Shield tunnel assembly structure and installation method for soil layer with high groundwater level

Abstract

The application discloses a high-underground-water-level soil layer shield tunnel assembly structure and a mounting method, and relates to the technical field of tunnel construction. The high-underground-water-level soil layer shield tunnel assembly structure comprises a segment body, a reserved cavity is arranged in the middle part of the segment body, transverse stiffening ribs, longitudinal stiffening ribs and two prestressed tendons are arranged in the reserved cavity, two transverse slurry holes are arranged on the two sides of each transverse stiffening rib, longitudinal slurry holes are arranged on the top and the bottom of each longitudinal stiffening rib, and four slurry overflow holes are arranged on the top of the segment body. The high-underground-water-level soil layer shield tunnel assembly structure is characterized in that the segment body, the transverse stiffening ribs and the longitudinal stiffening ribs are arranged in cooperation, so that the problem of high transportation cost of the existing shield tunnel assembly segment is solved, the reserved cavity, the slurry hole, the slurry overflow hole and the prestressed tendon are arranged in cooperation, so that the integrity of the shield tunnel lining is effectively improved, and the problems of segment ring dislocation, floating and cracking are reduced.

Description

Technical Field

[0001] This invention relates to the field of tunnel construction technology, specifically to an assembly structure and installation method for shield tunnels in high groundwater level soil layers. Background Technology

[0002] The shield tunneling method is a fully mechanized construction method within the cut-and-cover tunneling technique. It involves advancing a shield machine underground, using the shield shell and tunnel segments to support the surrounding rock and prevent collapse into the tunnel. Simultaneously, cutting devices excavate the soil in front of the excavation face, transporting the excavated soil out of the tunnel using haulage machinery. Jacks then apply pressure from the rear to propel the tunnel forward, assembling precast concrete tunnel segments to form the tunnel structure. When shield tunnels traverse water-rich strata, the tunnel segments that have just detached from the shield tail often experience partial or complete floating, leading to segment misalignment, floating, and cracking, ultimately causing water seepage in the tunnel lining. Furthermore, existing shield tunnel segments are mostly manufactured using solid materials, increasing transportation costs.

[0003] Chinese Utility Model Patent Application No. CN201920130802.2 discloses a tenon-jointed shield tunnel segment and a tenon-jointed shield tunnel segment with tenon joints. The segment includes a body with a first protrusion at one circumferentially upward end and a first groove at the other circumferentially upward end that matches the first protrusion. Each longitudinal end face of the first protrusion has a first pin hole containing a first spring pin. A spring is fitted onto the spring pin, and a stop plate is located at the front end of the pin. This tenon-jointed shield tunnel segment and its tenon-jointed shield tunnel segment with tenon joints have solid bodies, resulting in significant weight, inconvenience for transportation, and high transportation costs. Furthermore, the method of connecting multiple segments into a ring using a tenon and mortise joint makes it difficult to guarantee the ring strength, and the tenon and mortise joints are insufficient to prevent water seepage.

[0004] Therefore, it is necessary to propose an assembly structure and installation method for shield tunnels in soil layers with high groundwater levels to solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to provide an assembly structure for shield tunnels in high groundwater level soil layers, so as to solve the problems mentioned in the background art, such as high transportation costs of existing shield tunnel assembly segments, easy occurrence of segment misalignment, floating and cracking.

[0006] To achieve the above objectives, the present invention provides the following technical solution: an assembly for a shield tunnel in a high groundwater level soil layer, comprising a segment body, wherein a reserved cavity is provided in the middle of the segment body, and the interior of the reserved cavity is provided with transverse stiffening ribs, longitudinal stiffening ribs and two prestressing tendons, two transverse grouting holes are provided on both sides of the transverse stiffening ribs, and longitudinal grouting holes are provided at the top and bottom of the longitudinal stiffening ribs, four overflow holes are provided at the top of the segment body, and a positioning groove, a positioning boss, four high-strength bolts and four grouting holes are provided at the bottom of the segment body, wherein a concave waterproof rubber layer is fixedly connected to the inner wall of the positioning groove, and a convex waterproof rubber layer is fixedly connected to the outer side of the positioning boss.

