The direction of each grouting pipe 2 is consistent with the direction of the side of the shield tunnel segment body 1 on which it is located.

[0023] Each grouting pipe 2 is connected to a drainage pipe 3. The end of the drainage pipe 3 serves as a grouting or water injection port, used to inject grout into the grouting space between the shield tunnel segment 1 and the surrounding rock of the tunnel through each grouting pipe 2; or to introduce clean water into each grouting pipe 2. To ensure that the grout transported by the drainage pipe 3 is evenly distributed and flows as much as possible, the center of the grouting pipe 2 is connected to the corresponding drainage pipe 6. In this article, "clean water" refers to industrial water used at the construction site.

[0024] like Figure 3 and 4 As shown, the shield tunnel segment 1 is installed in the surrounding rock of the tunnel, forming a grouting space with the surrounding rock. Multiple shield tunnel segment 1s are sequentially connected around the surrounding rock to form a ring segment structure 7. The side of the shield tunnel segment 1 facing the tunnel face is the front side, the side away from the tunnel face is the rear side, the side facing the surrounding rock of the tunnel is the back side, and the side facing the tunnel is the front side.

[0025] The shield tunnel segment 1 is an arch shape that protrudes towards the surrounding rock of the tunnel. Multiple bolt connection holes are opened on the side of each shield tunnel segment 1. The specifications and sizes of the multiple shield tunnel segment 1 are not completely consistent. The specifications and sizes of each shield tunnel segment 1 are determined by the requirements of ring formation. According to different specifications, they are called standard blocks, adjacent blocks and wedge blocks.

[0026] As a specific embodiment, the outer diameter of the selected grouting pipe 2 is 25mm. A grouting hole with a diameter of 5mm is opened every 10cm to 20cm on the sidewall of each grouting pipe 2 located on the surrounding rock side. Adjacent grouting holes are staggered, and multiple grouting holes are arranged in a quincunx pattern to ensure uniform grout overflow. The grouting pipe 2 within the first groove 5 on each side includes multiple sections of axially connected perforated pipes. The joints of adjacent perforated pipe sections are threaded together. The joints are avoided at longitudinal joints, which refer to the joints between two adjacent shield tunnel segments 1 in the circumferential direction.

[0027] like Figure 5 and 6 As shown, a central hole 4 is provided in the center of the shield segment body 1, connecting the front and back sides. The ends of each drainage pipe 6 pass through the central hole 4 to the front of the shield segment body 1. After grouting is completed, the drainage pipe 3 is retracted into the central hole 4 of the shield segment body 1, and the central hole 4 is covered and sealed with a prefabricated cover.

[0028] On the back side of the shield tunnel segment 1, near the edge, a first groove 5 is formed. The first groove 5 surrounds the shield tunnel segment 1 and is connected end to end. Grouting pipes 2 are correspondingly arranged in the first grooves 5 on the front, left, rear, and right sides of the shield tunnel segment 1. The length of each grouting pipe 2 is consistent with the length of the first groove 5 on the side it is located on, so the ends of two grouting pipes 2 on adjacent sides fit together.

[0029] During grouting, in order to ensure that the back of the shield tunnel segment body 1 formed by the four grouting pipes 2 forms the largest possible grouting space, the first groove 5 is opened near the edge of the shield tunnel segment body 1, and the distance from the edge is generally 5cm to 10cm.

[0030] On the back side of the shield tunnel segment 1, a second groove 6 is formed from its center, extending forward, backward, left, and right, and communicating with the first groove 5. Each drainage pipe 6, connected to each grouting pipe 2, is located within the corresponding second groove 6. The first groove 5 and the second groove 6 are interconnected, forming a complete trench network for each shield tunnel segment 1. Each shield tunnel segment 1 is an independent grouting zone, enabling independent and controllable grouting of each shield tunnel segment 1.

[0031] The dimensions of the first groove 5 and the second groove 6 are designed to accommodate the grouting pipe 2 and the drainage pipe 6, and are generally about 3 cm wide and deep.

[0032] The aforementioned grouting pipe 2 is placed in the first groove 5. After it is in place, the gap between the grouting pipe 2 and the first groove 5 is filled with a flexible sealing material, but the grouting hole is not blocked, so as to prevent the gap from being blocked by the slag and grout during the assembly of the shield tunnel segment 1, the shield tunneling process, and the tunneling.

[0033] This invention also discloses a method for preventing water leakage in tunnel lining segments, based on the aforementioned type of tunnel lining segment, comprising the following steps: Step 1: On the surrounding rock inside the tunnel, assemble multiple shield tunnel segments 1 in sequence around the surrounding rock on the same cross section to form a ring segment structure 7; along the longitudinal direction of the tunnel, complete the installation of each ring segment structure 7 in sequence to form a shield tunnel section that has been completed. Adjacent ring segment structures 7 are fastened together with bolts.

[0034] In the shield tunnel section that has been completed, the n ring segments 7 that are sequentially adjacent in the longitudinal direction are regarded as a grouting operation group; where n is a natural number selected from 5 to 10, and the range of values ​​includes the end value.

