Construction method for assembling tunnel segment and prefabricated lining

Abstract

The invention discloses a construction method for assembling a tunnel segment and a prefabricated lining, which relates to the technical field of tunnel segment construction and comprises the following steps: step 1, prefabricating the segment and the lining in advance in a factory; secondly, the prefabricated pipe pieces and linings are transported to a construction site, and comprehensive inspection is conducted; step 3, assembling the duct pieces; fourthly, the linings are assembled, specifically, the linings are sequentially installed, and the linings and the pipe pieces are fixedly connected; and fifthly, grouting and filling are conducted, specifically, grout is injected into a gap between the lining and the pipe piece, and an integral structure is formed. By the adoption of the construction method, the duct piece and the lining can be tightly bonded together to jointly bear the pressure of soil around the tunnel and other loads, meanwhile, the waterproof sealing effect is achieved, construction is easy and convenient, the structural stability is high, and the manufacturing cost is low.

Description

Technical Field

[0001] The present invention relates to the technical field of segment construction in tunnels, and particularly relates to a construction method for assembling tunnel segments and precast linings. Background Art

[0002] Tunnel segment construction is a key link in tunnel construction. Especially in tunnels constructed by the shield method, in order to improve the safety, durability, fire resistance, impact resistance and toughness of the tunnel segment structure, a lining structure needs to be set inside the tunnel segment. The existing connection methods between tunnel segments and precast linings mainly include bolt connection, steel bar connection, tenon and groove connection and grouting connection. Bolt connection usually involves pre-reserving bolt holes on the tunnel segment and the precast lining respectively, and fastening the two together by passing bolts through these holes. This method is relatively simple, but there are construction errors in the two bolt holes, and actual installation is relatively difficult. To solve this problem, indirect bolt connection is adopted during construction. First, connection sleeves or nuts are embedded in the segment, and corresponding bolt holes or connection components are set on the precast lining. During installation, the bolts are screwed into the sleeves or nuts to achieve connection, which can adapt to certain construction errors. However, this method increases the complexity of the structure, and there are protrusions of the connection structure on the surface of the lining, which is not conducive to subsequent construction. Steel bar connection is to drill holes in the segment first, clean them, inject structural adhesive, and then implant steel bars into the holes. After the structural adhesive cures, the steel bars form a reliable connection with the segment. Then, the precast lining is fixed on the segment through connection with these implanted steel bars (such as welding, binding, etc.). This method has low construction efficiency, complex coordination with other processes, and poor overall fatigue resistance after connection. Tenon and groove connection is to set convex tenons on the edge of the tunnel segment and grooves at the corresponding positions of the precast lining. During installation, the convex tenons are inserted into the grooves to form an interlocking connection. However, it has high requirements for the manufacturing precision of the structure, is difficult to adjust the position during installation, and has poor structural flexural rigidity. Summary of the Invention

[0003] The purpose of the present invention is to provide a construction method for assembling tunnel segments and precast linings. By adopting this construction method, the segments and the lining can be tightly bonded together to jointly bear the pressure of the surrounding soil mass of the tunnel and other loads, and at the same time, it also plays a role in waterproof sealing. The construction is simple and convenient, the structural stability is strong, and the manufacturing cost is low.