[0007] Preferably, both the main body of the tube segment and the reserved cavity are arc-shaped, and both sides of the reserved cavity penetrate the main body of the tube segment.

[0008] Preferably, both the transverse stiffening rib and the longitudinal stiffening rib are located in the middle of the reserved cavity, and the transverse stiffening rib and the longitudinal stiffening rib are fixed vertically.

[0009] Preferably, the two sides of the transverse stiffening rib are fixedly connected to the two sides of the reserved cavity, and the top and bottom of the longitudinal stiffening rib are fixedly connected to the inner wall of the reserved cavity.

[0010] Preferably, the two prestressing tendons are located on both sides of the longitudinal stiffening rib.

[0011] Preferably, the four transverse grout passages are symmetrically distributed, the two longitudinal grout passages are symmetrically distributed, and the diameters of the four transverse grout passages and the two longitudinal grout passages are equal.

[0012] Preferably, the bottom of each of the four overflow holes extends into the reserved cavity, and the top of each of the four grouting holes extends into the reserved cavity. The four overflow holes and the four grouting holes are symmetrically distributed.

[0013] Preferably, the positioning groove is located on one side of the bottom of the segment body, and the positioning boss is located on the other side of the bottom of the segment body, with the positioning groove and the positioning boss being adapted to each other.

[0014] An installation method for a shield tunnel assembly structure in soil layers with high groundwater levels includes the following steps:

[0015] Step 1: After the tunnel boring machine (TBM) advances, quickly assemble the tunnel segments into a ring. Starting from the standard block segment at the bottom, install the segments alternately on the left and right sides. In order to prevent damage to the segments and peeling of the sealing strips, the positioning bosses must be correctly inserted into the positioning grooves.

[0016] Step 2: Tighten the connecting bolts between the circumferential segments using a torque wrench;

[0017] Step 3: The tunnel boring machine continues to advance, and the connecting bolts are tightened again;

[0018] Step 4: Perform synchronous grouting behind the tunnel lining segments;

[0019] Step 5: Check whether the reserved cavity inside the segment is filled with grout. If insufficient grouting is found inside the segment, perform secondary grouting through the grouting hole.

[0020] Compared with the prior art, the present invention provides an assembly structure for shield tunnels in soil layers with high groundwater levels, which has the following beneficial effects:

[0021] 1. The assembly of this shield tunnel in a high groundwater level soil layer is achieved through the coordinated arrangement of the main body of the segment, the transverse stiffening ribs and the longitudinal stiffening ribs. The main body of the segment is hollow inside and fixedly connected with the transverse stiffening ribs and the longitudinal stiffening ribs. While ensuring the overall strength, the weight of the main body of the segment is reduced. Furthermore, the method of post-assembly casting is adopted, which effectively reduces transportation costs and solves the problem of high transportation costs for the assembled segments of existing shield tunnels.

[0022] 2. In the assembly of this shield tunnel in a high groundwater level soil layer, the reserved cavities inside multiple segments are connected by the coordinated setting of reserved cavities, grouting holes, overflow holes, and prestressing tendons. Grout can flow between multiple reserved cavities. Finally, the grout solidifies and the multiple segments form a whole. After the multiple segments are assembled and removed from the shield machine, the grout seeps out of the segments through the overflow holes, filling the gap between the segments and the surrounding soil. After completion, grout is injected synchronously behind the segments, which effectively improves the integrity of the shield tunnel lining and reduces problems such as segment misalignment, floating, and cracking.

[0023] 3. The assembly of the shield tunnel in the high groundwater level soil layer is facilitated by the combination of positioning grooves and positioning bosses. The positioning grooves are equipped with concave waterproof rubber layers inside and convex waterproof rubber layers are equipped with convex waterproof rubber layers outside. The combination of concave and convex waterproof rubber layers can ensure the seepage prevention at the joints and prevent external water from seeping into the segment rings.

[0024] 4. This invention proposes a novel shield tunnel segment form and its installation method. By adopting an assembly-post-pouring method, transportation costs are reduced, the integrity of the shield tunnel lining is effectively improved, and problems such as segment misalignment, floating, and cracking are reduced, thereby improving the lining's impermeability. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of the present invention;

[0026] Figure 2 This is a schematic front cross-sectional view of the structure of the present invention;

[0027] Figure 3This is a side cross-sectional view of the structure of the present invention;

[0028] Figure 4 This is a bottom view of the structure of the present invention.

