Tunnel inter-circumferential support longitudinal beam system and construction method thereof

Abstract

A tunnel ring inter-support longitudinal beam system comprises several left tunnel ring prefabricated top pipe pieces fixed side by side, several right tunnel ring prefabricated top pipe pieces fixed side by side, several top post-poured steel concrete beams and a top post-poured U-shaped beam; a top left fixing block is protruded downward at the right end of the left tunnel ring prefabricated top pipe piece; a top right fixing block is protruded downward at the left end of the right tunnel ring prefabricated top pipe piece; several top working holes are formed in the top left fixing block and the top right fixing block respectively; the several top post-poured steel concrete beams are poured and formed in the several top working holes; the top post-poured U-shaped beam is poured and formed at the lower part of the left tunnel ring prefabricated top pipe piece and the right tunnel ring prefabricated top pipe piece; the left end of the top post-poured U-shaped beam is pressed against the left side of the top left fixing block, and the right end thereof is pressed against the right side of the top right fixing block. The tunnel ring inter-support longitudinal beam system forms longitudinal support between tunnel rings, guarantees the inter-ring connecting strength and rigidity, and guarantees the structural safety of the large-section rectangular tunnel.

Description

Technical Field

[0001] This invention relates to a tunnel construction technology. Background Technology

[0002] The construction of large-section rectangular tunnels by cutting and excavating is a new technology with no prior engineering experience in China. There is no technical solution to the problem of insufficient rigidity and inter-ring connection at pipeline junctions during the construction of tunnels by cutting and excavating. Summary of the Invention

[0003] The technical problem to be solved by this invention is that, in the prior art, the inter-ring connection and stiffness at the pipeline junction point during the underground excavation of large-section rectangular tunnels are insufficient to form a structural system with the columns. This invention proposes a tunnel inter-ring support longitudinal beam system to provide longitudinal support between the tunnel rings, ensuring the strength and stiffness of the inter-ring connection at the pipeline junction point, and forming a beam-column internal support system in conjunction with the columns, thus ensuring the structural safety of large-section rectangular tunnels.

[0004] To solve the above-mentioned technical problems, the present invention proposes the following technical solution: a tunnel ring inter-support longitudinal beam system, comprising several precast jacking segments of the left tunnel ring fixed in parallel, several precast jacking segments of the right tunnel ring fixed in parallel, several top post-cast steel-concrete beams and top post-cast U-shaped beams; Several right tunnel ring precast jacking segments are installed and fixed adjacent to the right side of several left tunnel ring precast jacking segments; A top left fixing block protrudes downward from the right end of the precast jacking segment of the left tunnel ring; A top right fixing block protrudes downward from the left end of the precast jacking segment of the right tunnel ring; Several top working holes are respectively opened in the top left fixing block and the top right fixing block; Several post-cast steel-concrete composite beams were cast into several top working holes; Each top post-cast steel-concrete beam includes an I-beam located in the top working hole and post-cast concrete poured between the I-beam and the top working hole; The top post-cast U-shaped beam includes a steel plate encasing the top U-shaped beam and top post-cast concrete; the left and right ends of the steel plate encasing the top U-shaped beam are respectively installed and fixed on the bottom wall of the precast jacking segment of the left tunnel ring and the bottom wall of the precast jacking segment of the right tunnel ring, and the middle protruding part is suspended below the top left fixing block and the top right fixing block. The top post-cast concrete was poured between the steel plate encasing the top U-shaped beam and the precast jacking segments of the left and right tunnel rings. The top post-cast U-shaped beam is formed at the bottom of the precast jacking segments of the left tunnel ring and the precast jacking segments of the right tunnel ring; The left end of the top post-cast U-shaped beam presses against the left side of the top left fixing block, and its right end presses against the right side of the top right fixing block, thereby firmly connecting the left tunnel ring precast jacking segment and the right tunnel ring precast jacking segment.

[0005] A further limitation of the above technical solution is that an upper joint is left between the precast jacking segments of the left tunnel ring and the precast jacking segments of the right tunnel ring, and epoxy resin is provided in the upper joint.