[0035] Step 2: Select one adjacent ring-shaped pipe structure 7 from the grouting operation group in Step 1. Introduce clean water into the grouting pipe 2 through the drainage pipes 3 of each ring-shaped pipe structure 7, maintaining a set water injection pressure. Under the set water injection pressure, clean water fills each grouting pipe 2, and simultaneously overflows and converges around the circumference of the grouting pipe 2, forming a pressurized zone around the circumference of the grouting pipe 2. Circumferentially refers to the space surrounding each grouting pipe 2. The ends of the drainage pipes 3 of each ring-shaped pipe structure 7 are connected to a water injection system to inject water into each grouting pipe 2, maintaining a water injection pressure of 0.01~0.15MPa. During on-site construction, a grouting machine is used for the water injection system.

[0036] Step 3: In the grouting operation group in Step 1, each drainage pipe 3 is connected to the grouting machine. The grouting machine will introduce the grout into the grouting pipe 2 through each drainage pipe 3, and overflow from the grouting hole into the grouting space enclosed by the grouting operation group and the surrounding rock of the tunnel until the set grouting pressure is reached.

[0037] In the grouting operation group, the grout flows into the adjacent areas between two adjacent ring segments 7 and overflows the joint area; between the grouting operation group and each of the adjacent ring segments 7, the grout overflows from the front and rear sides of the grouting operation group. Under the constraint of the pressure zone, the grout flows into the grouting space near the edge of each of the adjacent ring segments 7, and does not enter the grouting pipes 2 in the front and rear segments 7, nor does it enter the grouting space on the back of each of the front and rear ring segments 7, and overflows the joint area between the grouting operation group and the adjacent ring segments 7.

[0038] When grouting the grouting space, after reaching the set grouting pressure, stop grouting first, and then stop injecting clean water. That is, turn off the grouting machine first, and then turn off the water injection system to ensure that the grout is under pressure constraint during the grouting process, so as to prevent the grout from entering the grouting pipe 2 of the front and rear ring segment structures 7, and also to prevent the grout from flowing around.

[0039] Step 4: Select the next grouting operation group adjacent to the grouting operation group that has been completed, and repeat steps 2 and 3 until grouting is completed for the shield tunnel section that has been constructed.

[0040] As a specific embodiment, five adjacent ring-shaped tunnel segments 7 in the longitudinal direction are selected as a grouting operation group, i.e., n is 5. The drainage pipes 3 in each of these five ring-shaped tunnel segments 7 are connected to the grouting machine pipelines, and the pipelines are numbered. The grouting sequence prioritizes grouting from lower to higher mileages in the tunnel, and for downhill tunnels, grouting proceeds from bottom to top. The number of grouting machines required is determined based on construction requirements, the number of shield tunnel segments 1, and the number of grouting ports of the selected grouting machines.

[0041] Before grouting, the drainage pipes 3 of the adjacent ring segments 7 of the grouting operation group are connected to the water injection system, and clean water is injected into each grouting pipe 2 to form a pressurized zone around each grouting pipe 2, which is equivalent to forming a sealing and stabilizing ring around the tunnel at the front and back of the grouting operation group.

[0042] The cement grout is mixed according to the design ratio, and the grout is filtered to remove large particles and prevent pipe blockage. The grouting machine, pressure gauge, flow meter, and valves are calibrated and qualified; at the same time, ensure that all grouting pipes are unobstructed.

[0043] The water system was activated, and water was injected into the adjacent ring segments 7 before and after the grouting work group. The pressure was gradually increased to a stable 0.1 MPa and maintained, forming a pressure-stabilizing ring before and after the grouting work group. The water formed a pressure barrier, preventing the cement grout in the grouting work group from leaking outwards and confining the grout within the grouting work group and its adjacent joint area.

[0044] Once the pressure of the sealing and stabilizing ring is confirmed to be stable at 0.1 MPa, the grouting machine is started to inject the prepared cement grout into the grouting operation team. During the grouting process, the pressure is increased slowly and in stages until the pressure in the grouting pipeline stabilizes at 0.5 MPa, at which point the pressure holding time is started.

[0045] The pressure holding and stabilization time is strictly controlled within three minutes. During the pressure holding stage, the pressure gauge reading is continuously monitored. If the pressure drops, grout is added appropriately to maintain the designed stable pressure value of 0.5 MPa. At the same time, the joints between adjacent shield tunnel segments 1 inside the tunnel are observed to determine whether there is any internal leakage of grout, segment cracking, or misalignment. When the three-minute pressure holding time is reached, the grouting machine is immediately stopped, all valves of the grouting operation group are quickly closed, and the internal grouting pressure is locked. After waiting for one minute to allow the grout in the grouting operation group to initially solidify and settle, the water injection system of the adjacent ring segments 7 is then closed, completing the grouting of this grouting operation group.