[0029] In the diagram: 1. Main body of the segment; 11. Reserved cavity; 12. Bolt reserved hole; 13. Connecting bolt; 14. Grouting hole; 15. Overflow hole; 16. Prestressing tendon; 2. Transverse stiffening rib; 21. Transverse grouting hole; 3. Longitudinal stiffening rib; 31. Longitudinal grouting hole; 4. Positioning groove; 41. Concave waterproof rubber layer; 5. Positioning boss; 51. Convex waterproof rubber layer. Detailed Implementation

[0030] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0031] Please see Figure 1-4As shown, a shield tunnel assembly structure for high groundwater level soil layers includes a segment body 1. A reserved cavity 11 is provided in the middle of the segment body 1. The reserved cavity 11 reduces the self-weight of the segment body 1, reducing the manpower, material resources, and financial resources required for transportation. Both the segment body 1 and the reserved cavity 11 are arc-shaped, with both sides of the reserved cavity 11 penetrating the segment body 1. The segment body 1 is part of the tunnel's circular lining and is a factory-prefabricated standard component. The production of the segment body 1 uses high-strength impermeable concrete to ensure reliable load-bearing capacity and waterproof performance. Production mainly utilizes precast segment molds, which are formed after sealed concrete pouring. The curvature of the segment body 1 is determined according to the tunnel diameter, the width can be selected within the range of 1m-1.5m, and the thickness depends on the segment diameter. The stress distribution of the main body 1 is determined. The interior of the reserved cavity 11 is equipped with transverse stiffening ribs 2, longitudinal stiffening ribs 3, and two prestressing tendons 16. The transverse stiffening ribs 2 and longitudinal stiffening ribs 3 prevent damage to the main body 1 during transportation or stacking. Through the coordinated arrangement of the main body 1, transverse stiffening ribs 2, and longitudinal stiffening ribs 3, the main body 1 is hollow inside and fixedly connected with transverse stiffening ribs 2 and longitudinal stiffening ribs 3. This reduces the weight of the main body 1 while ensuring overall strength. Furthermore, the use of post-assembly casting effectively reduces transportation costs and solves the problem of high transportation costs for assembled tunnel segments. The transverse stiffening ribs 2 and longitudinal stiffening ribs 3 are both located in the middle of the reserved cavity 11 and are vertically fixed. The two sides of the stiffening rib 2 are fixedly connected to the two sides of the reserved cavity 11. The top and bottom of the longitudinal stiffening rib 3 are fixedly connected to the inner wall of the reserved cavity 11. The two prestressing tendons 16 are located below the transverse stiffening rib 2 and on both sides of the longitudinal stiffening rib 3. The length of the two prestressing tendons 16 is greater than the arc length of the segment body 1. The prestressing tendons 16 are determined according to the tunnel bending moment at the location of the segment body 1. Two transverse grouting holes 21 are opened on both sides of the transverse stiffening rib 2. Longitudinal grouting holes 31 are opened on the top and bottom of the longitudinal stiffening rib 3. The four transverse grouting holes 21 and the two longitudinal grouting holes 31 are symmetrically distributed. The diameters of the four transverse grouting holes 21 and the two longitudinal grouting holes 31 are equal. The top of the main body 1 has four overflow holes 15, and the bottom of the main body 1 has a positioning groove 4, a positioning boss 5, four bolt pre-drilled holes 12, and four grouting holes 14. The bottom of the four overflow holes 15 extends into the reserved cavity 11, and the top of the four bolt pre-drilled holes 12 and the four grouting holes 14 extend into the reserved cavity 11. The four overflow holes 15, bolt pre-drilled holes 12, and four grouting holes 14 are symmetrically distributed. Each of the four grouting holes 14 is equipped with a check valve, which allows grout to be injected but not grout or groundwater to flow out. Through the coordinated arrangement of the reserved cavity 11, grouting holes 14, overflow holes 15, and prestressing tendons 16, the reserved cavities 11 inside the multiple main bodies 1 of the main body form a connected body, and the grout can flow between the multiple reserved cavities 11.Finally, the grout solidifies, forming a single unit from multiple tunnel segments 1. After the multiple tunnel segments 1 are assembled and removed from the tunnel boring machine, the grout seeps out of the tunnel segments 1 through the overflow hole 15, filling the gap between the tunnel segment ring and the surrounding soil. Afterwards, grout is injected simultaneously behind the tunnel segments, effectively improving the integrity of the tunnel lining and reducing problems such as segment ring misalignment, floating, and cracking. A concave waterproof rubber layer 41 is fixedly connected to the inner wall of the positioning groove 4, and a convex waterproof rubber layer 51 is fixedly connected to the outer side of the positioning boss 5. The positioning groove 4 is located on one side of the bottom of the tunnel segment 1, and the positioning boss... Located on the other side of the bottom of the segment body 1, the positioning groove 4 and the positioning boss 5 are adapted to each other. The four bolt pre-drilled holes 12 are all threaded with connecting bolts 13, which can be straight or bent bolts. The matching arrangement of the positioning groove 4 and the positioning boss 5 facilitates the assembly of multiple segment bodies 1. The positioning groove 4 has a concave waterproof rubber layer 41 inside, and the positioning boss 5 has a convex waterproof rubber layer 51 on the outside. The cooperation between the concave waterproof rubber layer 41 and the convex waterproof rubber layer 51 ensures the impermeability of the joint, preventing external moisture from seeping into the segment ring.