[0006] A further limitation of the above technical solution is that the bottom of the top left fixing block and the bottom of the segment to its left are both pre-embedded with top left anchor bars, the bottom of the top right fixing block and the bottom of the segment to its right are both pre-embedded with top right anchor bars, and the steel plate encasing the top U-shaped beam covers the top left anchor bars and the top right anchor bars within it.

[0007] A further limitation of the above technical solution is that a pre-reserved steel plate for the top working hole is fixedly installed on the inner wall of the top working hole, and the post-cast concrete is poured between the I-beam and the pre-reserved steel plate for the top working hole.

[0008] A further limitation of the above technical solution is that the widths of the precast jacking segments of the left tunnel ring and the right tunnel ring are the same.

[0009] A further limitation of the above technical solution is that the top post-cast U-shaped beam also includes a top U-shaped beam reinforcement cage, which is installed between the outer steel plate of the top U-shaped beam and the precast jacking segments of the left tunnel ring and the precast jacking segments of the right tunnel ring.

[0010] A further limitation of the above technical solution is that the bottom wall of the steel plate covering the top U-shaped beam is provided with upwardly extending top steel plate anchors.

[0011] To solve the above-mentioned technical problems, the present invention proposes the following technical solution: a construction method for a tunnel inter-ring support longitudinal beam system, comprising the following steps: Step 1: Fix several left tunnel ring precast jacking segments and several right tunnel ring precast jacking segments side by side, and install and fix several right tunnel ring precast jacking segments close to the right side of several left tunnel ring precast jacking segments. Step 2: Insert I-beams into each top working hole of the precast jacking segments of the left and right tunnel rings. The I-beams are inserted simultaneously from the first and last rings at both ends of the tunnel. After completion, check whether the total insertion length of the I-beams meets the standard. After the inspection, inject high-strength self-compacting concrete to form several top post-cast steel-concrete beams. Step 3: Install and fix the top U-shaped beam steel cage and the outer steel plate of the top U-shaped beam to the lower part of the precast jacking segments of the left tunnel ring and the right tunnel ring; Step 4: High-strength self-compacting concrete is injected into the space formed by the steel plate encasing the top U-shaped beam, the precast jacking segments of the left tunnel ring, and the precast jacking segments of the right tunnel ring to form the top post-cast U-shaped beam; Step 5: When the strength of the top post-cast steel-concrete beam and the top post-cast U-shaped beam reaches the design requirements, the tunnel inter-ring support longitudinal beam system is formed.

[0012] A further limitation of the above technical solution is that, between step 1 and step 2, the following steps are also included: injecting waterproofing agent into the upper joints between a number of precast jacking segments of the left tunnel ring and a number of precast jacking segments of the right tunnel ring. When injecting the waterproofing agent, it should start from the middle ring of the tunnel and be injected ring by ring towards the first and last rings at both ends of the tunnel. After the waterproofing agent is injected, check whether there are cavities in the upper joints between the precast jacking segments of the left tunnel ring and a number of precast jacking segments of the right tunnel ring. If there are cavities, inject the waterproofing agent a second time. A further limitation of the above technical solution is that the waterproofing agent is epoxy resin.

[0013] Compared with the prior art, the present invention has the following beneficial effects: The longitudinal beam system for tunnel inter-ring support of the present invention provides longitudinal support between tunnel rings, ensures the strength and rigidity of the inter-ring connection at pipeline junctions, and forms a beam-column internal support system in conjunction with the columns, ensuring the structural safety of large-section rectangular tunnels. Attached Figure Description

[0014] Figure 1 This is a cross-sectional view of a subway station constructed using the cut-and-cover method.

[0015] Figure 2 This is a cross-sectional view of the tunnel ring support longitudinal beam system used at the bottom of the aforementioned subway underground stations.

[0016] Figure 3 This is a cross-sectional view of the tunnel ring support longitudinal beam system used at the top of the aforementioned subway underground stations.

[0017] Figure 4 This is a cross-sectional view of the precast bottom segment of the left tunnel ring.

[0018] Figure 5 This is a cross-sectional view of the precast bottom segment of the right tunnel ring.

[0019] Figure 6 This is a cross-sectional view of the precast jacking segments of the left tunnel ring.

[0020] Figure 7 This is a cross-sectional view of the precast jacking segments of the right tunnel ring.

