Shield tunnel outwards-protruding type tunnel portal ring beam construction method and tunnel portal ring beam structure

Abstract

According to the shield tunnel outwards-protruding type tunnel portal ring beam construction method and the tunnel portal ring beam structure, a tunnel portal segment is arranged to protrude out of a tunnel portal of a station main body structure, a segment steel plate and a tunnel portal steel ring are welded into a whole through an annular blocking steel plate, and an annular gap is formed between the tunnel portal segment and the tunnel portal; and then grouting filling is carried out on the annular gap through a grouting steel pipe, tunnel portal ring beam construction is carried out after filling is completed, and the tunnel portal ring beam is arranged to protrude out of the tunnel portal. According to the method and structure, the outwards-protruding type tunnel portal ring beam is adopted, compared with a traditional lining type ring beam, the construction quality is better, safer and more reliable, the influence of the length, stretching out of the portal end, of an original tunnel portal segment is avoided, the original segment in a tunnel does not need to be damaged, water gushing and sand gushing accidents caused by segment cutting and dismantling are avoided, the construction risk is reduced, and the construction efficiency is improved. The construction space is large, and meanwhile, it can be guaranteed that the annular gap behind the tunnel segment wall and poured tunnel portal ring beam concrete are densely filled through grouting.

Description

Technical Field

[0001] The invention relates to the technical field of shield tunnel construction, and in particular to a shield tunnel convex tunnel portal ring beam construction method and a tunnel portal ring beam structure. Background Art

[0002] The portal ring beam is a circular concrete structure used in tunnel engineering. It is located at the tunnel entrance and surrounds the front end of the tunnel lining. It is an important part connecting the internal lining of the tunnel and the external structure of the entrance, playing a role of reinforcement and transition.

[0003] At present, when constructing the portal ring beam, the portal ring beam is usually placed in the tunnel to form an inner-lined portal ring beam. The portal segments need to be dismantled or cut according to their length and the structural dimensions of the portal ring beam. This method can easily cause water and sand gushing into the building gap between the shield tunnel and the station, causing a great impact on the surrounding environment. Summary of the invention

[0004] In order to solve the above-mentioned technical problems, the present invention provides a shield tunnel convex portal ring beam construction method and a portal ring beam structure. By using the convex portal ring beam, there is no need to dismantle or cut the tunnel opening segments, thereby avoiding water and sand gushing accidents caused by cutting or dismantling the segments, thereby reducing construction risks.

[0005] In order to achieve the above technical purpose, the present invention adopts a scheme as follows: a method for constructing a shield tunnel convex portal ring beam is provided, comprising the following steps:

[0006] 1) The opening segment protrudes from the main structure of the station. The back of the opening segment is provided with a segment steel plate in an annular direction. The opening of the main structure of the station is provided with an opening steel ring in an annular direction. First, the opening sealing device of the main structure of the station is removed. After the opening sealing device is removed, the segment steel plate and the opening steel ring are welded into a whole through the annular blocking steel plate, and an annular gap is formed between the opening segment and the opening;

[0007] 2) The plugging steel plate is provided with an opening connected to the annular void, a grouting steel pipe is inserted into the opening, and then grouting is injected into the annular void through the grouting steel pipe to fill the annular void;

[0008] 3) Bolt holes are provided on the tunnel segment, and long bolts are fixed on the bolt holes and extended into the construction range of the tunnel ring beam;

[0009] 4) Carry out roughening and planting of reinforcement on the main structure of the station within the construction scope of the tunnel ring beam and the end side walls of the tunnel segment, and install water-swelling waterproofing strips on the main structure of the station within the construction scope of the tunnel ring beam and the end side walls of the tunnel segment;

[0010] 5) Tie the steel frame of the tunnel gate ring beam within the construction range of the tunnel gate ring beam. During tying, grouting steel pipes need to be set on the steel frame of the tunnel gate ring beam;

[0011] 6) Set up formwork and support on the steel frame of the portal ring beam for reinforcement, then pour the concrete of the portal ring beam through the pouring window on the formwork, and remove the formwork and support after pouring;

[0012] 7) After the formwork and support are removed, the concrete of the tunnel gate ring beam is grouted through the grouting steel pipe set on the steel frame of the tunnel gate ring beam to ensure that the concrete of the tunnel gate ring beam is dense.