[0032] An installation method for a shield tunnel assembly structure in a high groundwater level soil layer, characterized by the following steps:

[0033] Step 1: After the tunnel boring machine (TBM) advances, quickly assemble the tunnel segments into a ring. Starting from the standard block segment at the bottom, install the segments alternately on the left and right sides. In order to prevent damage to the segments and peeling of the sealing strips, the positioning bosses must be correctly inserted into the positioning grooves.

[0034] Step 2: Tighten the connecting bolts between the circumferential segments using a torque wrench;

[0035] Step 3: The tunnel boring machine continues to advance, and the connecting bolts are tightened again;

[0036] Step 4: Perform synchronous grouting behind the tunnel lining segments;

[0037] Step 5: Check whether the reserved cavity inside the segment is filled with grout. If insufficient grouting is found inside the segment, perform secondary grouting through the grouting hole.

[0038] Specifically, after the tunnel boring machine (TBM) advances, multiple segment bodies 1 are quickly assembled into a ring. Starting from the bottom segment body 1, segment bodies 1 are installed alternately on the left and right sides. To prevent damage to the segment body 1 or peeling of the sealing strip, it is essential to ensure that the positioning boss 5 is correctly inserted into the positioning groove 4. The connecting bolts 13 between the segment bodies 1 are tightened with a torque wrench. As the TBM continues to advance, the connecting bolts 13 are tightened again. Grout is injected into the reserved cavity 11 inside the segment body 1 through the grouting hole 14. The grout used is a grout with micro-expansion properties and low bleeding characteristics. The grout solidifies with high strength and hardness. The reserved cavity 11 is checked to ensure it is filled with grout. If insufficient grouting is found inside the reserved cavity 11, secondary grouting is carried out through the grouting hole 14. After the multiple segment bodies 1 are assembled, the reserved cavities 11 inside the multiple segment bodies 1 form a connected body. The grout can flow between the multiple reserved cavities 11. Finally, the grout solidifies and the multiple segment bodies 1 rings form a whole. After the multiple segment bodies 1 are assembled and removed from the tunnel boring machine, the grout seeps out of the segment body 1 through the overflow hole 15, filling the gap between the segment ring and the surrounding soil layer. After completion, grouting is carried out synchronously behind the segment. The contact surfaces of the positioning groove 4 and the positioning boss 5 are respectively provided with a concave waterproof rubber layer 41 and a convex waterproof rubber layer 51 to ensure the seepage prevention at the joint.