[0004] To achieve the above purpose, the present invention adopts the following technical solutions: A construction method for assembling tunnel segments and precast linings, the construction method comprising the following steps: Step 1, construction preparation. The segments and the lining are precast in the factory in advance. When precasting the segments, threaded sleeves are embedded and set at the preset positions of the segments. When precasting the lining, support sleeves are embedded and set at the positions on the lining that are adapted to the threaded sleeves. Step 2: Segment and Lining Inspection. Transport the precast segments and linings to the construction site, stack the segments and linings in sequence on the ground, paste a joint elastic gasket at the connection position of the segments, and inspect the appearance, dimensions, and markings of the segments and linings. Step 3: Segment Assembly. Lift the segments to the installation position. After accurate positioning, install the segments in sequence. For each installed segment, adjust its position to make it closely fit with the adjacent segments, and at the same time ensure that the bolt holes are aligned, insert the bolts and tighten them appropriately. Step 4: Lining Assembly. First, lift the first lining to the installation position. After accurate positioning, install a support plate in the support sleeve. There is an eccentric hole on the support plate. Rotate the support plate so that the eccentric hole aligns with the threaded sleeve. Use a screw rod to pass through the eccentric hole and connect it to the threaded sleeve. After rotating the screw rod to the preset position, install a connecting piece at the end of the screw rod, and fix the middle part of the screw rod and the connecting piece, and the edge of the connecting piece and the support plate by welding; then install the linings in sequence, install a support plate in each support sleeve, and connect them to the threaded sleeve through the screw rod; after all the linings are installed, fixedly install a sealing plate at the end of the support sleeve, adjust the gap between the lining and the segment to be uniform, and fix the sealing plate to the support sleeve by full welding. Step 5: Grouting Filling. Inject grout into the gap between the lining and the segment. The injected grout also fills the support sleeve at the same time. After the grout solidifies, it bonds the lining and the segment together to form an integral structure.

[0005] Preferably, in the above Step 1, at least two of the above support sleeves are provided on each of the above linings; structural protrusions are provided on the outer sides of both the above threaded sleeve and the above support sleeve.

[0006] Preferably, the diameter of the above support sleeve is not less than twice the diameter of the above threaded sleeve; an internal offset is provided at the end of the support sleeve.

[0007] Preferably, in the above Step 3, when installing the segment at the crown position, first measure the size of the opening at the top of the assembled segments. Installation can be carried out only when the size of the opening at the top of the assembled segments is slightly larger than the size of the segment to be installed.

[0008] Preferably, in the above Step 4, after the above sealing plate is fixedly installed, the inner wall of the sealing plate is in contact with the connecting piece.

[0009] Preferably, in the above Step 4, when assembling two adjacent above linings, seal the splicing joint with a sealant.

[0010] In the present invention, by adopting this construction method, the segment and the inner lining are rigidly connected mechanically through the screw, improving the flexural capacity of the overall structure. At the same time, through grouting, the segment and the inner lining are tightly bonded together to jointly bear the pressure of the soil around the tunnel and other loads, improving the force transmission effect. Meanwhile, it also plays a role in waterproof sealing and can prevent groundwater and the like from seeping into the tunnel interior.

[0011] The provided threaded sleeve and the support sleeve are installed in a prefabricated manner, which not only avoids damage to the segment and the inner lining caused by subsequent hole-opening operations but also ensures the reliability of the connection. The provided support sleeve can adapt to the installation error and manufacturing error of its central position relative to the threaded sleeve. By rotating the support plate, the eccentric hole corresponds to the threaded sleeve, and the end of the screw can be fixed, making the segment and the inner lining firmly connected.

[0012] The provided sealing plate seals and connects the end of the support sleeve to prevent leakage during grouting. After the sealing plate is fixedly installed, the inner wall of the sealing plate contacts the connecting piece, avoiding loosening of the screw and ensuring the structural strength of the connection. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a schematic diagram of the construction process of the present invention; Figure 2 is a partial schematic diagram of the connection state between the segment and the inner lining of the present invention; Figure 3 is an enlarged partial structure schematic diagram in the A direction of the present invention; Figure 4 is a top view schematic diagram of the support plate structure of the present invention; Figure 5 is a top view schematic diagram of the connecting piece structure of the present invention; Figure 6 is a sectional schematic diagram of the state of installing the screw in another embodiment of the support plate of the present invention; In the figure: 1, segment; 2, inner lining; 3, threaded sleeve; 4, support sleeve; 5, grouting joint; 6, support plate; 7, eccentric hole; 8, internal offset; 9, connecting boss; 10, structural protrusion; 11, screw; 12, connecting piece; 13, sealing plate. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0014] The following further describes the present invention with reference to the accompanying drawings: As Figures 1 to 6 shown, a construction method for assembling a tunnel segment and a prefabricated inner lining includes the following steps: Step 1, construction preparation: Prefabricate segment 1 and inner lining 2 in the factory in advance. When prefabricating segment 1, embed and set threaded sleeve 3 at the preset position of segment 1; when prefabricating inner lining 2, embed and set support sleeve 4 at the position on inner lining 2 that is adapted to threaded sleeve 3. Both segment 1 and inner lining 2 are of concrete structure. In a preferred embodiment, a structural protrusion 10 is provided on the outer side of threaded sleeve 3. The setting of structural protrusion 10 can improve the connection strength between threaded sleeve 3 and segment 1 and ensure the stability of the connection. At least two support sleeves 4 are provided on each inner lining 2. A structural protrusion 10 is also provided on the outer side of support sleeve 4. The setting of structural protrusion 10 can improve the connection strength between support sleeve 4 and prefabricated inner lining 2 and ensure the stability of the connection. The diameter of support sleeve 4 is not less than twice the diameter of threaded sleeve 3, and an internal offset 8 is provided at the end of support sleeve 4.