[0013] As a further improvement of the method of the present invention, in step 1), the hole segment protrudes 400 to 600 mm from the hole of the station main structure; removing the hole sealing device means removing the annular curtain rubber plate, the annular pressure plate and the folding plate.

[0014] As a further improvement of the method of the present invention, in step 2), a plurality of openings are provided, and the plurality of openings are circumferentially arranged at intervals of 30°; and the grouting is the injection of cement slurry or the injection of a double liquid slurry consisting of cement slurry and water glass.

[0015] As a further improvement of the method described in the present invention, in step 3), the bolt hole extends in an arc shape from the inner wall of the tunnel segment to the end side wall of the tunnel segment, and the long bolt includes a straight section and an arc section. The straight section extends into the construction range of the tunnel ring beam, and the arc section is fixed to the bolt hole of the tunnel segment by a nut and a gasket.

[0016] The present invention also provides a shield tunnel outward protruding portal ring beam structure, comprising a station main structure, a portal pipe segment and a portal ring beam, the portal pipe segment is protruding out of the portal of the station main structure, a pipe segment steel plate is circumferentially arranged on the back of the portal pipe segment, a portal steel ring is circumferentially arranged at the portal of the station main structure, a sealing steel plate is welded between the pipe segment steel plate and the portal steel ring, so that an annular gap is formed between the portal pipe segment and the portal, the annular gap is filled with slurry, and the end side walls of the portal ring beam are arranged on the station main structure, the portal pipe segment and the sealing steel plate.

[0017] As a further improvement of the structure described in the present invention, the opening pipe segment protrudes out of the opening of the station main structure by 400 to 600 mm.

[0018] As a further improvement of the structure described in the present invention, the sealing steel plate is provided with a plurality of openings connected to the annular gap, and the plurality of openings are arranged annularly at intervals of 30°. Grouting steel pipes are inserted into the openings, and liquid slurry is injected into the annular gap through the grouting steel pipes to fill the annular gap. The liquid slurry is cement slurry or a double liquid slurry consisting of cement slurry and water glass.

[0019] As a further improvement of the structure described in the present invention, a water-swellable waterproofing strip is arranged between the outer side wall of the station main structure and the tunnel gate ring beam; a water-swellable waterproofing strip is arranged between the end side wall of the tunnel opening segment and the end side wall of the tunnel gate ring beam.

[0020] As a further improvement of the structure of the present invention, it also includes long bolts. Bolt holes are provided on the tunnel pipe segments. The long bolts are fixed on the bolt holes and extend into the tunnel gate ring beam.

[0021] As a further improvement of the structure described in the present invention, the bolt hole extends in an arc shape from the inner wall of the tunnel segment to the end side wall of the tunnel segment, and the long bolt includes a straight section and an arc section. The straight section extends into the tunnel gate ring beam, and the arc section is fixed to the bolt hole of the tunnel segment by a nut and a gasket.

[0022] The beneficial effects of the present invention are as follows: the method and structure described in the present invention adopt an outward convex portal ring beam, which has better construction quality than the traditional inner lining ring beam, is safer and more reliable, will not be affected by the length of the original tunnel portal segment extending out of the portal end, does not need to destroy the original segment in the tunnel, avoids water and sand gushing accidents caused by cutting and removing the segment, reduces construction risks, and has a large construction space. At the same time, grouting can ensure that the annular gap behind the tunnel segment wall and the poured portal ring beam concrete are densely filled to prevent water seepage. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the tunnel gate ring beam structure of the present invention;

[0024] Marking description: station main structure 1, opening 11, opening steel ring 12, opening segment 2, segment steel plate 21, portal ring beam 3, sealing steel plate 4, annular gap 5, grouting steel pipe 6, water-swelling waterstop strip 7, long bolt 8. DETAILED DESCRIPTION

[0025] The present invention will be further described below in conjunction with specific embodiments and accompanying drawings.