[0021] Figure 8 This is a sectional view of the bottom post-cast steel-concrete beam.

[0022] Figure 9This is a sectional view of the top post-cast steel-concrete composite beam.

[0023] Figure 10 This is a sectional view of the bottom post-cast U-shaped beam.

[0024] Figure 11 This is a sectional view of the top post-cast U-shaped beam. Detailed Implementation

[0025] Please see Figures 1 to 11 A type of subway tunnel station includes several precast bottom segments 1 of the left tunnel ring installed side by side, several precast bottom segments 2 of the right tunnel ring installed side by side on the right side of the precast bottom segments 1 of the left tunnel ring, several precast side segments 3 of the left tunnel ring installed side by side vertically fixed to the left end of the precast bottom segments 1 of the left tunnel ring, several precast side segments 4 of the right tunnel ring installed side by side vertically fixed to the right end of the precast bottom segments 2 of the right tunnel ring, several precast top segments 5 of the left tunnel ring installed side by side on top of the precast side segments 3 of the left tunnel ring, several precast top segments 6 of the right tunnel ring installed side by side on top of the precast side segments 4 of the right tunnel ring, two bottom post-cast steel-concrete beams 7, bottom post-cast U-shaped beams 8, two top post-cast steel-concrete beams 9, top post-cast U-shaped beams 10, and several permanent columns (not shown in the figure).

[0026] Two bottom-cast steel-concrete composite beams 7 were respectively cast at the right end of the precast bottom segment 1 of the left tunnel ring and the left end of the precast bottom segment 2 of the right tunnel ring.

[0027] Two post-cast steel-concrete composite beams 9 were cast at the right end of the precast jacking segment 5 of the left tunnel ring and the left end of the precast jacking segment 6 of the right tunnel ring, respectively.

[0028] The bottom post-cast U-shaped beam 8 firmly connects the precast bottom segment 1 of the left tunnel ring and the precast bottom segment 2 of the right tunnel ring.

[0029] The top post-cast U-shaped beam 9 firmly connects the precast jacking segments 5 of the left tunnel ring and the precast jacking segments 6 of the right tunnel ring.

[0030] Please see Figure 2 The present invention proposes a tunnel ring support longitudinal beam system for the bottom of the above-mentioned subway underground station, including the above-mentioned left tunnel ring precast bottom segment 1, the above-mentioned right tunnel ring precast bottom segment 2, two above-mentioned bottom post-cast steel-concrete beams 7 and the above-mentioned bottom post-cast U-shaped beams 8.

[0031] The precast bottom segment 2 of the right tunnel ring is installed and fixed right next to the precast bottom segment 1 of the left tunnel ring.

[0032] A lower joint 11 is left between the precast bottom segment 1 of the left tunnel ring and the precast bottom segment 2 of the right tunnel ring. The lower joint 11 is filled with epoxy resin 112 for waterproofing.

[0033] A bottom left fixing block 101 protrudes upward from the right end of the precast bottom segment 1 of the left tunnel ring.

[0034] Bottom left anchor bar 103 is pre-embedded on the top of the bottom left fixing block 101 and the top of the pipe segment to its left.

[0035] A bottom right fixing block 201 protrudes upward from the left end of the precast bottom segment 2 of the right tunnel ring.

[0036] Bottom right anchor bar 203 is pre-embedded on the top of the bottom right fixing block 201 and the top of the segment to its right.

[0037] A bottom working hole 105 is opened in the bottom left fixing block 101 of the left tunnel ring precast bottom segment 1 and the bottom right fixing block 201 of the right tunnel ring precast bottom segment 2, and a bottom working hole reserved steel plate 107 is fixed in close contact with the inner wall of the bottom working hole 105.

[0038] Each bottom post-cast steel-concrete beam 7 includes an I-beam 72 located in the bottom working hole 105 and post-cast concrete 74 poured between the I-beam 72 and the reserved steel plate 107 of the bottom working hole.

[0039] The length of the I-beam 72 is the width of the 10 rings of the precast bottom segment 1 of the left tunnel ring (for ease of construction, the widths of the precast bottom segment 1, the precast bottom segment 2, the precast side segment 3, the precast side segment 4, the precast top segment 5, and the precast top segment 6 of the left tunnel ring are all the same).