[0039] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A shield tunnel assembly structure for a high groundwater level soil layer, comprising a segment body (1) which is a concrete structure, characterized in that: The middle part of the pipe piece body (1) is provided with a reserved cavity (11), both sides of the reserved cavity (11) penetrate through the pipe piece body (1), the reserved cavities (11) in the plurality of pipe piece bodies (1) can form a communication body, the slurry can flow between the plurality of reserved cavities (11), and the slurry solidification makes the plurality of pipe piece bodies (11) circumferentially form a whole, the inside of the reserved cavity (11) is provided with a transverse stiffening rib (2), a longitudinal stiffening rib (3) and two prestressed tendons (16), the transverse stiffening rib (2) and the longitudinal stiffening rib (3) are fixedly connected, the two sides of the transverse stiffening rib (2) are fixedly connected with the two sides of the inside of the reserved cavity (11), the top and the bottom of the longitudinal stiffening rib (3) are fixedly connected with the inner wall of the reserved cavity (11), the two prestressed tendons (16) are located on the two sides of the longitudinal stiffening rib (3), and the lengths of the two prestressed tendons (16) are greater than the arc length of the pipe piece body (1), both sides of the transverse stiffening rib (2) are provided with two transverse slurry through holes (21), the top and the bottom of the longitudinal stiffening rib (3) are provided with longitudinal slurry through holes (31), the top of the pipe piece body (1) is provided with four slurry overflow holes (15), and the bottom of the pipe piece body (1) is provided with a positioning groove (4), a positioning boss (5), four high-strength bolts (13) and four grouting holes (14), the inner wall of the positioning groove (4) is fixedly connected with a concave waterproof rubber layer (41), and the outer side of the positioning boss (5) is fixedly connected with a convex waterproof rubber layer (51).

2. The shield tunnel assembly structure for soil layer with high groundwater level according to claim 1, characterized in that: The pipe piece body (1) and the reserved cavity (11) are arc-shaped.

3. The shield tunnel assembly structure for soil layer with high groundwater level according to claim 1, characterized in that: The transverse stiffening rib (2) and the longitudinal stiffening rib (3) are located in the middle part of the reserved cavity (11).

4. The shield tunnel assembly structure for soil layer with high ground water level according to claim 1, characterized in that: The four transverse slurry through holes (21) are symmetrically distributed, the two longitudinal slurry through holes (31) are symmetrically distributed, and the diameters of the four transverse slurry through holes (21) and the two longitudinal slurry through holes (31) are equal.

5. The shield tunnel assembly structure for soil layer with high ground water level according to claim 1, characterized in that: The bottoms of the four slurry overflow holes (15) extend into the reserved cavity (11), the tops of the four grouting holes (14) extend into the reserved cavity (11), and the four slurry overflow holes (15) and the four grouting holes (14) are symmetrically distributed.

6. The shield tunnel assembly structure for soil layer with high ground water level according to claim 1, characterized in that: The positioning groove (4) is located on one side of the bottom of the pipe piece body (1), the positioning boss (5) is located on the other side of the bottom of the pipe piece body (1), and the positioning groove (4) is matched with the positioning boss (5).

7. A method of installing a shield tunnel assembly structure in a high groundwater soil layer, characterized by, The method comprises the following steps: Step 1: after the shield propulsion is completed, the pipe pieces are rapidly assembled into a ring, starting from the lower standard block pipe piece, and the pipe pieces are alternately installed on the left and right sides in sequence, in order to prevent pipe piece damage and sealing strip peeling, the positioning boss needs to be correctly inserted into the positioning groove; Step 2: a torque wrench is used to fasten the connecting bolts between the circumferential pipe pieces; Step 3: the shield continues to advance, and the connecting bolts are retightened; Step 4: Implement the synchronous grouting work behind the pipe piece; through the grouting hole (14), grout is injected into the reserved cavity (11) inside the pipe piece body (1), the reserved cavities (11) inside the plurality of pipe piece bodies (1) form a communication body, and the grout can flow between the plurality of reserved cavities (11). Finally, the grout solidifies to form a whole in the circumferential direction of the plurality of pipe piece bodies (1). After the plurality of pipe piece bodies (1) are assembled and removed from the shield machine, the grout seeps out of the pipe piece body (1) through the overflow hole (15), so that the grout fills the gap between the pipe piece ring and the surrounding soil layer, and the synchronous grouting behind the pipe piece is completed. Step 5: Check whether the reserved cavity inside the pipe piece is filled with grout. If it is found that the grouting inside the pipe piece is insufficient, secondary grouting is performed through the grouting hole.

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