[0026] A shield tunnel convex portal ring beam construction method comprises the following steps:

[0027] 1) The length of the hole segment 2 protruding from the hole 11 of the station main structure 1 is 400-600 mm. In this embodiment, the length of the hole segment 2 protruding from the hole 11 of the station main structure 1 is 500 mm. A segment steel plate 21 is circumferentially arranged on the back of the hole segment 2, and a hole steel ring 12 is circumferentially arranged at the hole 11 of the station main structure 1. During construction, the hole sealing device of the station main structure 1 is first removed. The hole sealing device includes an annular curtain rubber plate, an annular pressure plate and a folding plate. After the hole sealing device is removed, the segment steel plate 21 and the hole steel ring 12 are welded into a whole through the annular sealing steel plate 4, and an annular gap 5 is formed between the hole segment 2 and the hole 11.

[0028] 2) The plugging steel plate 4 is provided with a plurality of openings connected to the annular gap 5, and the plurality of openings are arranged annularly at intervals of 30°. A grouting steel pipe 6 is inserted into the opening, and then grouting is injected into the annular gap 5 through the grouting steel pipe 6 to fill the annular gap 5. The grouting is to inject cement slurry or a double slurry composed of cement slurry and water glass. This step realizes the filling of the annular gap 5 to prevent water seepage between the hole segment 2 and the hole 11.

[0029] 3) Bolt holes are provided on the tunnel segment 2. The bolt holes are arc-shaped and penetrate from the inner side wall of the tunnel segment 2 to the end side wall of the tunnel segment 2. Long bolts 8 are fixed on the bolt holes and are extended into the construction range of the tunnel gate ring beam 3. The long bolts 8 include straight sections and arc sections. The straight sections extend into the construction range of the tunnel gate ring beam 3. The arc sections are fixed on the bolt holes of the tunnel segment 2 through nuts and washers. The long bolts 8 are used to ensure the tightness and integrity of the connection between the tunnel segment 2 and the cast tunnel gate ring beam 3 structure.

[0030] 4) Roughen and plant reinforcement on the station main structure 1 within the construction range of the tunnel ring beam 3 and the end side wall of the tunnel segment 2. The anchor depth of the reinforcement is not less than 420mm, and the first-class reinforcement glue is used to fill the reinforcement hole. After the roughening and reinforcement are completed, the water-swelling waterproofing strip 7 is installed on the station main structure 1 within the construction range of the tunnel ring beam 3 and the end side wall of the tunnel segment 2;

[0031] 5) The portal ring beam reinforcement skeleton is tied within the construction range of the portal ring beam 3. During the tying process, grouting steel pipes are arranged in a circumferential direction at intervals of 30° on the portal ring beam reinforcement skeleton. The grouting steel pipes are mainly used for grouting after the concrete pouring of the portal ring beam is completed to ensure that the concrete is dense.

[0032] 6) Combined steel formwork and support are set on the steel skeleton of the portal ring beam for reinforcement to prevent the combined steel formwork from exploding, deflecting or leaking. A pouring window is set at a certain distance on the combined steel formwork, and the concrete of the portal ring beam is poured through the pouring window on the formwork. During the pouring process, the concrete is poured symmetrically in layers from the height direction of the ring beam. At the same time, a vibrator is used to compact the concrete evenly. The pouring height of each layer of concrete is 30cm, and the height difference on both sides should not be greater than 0.5m. The pouring time of the upper and lower layers of concrete should not exceed the initial setting time of the concrete. After the concrete is poured, it needs to be cured. When the concrete strength reaches 2.5MPa and there is no edge cracking when removing the formwork, the formwork and support are removed. The removal order is from top to bottom.

[0033] 7) After the formwork and support are removed, the concrete of the tunnel gate ring beam is grouted through the grouting steel pipe set on the steel frame of the tunnel gate ring beam to ensure that the concrete of the tunnel gate ring beam is dense.