[0040] The post-cast concrete 74 is used to cast and fix the two bottom post-cast steel-concrete beams 7 into the bottom working holes 105 of the precast bottom segments 1 of the left tunnel ring and the precast bottom segments 2 of the right tunnel ring.

[0041] The bottom post-cast U-shaped beam 8 includes a steel plate 81 encasing the bottom U-shaped beam, a steel cage 82 for the bottom U-shaped beam, and bottom post-cast concrete 83.

[0042] The bottom U-shaped beam is wrapped with steel plate 81 in the shape of an inverted U. Its left and right ends are respectively installed and fixed on the top wall of the left tunnel ring precast bottom segment 1 and the top wall of the right tunnel ring precast bottom segment 2. The middle protruding part is suspended above the bottom left fixing block 101 and the bottom right fixing block 201.

[0043] The bottom U-shaped beam is encased in a steel plate 81, which covers the bottom left anchor bar 103 and the bottom right anchor bar 203.

[0044] The bottom U-shaped beam is provided with bottom outer steel plate anchors 812 extending downward on the top wall of the outer steel plate 81.

[0045] The bottom U-shaped beam reinforcement cage 82 is installed between the bottom U-shaped beam outer steel plate 81 and the left tunnel ring precast bottom segment 1 and the right tunnel ring precast bottom segment 2.

[0046] The bottom left anchor bar 103, the bottom right anchor bar 203, and the bottom outer steel plate anchor nail 812 all extend into the bottom U-shaped beam reinforcement cage 82.

[0047] The bottom post-cast concrete 83 is poured between the bottom U-shaped beam outer steel plate 81 and the left tunnel ring precast bottom segment 1 and the right tunnel ring precast bottom segment 2. The bottom left anchor bar 103, the bottom right anchor bar 203 and the bottom outer steel plate anchor nail 812 all extend into and are poured and fixed into the bottom post-cast concrete 83.

[0048] With the combined action of the bottom left anchor bar 103, bottom right anchor bar 203, bottom outer steel plate anchor nail 812, bottom U-shaped beam reinforcement cage 82, and bottom post-cast concrete 83, the bottom post-cast U-shaped beam 8 is firmly cast and fixed to the upper part of the left tunnel ring precast bottom segment 1 and the right tunnel ring precast bottom segment 2. The left end of the bottom post-cast U-shaped beam 8 presses against the left side of the bottom left fixing block 101, and its right end presses against the right side of the bottom right fixing block 201, thereby firmly connecting the left tunnel ring precast bottom segment 1 and the right tunnel ring precast bottom segment 2. The two bottom post-cast steel-concrete beams 7 cast and fixed to the right end of the left tunnel ring precast bottom segment 1 and the left end of the right tunnel ring precast bottom segment 2 can greatly increase the strength and rigidity.

[0049] Please see Figure 3 The present invention proposes a tunnel ring support longitudinal beam system for the top of the above-mentioned subway underground station, including the above-mentioned left tunnel ring precast jacking segment 5, the above-mentioned right tunnel ring precast jacking segment 6, two above-mentioned top post-cast steel-concrete beams 9 and the above-mentioned top post-cast U-shaped beams 10.

[0050] The precast jacking segment 6 of the right tunnel ring is installed and fixed to the right side of the precast jacking segment 5 of the left tunnel ring.

[0051] An upper joint 51 is left between the precast jacking segment 5 of the left tunnel ring and the precast jacking segment 6 of the right tunnel ring. The upper joint 51 is filled with epoxy resin 512 for waterproofing.

[0052] A top left fixing block 501 protrudes downward from the right end of the precast jacking segment 5 of the left tunnel ring.

[0053] The bottom of the top left fixing block 501 and the bottom of the segment to its left are both pre-embedded with top left anchor bars 503.

[0054] A top right fixing block 601 protrudes downward from the left end of the precast jacking segment 6 of the right tunnel ring.

[0055] The bottom of the top right fixing block 601 and the bottom of the segment to its right are both pre-embedded with top right anchor bars 603.

