Section steel concrete tunnel supporting structure

Abstract

The invention provides a steel reinforced concrete tunnel supporting structure, and belongs to the technical field of tunnel building structures. The problems that a profile steel frame in an existing composite lining of a tunnel is only used as a primary support structure, and the cooperative stress of a primary support and a secondary lining is poor are solved. The profile steel concrete tunnel supporting structure comprises a primary support, a secondary lining and a waterproof coating arranged between the primary support and the secondary lining, the secondary lining comprises profile steel frames and profile steel concrete, the profile steel frames can also serve as the primary support in the excavation period, and every two adjacent profile steel frames arranged in the longitudinal direction of a tunnel are connected through a connecting assembly. The construction progress of the tunnel is greatly accelerated, the bearing capacity of the profile steel frame is fully exerted, and the cooperative stress capacity of primary support and secondary lining is remarkably optimized.

Description

Technical Field

[0001] The invention belongs to the technical field of tunnel building structures and relates to a steel concrete tunnel supporting structure. Background Art

[0002] At present, tunnels generally use composite linings, and their support structures usually consist of primary support and secondary lining. The primary support needs to have a certain strength and rigidity to resist and inhibit the deformation of the surrounding rock. The primary support mainly consists of shotcrete, steel mesh and anchor rods. When the surrounding rock conditions around the tunnel are poor, the primary support needs to be equipped with a grid steel frame or a steel frame, and the secondary lining is a reinforced concrete structure. In order to ensure construction safety in the early stage of tunnel construction, the secondary lining is poured and reaches strength to share the load with the primary support.

[0003] Taking the two-bench method as an example, the tunnel construction process is as follows: excavation of the upper step → initial support of the upper step (anchor, net, spraying, erection of steel frame) → excavation of the lower step → initial support of the lower step → excavation of the invert → initial support of the invert → tying of the invert reinforcement → pouring of the invert lining → waterproof layer → tying of the arch wall reinforcement → pouring of the arch wall lining.

[0004] At present, conventional tunnel composite lining structures have the following disadvantages: 1. Tunnel construction processes are numerous, waterproof board paving requirements are high, secondary lining steel bar binding takes a long time, and construction progress is slow; 2. There are many construction processes from tunnel excavation to secondary lining pouring, and the time is long; 3. In order to avoid tunnel collapse and block falling, the initial support steel frame is set strong. In addition, considering the long-term durability of the initial support steel frame, the current secondary lining structure is calculated to bear a large load, and the bearing capacity of the initial support steel frame is not fully utilized; 4. A smooth waterproof board is set between the initial support and the secondary lining, which is not conducive to the coordinated force of the initial support and the secondary lining. Summary of the invention

[0005] The purpose of the present invention is to solve the above problems in the prior art and to propose a reinforced concrete tunnel support structure with coordinated force of initial support and secondary lining.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] The steel-concrete tunnel support structure includes initial support, secondary lining and a waterproof coating arranged between the initial support and the secondary lining. The secondary lining includes a steel frame and steel concrete. The steel frame can also serve as initial support during excavation. Two adjacent steel frames arranged along the longitudinal direction of the tunnel are connected by a connecting assembly.

[0008] The waterproof coating adopts cement-based penetrating crystalline waterproof coating, polyurethane waterproof coating, polyurea waterproof coating, etc. The construction method can be mechanical spraying or manual scraping, and the construction efficiency is high.

[0009] The steel frame can be made of I-beam or H-beam, welded steel and rolled steel. The steel frame should be made of Q235-BCD grade carbon structural steel and Q345-BCDE grade low alloy high strength structural steel.

[0010] During excavation, the steel frame can also serve as initial support, support the excavation surface, and control tunnel deformation; the smooth waterproof board is adjusted to a waterproof coating, which is quick to construct and has a simple process, and can greatly speed up the progress of tunnel construction; the initial support and secondary lining are well combined, which can significantly optimize the coordinated force-bearing capacity of the initial support and secondary lining.

[0011] In the above-mentioned steel-concrete tunnel support structure, the connection assembly includes a plurality of longitudinal main bars extending longitudinally along the tunnel, the plurality of longitudinal main bars are arranged in sequence along the circumferential direction of the steel frame, and the two ends of the longitudinal main bars are respectively connected to different steel frames.

[0012] The longitudinal main reinforcement should be made of Grade II or Grade III hot-rolled steel bars with a diameter greater than or equal to 16 mm, generally 16, 18, 20, 22, 25 mm, etc.

[0013] In the above-mentioned steel-concrete tunnel support structure, the longitudinal main reinforcement includes longitudinal main reinforcement located on the outside of the steel frame and longitudinal main reinforcement located on the inside of the steel frame. The two ends of the longitudinal main reinforcement located on the outside of the steel frame are connected to the flange plate on the outside of the steel frame, and the two ends of the longitudinal main reinforcement located on the inside of the steel frame are connected to the flange plate on the inside of the steel frame.