[0034] The structure of the tunnel gate ring beam 3 formed by the above construction method is as follows Figure 1 As shown. A shield tunnel convex portal ring beam 3 structure includes a station main structure 1, a portal segment 2 and a portal ring beam 3. The length of the portal segment 2 protruding from the opening 11 of the station main structure 1 is set to 400-600 mm. In this embodiment, the length of the portal segment 2 protruding from the opening 11 of the station main structure 1 is set to 500 mm. A segment steel plate 21 is circumferentially arranged on the back of the portal segment 2, and a portal steel ring 12 is circumferentially arranged at the opening 11 of the station main structure 1. A sealing steel plate 4 is welded between the segment steel plate 21 and the portal steel ring 12, so that an annular gap 5 is formed between the portal segment 2 and the opening 11. The annular gap 5 is filled with slurry, which is cement slurry or double slurry composed of cement slurry and water glass. The annular gap 5 is filled with slurry to prevent water seepage between the portal segment 2 and the opening 11. The end side walls of the tunnel gate ring beam 3 are arranged on the station main structure 1, the tunnel opening pipe segment 2 and the blocking steel plate 4, so that the tunnel gate ring beam 3 is protruded out of the tunnel opening 11.

[0035] In order to facilitate grouting filling, the sealing steel plate 4 is provided with a plurality of openings connected to the annular gap 5. The plurality of openings are arranged annularly at intervals of 30°. A grouting steel pipe 6 is inserted into the opening, and liquid slurry is injected into the annular gap 5 through the grouting steel pipe 6 for filling.

[0036] Water-swellable waterproofing strips 7 are respectively arranged between the outer side wall of the station main structure 1 and the tunnel gate ring beam 3, and between the end side wall of the tunnel opening segment 2 and the end side wall of the tunnel gate ring beam 3, so as to prevent water seepage in the tunnel gate ring beam 3.

[0037] The tunnel segment 2 is provided with a bolt hole, which extends from the inner side wall of the tunnel segment 2 to the end side wall of the tunnel segment 2 in an arc shape, and a long bolt 8 is fixed on the bolt hole and inserted into the tunnel gate ring beam 3. The long bolt 8 includes a straight section and an arc section, and the straight section extends into the tunnel gate ring beam 3. The arc section is fixed to the bolt hole of the tunnel segment 2 through a nut and a gasket. The long bolt 8 is used to ensure the tightness and integrity of the connection between the tunnel segment 2 and the tunnel gate ring beam 3.

[0038] A tunnel gate ring beam reinforcement skeleton is arranged in the tunnel gate ring beam 3, and grouting steel pipes are circumferentially arranged on the tunnel gate ring beam reinforcement skeleton at 30° intervals. Grouting is injected into the tunnel gate ring beam 3 through the grouting steel pipes to ensure that the tunnel gate ring beam 3 is dense.

[0039] The above embodiments are only used to illustrate the present invention. Any person with ordinary knowledge in the technical field can make equivalent embodiments by making partial changes or modifications to the technical contents disclosed in the present invention without departing from the scope of the technical features of the present invention, and they still fall within the scope of the technical features of the present invention without departing from the technical features of the present invention.