[0056] A top working hole 505 is opened in the top left fixing block 501 of the left tunnel ring precast jacking segment 5 and the top right fixing block 601 of the right tunnel ring precast jacking segment 6, respectively, and a top working hole reserved steel plate 507 is fixed in close contact with the inner wall of the top working hole 505.

[0057] Each top post-cast steel-concrete beam 9 includes an I-beam 92 located in the top working hole 505 and post-cast concrete 94 poured between the I-beam 92 and the reserved steel plate 507 of the top working hole.

[0058] The length of the I-beam 92 is the width of the 10 rings of the precast jacking segment 5 of the left tunnel ring (for ease of construction, the widths of the precast bottom segment 1, the precast bottom segment 2, the precast side segment 3, the precast side segment 4, the precast jacking segment 5, and the precast jacking segment 6 of the left tunnel ring are all the same).

[0059] Two top post-cast steel-concrete beams 9 are cast into the top working holes 505 of the precast jacking segments 5 and 6 of the left and right tunnel rings using post-cast concrete 94.

[0060] The top post-cast U-shaped beam 10 includes a steel plate 1001 encasing the top U-shaped beam, a steel reinforcement cage 1002 for the top U-shaped beam, and top post-cast concrete 1003.

[0061] The top U-shaped beam is wrapped with a steel plate 1001 in the shape of a U. Its left and right ends are respectively installed and fixed on the bottom wall of the left tunnel ring precast jacking segment 5 and the bottom wall of the right tunnel ring precast jacking segment 6. The middle protruding part is suspended below the top left fixing block 501 and the top right fixing block 601.

[0062] The top U-shaped beam is encased in a steel plate 1001, which covers the top left anchor bar 503 and the top right anchor bar 603.

[0063] The bottom wall of the top U-shaped beam outer steel plate 1001 is provided with upward-extending top outer steel plate anchors 1012.

[0064] The top U-shaped beam reinforcement cage 1002 is installed between the top U-shaped beam outer steel plate 1001 and the left tunnel ring precast jacking segment 5 and the right tunnel ring precast jacking segment 6.

[0065] The top left anchor bar 503, the top right anchor bar 603, and the top outer steel plate anchor nail 1012 all extend into the top U-shaped beam reinforcement cage 1002.

[0066] The top post-cast concrete 1003 is poured between the steel plate 1001 encasing the top U-shaped beam and the precast jacking segments 5 and 6 of the left and right tunnel rings. The top left anchor bar 503, the top right anchor bar 603, and the top outer steel plate anchor nail 1012 all extend into and are poured and fixed inside the top post-cast concrete 1003.

[0067] With the combined action of the top left anchor bar 503, the top right anchor bar 603, the top outer steel plate anchor nail 1012, the top U-shaped beam reinforcement cage 1002, and the top post-cast concrete 1003, the top post-cast U-shaped beam 10 is firmly cast and fixed to the lower part of the left tunnel ring precast jacking segment 5 and the right tunnel ring precast jacking segment 6. The left end of the top post-cast U-shaped beam 10 presses against the left side of the top left fixing block 501, and its right end presses against the right side of the top right fixing block 601, thereby firmly connecting the left tunnel ring precast jacking segment 5 and the right tunnel ring precast jacking segment 6. The two top post-cast steel-concrete beams 9 cast and fixed to the right end of the left tunnel ring precast jacking segment 5 and the left end of the right tunnel ring precast jacking segment 6 can greatly increase the strength and rigidity.

[0068] Several permanent columns (not shown in the figure) are fixed between the bottom post-cast U-shaped beam 8 and the top post-cast U-shaped beam 9 to provide support.