[0014] In the above-mentioned steel-concrete tunnel support structure, the longitudinal main reinforcement is located on the inner side of the steel frame, and the two ends of the longitudinal main reinforcement are connected to the flange plate on the inner side of the steel frame; the outer side of the steel frame is provided with a steel plate connected to the outer flange plate of the steel frame.

[0015] When the tunnel is located in an area with poor surrounding rock conditions or sensitive to deformation, in order to strengthen the rigidity of the initial support, not only the steel frame is used as the initial support, but also steel plates are set on the side of the steel frame close to the surrounding rock. The steel plates and the steel frame can be connected by welding.

[0016] The steel plate shall be hot-rolled and the thickness shall be greater than 6mm. The steel plate shall be divided into longitudinal and circumferential blocks along the curvature of the tunnel contour according to the construction needs, and then processed and transported to the site.

[0017] In the above-mentioned steel-concrete tunnel support structure, steel frames located in different circumferential directions are arranged alternately along the longitudinal direction of the tunnel.

[0018] In the above-mentioned steel-concrete tunnel support structure, the two ends of the longitudinal main reinforcement are connected to the flange plate of the steel frame through steel sleeves welded on the flange plate. The steel sleeves can be welded in advance or on-site to the flange plate of the steel frame. The longitudinal main reinforcement uses the steel sleeves to connect two adjacent steel frames into a whole, thereby improving the structural strength.

[0019] In the above-mentioned steel-concrete tunnel supporting structure, the steel casing extends in a direction perpendicular to the longitudinal direction of the tunnel, and both ends of the longitudinal main reinforcement have vertically arranged connecting sections, and the connecting sections are inserted into the steel casings arranged correspondingly thereto.

[0020] In the above-mentioned steel-concrete tunnel support structure, the initial support includes anchor rods, steel mesh and sprayed concrete.

[0021] In the above steel-concrete tunnel support structure, the initial support includes anchor rods and fiber sprayed concrete. Fiber sprayed concrete is to add fiber materials to sprayed concrete, and the fiber materials are mainly carbon fiber, polypropylene fiber and steel fiber.

[0022] In the above-mentioned steel concrete tunnel support structure, fiber materials are added to the steel concrete, and the fiber materials include carbon fiber, polypropylene fiber and steel fiber. The strength grade of the steel concrete is not less than C30, the maximum aggregate diameter of the steel concrete is not more than 25mm, and the thickness of the protective layer formed by the steel concrete located inside the steel frame is not less than 100mm.

[0023] Taking the two-step method as an example, the tunnel construction process using the steel-concrete tunnel support structure is as follows: excavation of the upper step → initial support (anchor, net, spray) of the upper step, brushing of waterproof coating and erection of steel frame → excavation of the lower step → initial support of the lower step, brushing of waterproof coating and erection of steel frame → excavation of the invert → initial support of the invert and erection of steel frame → pouring of invert steel-concrete → pouring of arch wall steel-concrete.

[0024] Compared with the conventional tunnel composite lining structure, the secondary lining is adjusted from reinforced concrete to steel concrete, eliminating the cumbersome steel bar binding process, and the waterproof layer is adjusted from smooth waterproof board to waterproof coating. The construction is fast and the process is simple, which can greatly speed up the tunnel construction progress; the steel frame also serves as the initial support structure during excavation, and is cast into the secondary lining after excavation, giving full play to the bearing capacity of the steel frame; because it is a waterproof coating, the initial support and secondary lining are well combined, which can significantly optimize the coordinated force-bearing capacity of the initial support and secondary lining. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a cross-sectional schematic diagram of the steel concrete tunnel support structure.

[0026] Figure 2 The first embodiment provides Figure 1 Schematic diagram of the cross section at AA in the middle.

[0027] Figure 3 It is a structural schematic diagram of the connection between the steel frame and the longitudinal main reinforcement provided in Example 1.

[0028] Figure 4 It is a cross-sectional schematic diagram of the connection between the steel frame and the longitudinal main reinforcement provided in the first embodiment.

[0029] Figure 5 It is a schematic diagram of the structure of the longitudinal main reinforcement provided in the first embodiment.

[0030] Figure 6 The second embodiment provides Figure 1 Schematic diagram of the cross section at AA in the middle.

[0031] Figure 7 It is a schematic diagram of the structure of the connection between the steel frame and the longitudinal main reinforcement provided in the second embodiment.

[0032] Figure 8 It is a cross-sectional schematic diagram of the connection between the steel frame and the longitudinal main reinforcement provided in the second embodiment.

[0033] Fig. 9 It is a schematic diagram of the structure of the longitudinal main reinforcement provided in the second embodiment.