[0015] Step 2, inspection of segment 1 and inner lining 2: Transport the prefabricated segment 1 and inner lining 2 to the construction site, stack segment 1 and inner lining 2 in order on the ground, paste a joint elastic gasket at the connection position of segment 1, and conduct a comprehensive inspection of the appearance, dimensions, and markings of segment 1 and inner lining 2. Only after passing the inspection can subsequent operations be carried out. Before installation, conduct a quality inspection on the ring surface of the previous lining ring, including the flatness of the ring surface, whether there is damage, and whether the bolts are tightened. Remove the garbage and foreign objects in the ring surface of the previous ring and the shield tail to prevent affecting the segment assembly quality.

[0016] Step 3, segment 1 assembly: First, hoist the segment 1 to be installed to the installation position. After accurate positioning, install it through the segment erector, align it with the corresponding position of the previous ring of segment, insert and initially tighten the connection bolts; then sequentially install segment 1 in order. For each installed segment 1, adjust the position of segment 1 to make it closely fit with the adjacent segment 1, and at the same time ensure that the bolt holes are aligned, insert the bolts and tighten them appropriately; finally, after installing the last rear segment 1, tighten the connection bolts, and then install the next ring of segment 1. In specific implementation, the installation of inner lining 2 lags behind segment 1 by 100 rings, and the installation of inner lining 2 is carried out after ensuring the stable installation of segment 1.

[0017] Step 4, assembling the inner liner 2. Lift the inner liner 2 to the installation position. After accurate positioning, rotatably install the support plate 6 in the support sleeve 4. An eccentric hole 7 is provided on the support plate 6. Rotate the support plate 6 so that the eccentric hole 7 aligns with the threaded sleeve 3. Use the screw 11 to pass through the eccentric hole 7 and connect it to the threaded sleeve 3. After rotating the screw 11 to the preset position, install the connecting piece 12 at the end of the screw 11. Fix the connection between the middle of the screw 11 and the connecting piece 12 and the edge of the connecting piece 12 and the support plate 6 by welding. Then install the inner liner 2 in sequence. Install the support plate 6 in each support sleeve 4 and connect it to the threaded sleeve 3 through the screw 11. After all the inner liners 2 are installed, fixedly install the sealing plate 13 at the end of the support sleeve 3, and adjust the gap between the inner liner 2 and the segment 1 to form a uniform grouting seam 5. Finally, fixedly and hermetically connect the sealing plate 13 to the support sleeve 4 by full welding. Specifically, the eccentric hole 7 is a rectangular hole or a kidney-shaped hole. The support plate 6 is arranged on the internal offset 8. In a preferred embodiment, a connecting boss 9 is integrally provided on the support plate 6, and the eccentric hole 7 is arranged on the connecting boss 9. The setting of the connecting boss 9 provides a fixed installation space for the screw 11, which is convenient for locking and fixing with double nuts and reduces welding operations.

[0018] During specific installation, after the sealing plate 13 is fixedly installed, the inner wall of the sealing plate 13 contacts the connecting piece 12, restricting the displacement of the screw 11 and preventing loosening. When assembling two adjacent inner liners 2, seal the splicing seam with sealant. A connecting groove is provided in the support sleeve 4, and the support plate 6 is rotatably arranged in the connecting groove. Of course, the connecting groove can also be not provided. Rotate the support plate 6 to align the eccentric hole 7 with the center of the threaded sleeve 3, and then weld the support plate 6 in the support sleeve 4.