[0069] The present invention also proposes a construction method for the tunnel ring support longitudinal beam system at the top of the above-mentioned subway cut-and-cover station, which includes the following steps: Step 1: Inject epoxy resin into the upper joint 51 between several left tunnel ring precast jacking segments 5 and several right tunnel ring precast jacking segments 6. The epoxy resin is a general building epoxy resin adhesive. When injecting epoxy resin, start from the middle ring of the tunnel and inject it ring by ring towards the first and last rings at both ends of the tunnel. After the epoxy resin injection is completed, check within 12 hours whether there are cavities in the upper joint 51 between several left tunnel ring precast jacking segments 5 and several right tunnel ring precast jacking segments 6. If there are cavities, inject epoxy resin again. Step 2: After forming the node waterproof unit with epoxy resin, insert I-beams 92 into the top working holes 505 of the precast jacking segments 5 and 6 of the left tunnel ring. The length of the I-beams 92 is 10 times the width of the precast jacking segments of the tunnel ring. They are inserted simultaneously from the first and last rings at both ends of the tunnel. After completion, check whether the total insertion length of the I-beams meets the standard. After the inspection, inject high-strength self-compacting concrete 94 to form the top post-cast steel-concrete beam 9. Step 3: Install and fix the top U-shaped beam steel cage 1002 and the top U-shaped beam outer steel plate 1001 to the lower part of the left tunnel ring precast jacking segment 5 and the right tunnel ring precast jacking segment 6; Step 4: High-strength self-compacting concrete is injected into the space formed by the steel plate 1001 encasing the top U-shaped beam, the precast jacking segment 5 of the left tunnel ring, and the precast jacking segment 6 of the right tunnel ring to form the top post-cast U-shaped beam 10; Step 5: When the strength of the top post-cast steel-concrete beam 9 and the top post-cast U-shaped beam 10 reaches the design requirements, the tunnel inter-ring support longitudinal beam system is formed.

[0070] The construction method for the tunnel ring support longitudinal beam system at the bottom of the aforementioned subway underground stations is similar to the above method and steps, only requiring corresponding adjustments based on the changes in the position of each component.

[0071] The present invention has the following beneficial effects: The top post-cast U-shaped beam 10 is firmly cast and fixed to the lower part of the left tunnel ring precast jacking segment 5 and the right tunnel ring precast jacking segment 6. The left end of the top post-cast U-shaped beam 10 presses against the left side of the top left fixing block 501, and its right end presses against the right side of the top right fixing block 601, thereby firmly connecting the left tunnel ring precast jacking segment 5 and the right tunnel ring precast jacking segment 6. The two top post-cast steel-concrete beams 9 cast and fixed to the right end of the left tunnel ring precast jacking segment 5 and the left end of the right tunnel ring precast jacking segment 6 can greatly increase the strength and rigidity.

Claims

1. A tunnel annular support longitudinal beam system, characterized in that, It includes several precast jacking segments of the left tunnel ring (5) fixed in parallel, several precast jacking segments of the right tunnel ring (6) fixed in parallel, several top post-cast steel-concrete beams (9) and top post-cast U-shaped beams (10). Several right tunnel ring precast jacking segments (6) are installed and fixed adjacent to the right side of several left tunnel ring precast jacking segments (5); A top left fixing block (501) protrudes downward from the right end of the precast jacking segment (5) of the left tunnel ring. A top right fixing block (601) protrudes downward from the left end of the precast jacking segment (6) of the right tunnel ring. Several top working holes (505) are respectively opened in the top left fixing block (501) and the top right fixing block (601); Several top post-cast steel-concrete beams (9) are cast into several top working holes (505); Each top post-cast steel-concrete beam (9) includes an I-beam (92) located in the top working hole (505) and post-cast concrete (94) poured between the I-beam (92) and the top working hole (505). The top post-cast U-shaped beam (10) includes a top U-shaped beam outer steel plate (1001) and a top post-cast concrete (1003); the left and right ends of the top U-shaped beam outer steel plate (1001) are respectively installed and fixed on the bottom wall of the left tunnel ring precast jacking segment (5) and the bottom wall of the right tunnel ring precast jacking segment (6), and the middle protruding part is suspended below the top left fixing block (501) and the top right fixing block (601); The top post-cast concrete (1003) was poured between the steel plate (1001) encased in the top U-shaped beam and the precast jacking segments (5) of the left tunnel ring and the precast jacking segments (6) of the right tunnel ring; The top post-cast U-shaped beam (10) is cast and formed at the bottom of the precast jacking segment (5) of the left tunnel ring and the precast jacking segment (6) of the right tunnel ring; The left end of the top post-cast U-shaped beam (10) presses against the left side of the top left fixing block (501), and its right end presses against the right side of the top right fixing block (601), thereby firmly connecting the left tunnel ring precast jacking segment (5) and the right tunnel ring precast jacking segment (6).