[0046] After the grouting work group completes the grouting, it will proceed in the longitudinal direction to grout the next adjacent grouting work group. It is not allowed to grout across multiple groups at the same time, until the grouting of the shield tunnel section that has been constructed is completed. After the grout solidifies, it forms a continuous and complete solidified body, making the support more stable.

Claims

1. A type of tunnel segment, characterized in that, The shield tunnel segment body (1) includes a grouting pipe (2) laid on the back of the shield tunnel segment body (1) and near its front, left, rear and right edges respectively; both ends of each grouting pipe (2) are closed, and multiple grouting holes are opened on the side wall of the pipe body on the side of the surrounding rock. Each of the grouting pipes (2) is connected to a drain pipe (3). The end of the drain pipe (3) serves as a grouting or water injection port, used to inject grout into the grouting space between the shield tunnel segment body (1) and the surrounding rock of the tunnel through each of the grouting pipes (2); or to introduce clean water into each of the grouting pipes (2). The shield tunnel segment body (1) is used to be installed in the surrounding rock of the tunnel to form a grouting space with the surrounding rock of the tunnel. Multiple shield tunnel segment bodies (1) are connected in sequence around the surrounding rock to form a ring segment structure (7). The side facing the working face is the front side, the side away from the working face is the rear side, the side facing the surrounding rock of the tunnel is the back side, and the side facing the tunnel is the front side.

2. A tunnel segment as described in claim 1, characterized in that, Each of the grouting pipes (2) is aligned with the side of the shield tunnel segment body (1) to which it is located.

3. A shield tunnel segment as described in claim 2, characterized in that, A central hole (4) is provided in the center of the shield tunnel segment body (1) to connect the front and back sides, and the ends of each of the drainage pipes (3) pass through the central hole (4) to the front of the shield tunnel segment body (1).

4. A tunnel segment as described in claim 3, characterized in that, On the back of the shield tunnel segment body (1), near the edge, a first groove (5) is provided. The first groove (5) surrounds the shield tunnel segment body (1) and is connected end to end. The grouting pipe (2) is correspondingly arranged in the first groove (5) on the front, left, rear and right sides of the shield tunnel segment body (1).

5. A tunnel segment as described in claim 4, characterized in that, On the back side of the shield tunnel segment body (1), a second groove (6) is provided at its center, extending forward, backward, left and right respectively, and communicating with the first groove (5). Each of the drainage pipes (3) is correspondingly arranged in the second groove (6).

6. A method for preventing water leakage in tunnel lining segments, characterized in that, Based on a tunnel segment using any one of claims 1-5, the process includes the following steps: Step 1: In the shield tunnel section where construction has been completed, take the n ring segments (7) that are sequentially adjacent in the longitudinal direction as a grouting operation group; where n is selected from natural numbers from 5 to 10; Step 2: Select one ring of pipe structure (7) adjacent to the grouting operation group in Step 1. In each ring of pipe structure (7), clean water is introduced into the grouting pipe (2) through the corresponding drainage pipe (3) and the set water injection pressure is maintained. Under the set water injection pressure, clean water fills each grouting pipe (2). At the same time, the overflowing clean water gathers around the grouting pipe (2) to form a pressurized area around the grouting pipe (2). Step 3: In the grouting operation group in Step 1, the grout is introduced into the grouting pipe (2) through the corresponding drainage pipe (3), and then introduced into the grouting space enclosed by the grouting operation group and the surrounding rock of the tunnel until the set grouting pressure is reached. In the grouting operation group, the grout flows into the adjacent areas of the adjacent rings of the segment structure (7) and overflows the joint area; between the grouting operation group and the adjacent rings of the segment structure (7), the grout overflows from the front and rear sides of the grouting operation group. Under the constraint of the pressure of the pressurized area, the grout flows into the grouting space near the edge of the adjacent rings of the segment structure (7) and does not enter the grouting pipe (2) in the segment structure (7) and overflows the joint area between the grouting operation group and the adjacent segment structure (7). Step 4: Select the next grouting operation group adjacent to the grouting operation group that has been completed, and repeat steps 2 and 3 until grouting is completed for the shield tunnel section that has been constructed.

7. A method for preventing water leakage in tunnel lining segments as described in claim 6, characterized in that, In step three, after the set grouting pressure is reached, grouting is stopped first, and then the injection of clean water is stopped.

8. A method for preventing water leakage in tunnel lining segments as described in claim 7, characterized in that, In step two, the water injection pressure is set to 0.01~0.15MPa.

9. A method for preventing water leakage in shield tunnel segments as described in claim 8, characterized in that, In step two, the drainage pipes (3) of the pipe segment structure (7) in the front and rear rings are connected to the water injection system, and clean water is injected into the grouting pipe (2) through the drainage pipes (3) by the water injection system.

10. A method for preventing water leakage in tunnel lining segments as described in claim 9, characterized in that, Each of the drainage pipes (3) in the grouting operation group is connected to the grouting machine. The grout is injected into the grouting pipe (2) through the drainage pipe (3) and introduced into the grouting space by the grouting machine.

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