Claims

1. A method for constructing a shield tunnel external convex portal ring beam, characterized in that The following steps are involved: 1) The opening segment protrudes from the main structure of the station. The back of the opening segment is provided with a segment steel plate in an annular direction. The opening of the main structure of the station is provided with an opening steel ring in an annular direction. First, the opening sealing device of the main structure of the station is removed. After the opening sealing device is removed, the segment steel plate and the opening steel ring are welded into a whole through the annular blocking steel plate, and an annular gap is formed between the opening segment and the opening; 2) The plugging steel plate is provided with an opening connected to the annular void, a grouting steel pipe is inserted into the opening, and then grouting is injected into the annular void through the grouting steel pipe to fill the annular void; 3) Bolt holes are provided on the tunnel segment, and long bolts are fixed on the bolt holes and extended into the construction range of the tunnel ring beam; 4) Carry out roughening and planting of reinforcement on the main structure of the station within the construction scope of the tunnel ring beam and the end side walls of the tunnel segment, and install water-swelling waterproofing strips on the main structure of the station within the construction scope of the tunnel ring beam and the end side walls of the tunnel segment; 5) Tie the steel frame of the tunnel gate ring beam within the construction range of the tunnel gate ring beam. During tying, grouting steel pipes need to be set on the steel frame of the tunnel gate ring beam; 6) Set up formwork and support on the steel frame of the portal ring beam for reinforcement, then pour the concrete of the portal ring beam through the pouring window on the formwork, and remove the formwork and support after pouring; 7) After the formwork and support are removed, the concrete of the tunnel gate ring beam is grouted through the grouting steel pipe set on the steel frame of the tunnel gate ring beam to ensure that the concrete of the tunnel gate ring beam is dense.

2. A shield tunnel convex portal ring beam construction method according to claim 1, characterized in that: In step 1), the opening segment protrudes out of the opening of the station main structure by 400 to 600 mm; removing the opening sealing device refers to removing the annular curtain rubber plate, the annular pressure plate and the folding plate.

3. The method for constructing a shield tunnel external convex portal ring beam according to claim 1, characterized in that: In step 2), a plurality of openings are provided, and the plurality of openings are arranged circumferentially at intervals of 30°; and the grouting is performed by injecting cement slurry or injecting a double liquid slurry consisting of cement slurry and water glass.

4. A shield tunnel convex portal ring beam construction method according to claim 1, characterized in that: In step 3), the bolt hole extends in an arc shape from the inner wall of the tunnel segment to the end side wall of the tunnel segment. The long bolt includes a straight section and an arc section. The straight section extends into the construction range of the tunnel ring beam, and the arc section is fixed to the bolt hole of the tunnel segment by a nut and a gasket.

5. A shield tunnel convex portal ring beam structure, comprising a station main structure, a portal segment and a portal ring beam, characterized in that: The opening segment protrudes out of the opening of the station main structure, a segment steel plate is circumferentially arranged on the back of the segment, an opening steel ring is circumferentially arranged at the opening of the station main structure, a sealing steel plate is welded between the segment steel plate and the opening steel ring, so that an annular gap is formed between the segment and the opening, and the annular gap is filled with slurry, and the end side walls of the portal ring beam are arranged on the station main structure, the segment and the sealing steel plate.

6. The shield tunnel outward convex portal ring beam structure according to claim 5, characterized in that: The opening pipe segment protrudes out of the opening of the station main structure by 400 to 600 mm.

7. The shield tunnel outward convex portal ring beam structure according to claim 5, characterized in that: The blocking steel plate is provided with a plurality of openings connected to the annular gap, and the plurality of openings are arranged annularly at intervals of 30°. Grouting steel pipes are inserted into the openings, and liquid slurry is injected into the annular gap through the grouting steel pipes to fill the annular gap. The liquid slurry is cement slurry or a double liquid slurry consisting of cement slurry and water glass.

8. The shield tunnel outward convex portal ring beam structure according to claim 5, characterized in that: A water-swellable waterproofing strip is arranged between the main structure of the station and the outer side wall of the tunnel gate ring beam; a water-swellable waterproofing strip is arranged between the end side wall of the tunnel opening segment and the end side wall of the tunnel gate ring beam.

9. The shield tunnel outward convex portal ring beam structure according to claim 5, characterized in that: It also includes a long bolt. The hole segment is provided with a bolt hole. The long bolt is fixed on the bolt hole and extends into the hole ring beam.

10. The shield tunnel outward convex portal ring beam structure according to claim 9, characterized in that: The bolt hole extends in an arc shape from the inner side wall of the tunnel segment to the end side wall of the tunnel segment. The long bolt includes a straight section and an arc section. The straight section extends into the tunnel gate ring beam, and the arc section is fixed to the bolt hole of the tunnel segment by a nut and a gasket.

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