2. The tunnel inter-ring support longitudinal beam system according to claim 1, characterized in that, An upper joint (51) is left between the precast jacking segments (5) of the left tunnel ring and the precast jacking segments (6) of the right tunnel ring, and epoxy resin (512) is provided in the upper joint (51).

3. The tunnel inter-ring support longitudinal beam system according to claim 1, characterized in that, The bottom of the top left fixing block (501) and the bottom of the segment to its left are pre-embedded with top left anchor bars (503), and the bottom of the top right fixing block (601) and the bottom of the segment to its right are pre-embedded with top right anchor bars (603). The steel plate (1001) of the top U-shaped beam covers the top left anchor bars (503) and the top right anchor bars (603) inside it.

4. The tunnel inter-ring support longitudinal beam system according to claim 1, characterized in that, A pre-reserved steel plate (507) for the top working hole is fixedly installed on the inner wall of the top working hole (505), and the post-cast concrete (94) is poured between the I-beam (92) and the pre-reserved steel plate (507).

5. The tunnel inter-ring support longitudinal beam system according to claim 1, characterized in that, The widths of the precast jacking segments (5) in the left tunnel ring and the precast jacking segments (6) in the right tunnel ring are the same.

6. The tunnel inter-ring support longitudinal beam system according to claim 1, characterized in that, The top post-cast U-shaped beam (10) also includes a top U-shaped beam reinforcement cage (1002), which is installed between the top U-shaped beam outer steel plate (1001) and the left tunnel ring precast jacking segment (5) and the right tunnel ring precast jacking segment (6).

7. The tunnel inter-ring support longitudinal beam system according to claim 1, characterized in that, The bottom wall of the top U-shaped beam outer steel plate (1001) is provided with an upwardly extending top outer steel plate anchor (1012).

8. A construction method for the tunnel inter-ring support longitudinal beam system as described in claim 1, characterized in that, It includes the following steps: Step 1: Fix several left tunnel ring precast jacking segments (5) and several right tunnel ring precast jacking segments (6) side by side, and install and fix several right tunnel ring precast jacking segments (6) close to the right side of several left tunnel ring precast jacking segments (5). Step 2: Insert I-beams (92) into each top working hole (505) of the precast jacking segment (5) of the left tunnel ring and the precast jacking segment (6) of the right tunnel ring. The I-beams (92) are inserted simultaneously from the first and last rings at both ends of the tunnel. After completion, check whether the total insertion length of the I-beams meets the standard. After the inspection, inject high-strength self-compacting concrete (94) to form several top post-cast steel-concrete beams (9). Step 3: Install and fix the top U-shaped beam steel cage (1002) and the top U-shaped beam outer steel plate (1001) to the lower part of the left tunnel ring precast jacking segment (5) and the right tunnel ring precast jacking segment (6); Step 4: High-strength self-compacting concrete (1003) is injected into the space formed by the steel plate (1001) of the top U-shaped beam, the precast jacking segment (5) of the left tunnel ring, and the precast jacking segment (6) of the right tunnel ring to form the top post-cast U-shaped beam (10). Step 5: When the strength of the top post-cast steel-concrete beam (9) and the top post-cast U-shaped beam (10) reaches the design requirements, the tunnel inter-ring support longitudinal beam system is formed.

9. A construction method for the tunnel inter-ring support longitudinal beam system as described in claim 8, characterized in that, Between step 1 and step 2, the following steps are also included: injecting waterproofing agent into the upper joint (51) between several left tunnel ring precast jacking segments (5) and several right tunnel ring precast jacking segments (6). When injecting the waterproofing agent, it should start from the middle ring of the tunnel and inject it ring by ring towards the first and last rings at both ends of the tunnel. After the waterproofing agent is injected, check whether there is a cavity in the upper joint (51) between several left tunnel ring precast jacking segments (5) and several right tunnel ring precast jacking segments (6). If there is a cavity, inject the waterproofing agent a second time.

10. A construction method for the tunnel inter-ring support longitudinal beam system as described in claim 9, characterized in that, The aforementioned waterproofing agent is epoxy resin.

Images