[0019] In a more preferred embodiment, at the corresponding position of a support sleeve 4, two or three threaded sleeves 3 are embedded in the segment 1. The interval between two adjacent threaded sleeves 3 is greater than the diameter of a support sleeve 4 and less than twice the diameter of the support sleeve 4, further improving the adaptability to installation errors and manufacturing errors.

[0020] Step 5, grouting and filling. Inject slurry into the grouting seam 5 between the inner liner 2 and the segment 4. The injected slurry also fills the inner cavity of the support sleeve 4. After the slurry solidifies, it tightly bonds the inner liner 2 and the segment 1 together, forming an integral structure that jointly bears the pressure of the surrounding soil and other loads of the tunnel, improving the force transmission effect, and at the same time playing a role in waterproof sealing, which can prevent groundwater and the like from seeping into the tunnel interior.

[0021] The above embodiments are only several explanations of the concept and implementation of the present invention, and do not limit it. Under the concept of the present invention, the technical solutions without substantial transformation are still within the protection scope.

Claims

1. A construction method for assembling tunnel segments and prefabricated linings, characterized in that: The construction method includes the following steps: Step 1, construction preparation: prefabricate segment linings in the factory in advance. When prefabricating segments, embed and set threaded sleeves at the preset positions of the segments; when prefabricating segment linings, embed and set support sleeves at the positions on the segment linings that are adapted to the threaded sleeves. Step 2, inspection of segments and segment linings: transport the prefabricated segments and segment linings to the construction site, stack the segments and segment linings in order on the ground, paste joint elastic gaskets at the connection positions of the segments, and inspect the appearance, dimensions, and markings of the segments and segment linings. Step 3, segment assembly: lift the segments to the installation position, after accurate positioning, install the segments in sequence. For each installed segment, adjust the position of the segment to make it closely fit with the adjacent segments, and at the same time ensure that the bolt holes are aligned, insert bolts and tighten them appropriately. Step 4, segment lining assembly: first lift the first segment lining to the installation position, after accurate positioning, rotatably install a support plate in the support sleeve. There is an eccentric hole on the support plate. Rotate the support plate so that the eccentric hole aligns with the threaded sleeve, use a screw rod to pass through the eccentric hole and connect it in the threaded sleeve. After rotating the screw rod to the preset position, install a connecting piece at the end of the screw rod, and fix the middle of the screw rod and the connecting piece, and the edge of the connecting piece and the support plate by welding; then install the segment linings in sequence, install a support plate in each support sleeve, and connect them to the threaded sleeve through screw rods; after all segment linings are installed, fixedly install a plugging plate at the end of the support sleeve, adjust the gap between the segment lining and the segment to be uniform, and fix the plugging plate to the support sleeve by full welding. Step 5, grouting filling: inject grout into the gap between the segment lining and the segment. The injected grout also fills the support sleeve at the same time. After the grout solidifies, bond the segment lining and the segment together to form an integral structure.

2. The construction method for assembling tunnel segments and precast linings according to claim 1, wherein: In the said Step 1, at least two of the said support sleeves are arranged on each of the said segment linings; structural protrusions are arranged on the outer sides of both the said threaded sleeves and the said support sleeves.

3. The construction method for assembling tunnel segments and prefabricated inner linings according to claim 1 or 2, characterized in that: The diameter of the said support sleeve is not less than twice the diameter of the said threaded sleeve; an internal stepped surface is arranged at the end of the support sleeve.

4. The construction method for assembling tunnel segments and precast linings according to claim 1, characterized in that: In the said Step 4, after the said plugging plate is fixedly installed, the inner wall of the plugging plate contacts the connecting piece.

5. The construction method for assembling tunnel segments and precast inner linings according to claim 1 or 4, characterized in that: In the said Step 4, when assembling two adjacent said segment linings, seal the splicing joint with sealant.

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