[0034] Fig.10 The third embodiment provides Figure 1 Schematic diagram of the cross section at AA in the middle.

[0035] In the figure, 1. anchor rod; 2. steel mesh; 3. sprayed concrete; 4. waterproof coating; 5. steel frame; 6. steel casing; 7. longitudinal main reinforcement; 71. connecting section; 8. steel plate. DETAILED DESCRIPTION

[0036] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0037] Embodiment 1

[0038] like Figure 1 The steel-concrete tunnel support structure shown includes initial support, secondary lining and a waterproof coating 4 arranged between the initial support and the secondary lining. The initial support in this embodiment includes anchor rods 1, steel mesh 2 and sprayed concrete 3, and the secondary lining includes steel frames 5 and steel concrete. The steel frames 5 can also serve as initial support during excavation. Two adjacent steel frames 5 arranged along the longitudinal direction of the tunnel are connected by a connecting assembly.

[0039] The waterproof coating 4 adopts cement-based penetrating crystallization waterproof coating, polyurethane waterproof coating, polyurea waterproof coating, etc. The construction method adopts mechanical spraying method, and can also adopt manual scraping method, and the construction efficiency is high.

[0040] The steel frame 5 can be made of I-beam or H-beam, and can be made of welded steel and rolled steel. The steel frame 5 is preferably made of Q235-BCD grade carbon structural steel and Q345-BCDE grade low alloy high strength structural steel.

[0041] The steel frame 5 can also serve as initial support during excavation, support the excavation surface, and control tunnel deformation; the smooth waterproof board is adjusted to a waterproof coating 4, which is quick to construct and simple in process, and can greatly speed up the progress of tunnel construction; the initial support and secondary lining are well combined, which can significantly optimize the coordinated force bearing capacity of the initial support and the secondary lining.

[0042] like Figure 2-4 As shown, the connection assembly includes a plurality of longitudinal main bars 7 extending in the longitudinal direction of the tunnel, and the plurality of longitudinal main bars 7 are sequentially arranged along the circumferential direction of the steel frame 5, preferably evenly arranged, and the two ends of the longitudinal main bars 7 are respectively connected to different steel frames 5. The longitudinal main bars 7 are made of grade II or grade III hot-rolled steel bars, and the diameter of the steel bars is greater than or equal to 16 mm, such as 16, 18, 20, 22, 25 mm, etc.

[0043] like Figure 2 and Figure 4 As shown, the longitudinal main reinforcement 7 includes the longitudinal main reinforcement 7 located on the outside of the steel frame 5 and the longitudinal main reinforcement 7 located on the inside of the steel frame 5. The two ends of the longitudinal main reinforcement 7 located on the outside of the steel frame 5 are connected to the flange plate on the outside of the steel frame 5, and the two ends of the longitudinal main reinforcement 7 located on the inside of the steel frame 5 are connected to the flange plate on the inside of the steel frame 5.

[0044] like Figure 5 As shown, the longitudinal main reinforcement 7 is in a straight line shape, and its two ends are respectively welded to the flange plate of the steel frame 5. Figure 3 As shown, the steel frames 5 located in different circumferential directions are arranged alternately along the longitudinal direction of the tunnel.

[0045] In this embodiment, fiber materials are added to the steel concrete, and the fiber materials include carbon fiber, polypropylene fiber and steel fiber. The strength grade of the steel concrete is not less than C30, the maximum aggregate diameter of the steel concrete is not more than 25mm, and the thickness of the protective layer formed by the steel concrete located inside the steel frame 5 is not less than 100mm.

[0046] Taking the two-step method as an example, the tunnel construction process using the steel concrete tunnel support structure is as follows: excavation of the upper step → initial support of the upper step (anchor, net, spray), brushing of waterproof coating 4 and erection of steel frame 5 → excavation of the lower step → initial support of the lower step, brushing of waterproof coating 4 and erection of steel frame 5 → excavation of the invert → initial support of the invert and erection of steel frame 5 → pouring of invert steel concrete → pouring of arch wall steel concrete.

[0047] Embodiment 2

[0048] The structural principle of this embodiment is basically the same as that of the first embodiment, except that Figure 6-8 As shown, both ends of the longitudinal main reinforcement 7 are connected to the flange plate of the steel frame 5 through the steel sleeve 6 welded on the flange plate. The steel sleeve 6 is welded in advance or on-site to the flange plate of the steel frame 5. The longitudinal main reinforcement 7 uses the steel sleeve 6 to connect two adjacent steel frames 5 into a whole, thereby improving the structural strength.

[0049] Specifically, Figure 7 As shown, the steel casing 6 extends perpendicular to the longitudinal direction of the tunnel. Fig. 9 As shown, both ends of the longitudinal main reinforcement 7 have vertically arranged connecting sections 71, and the connecting sections 71 are inserted into the steel casing 6 correspondingly arranged thereto.

[0050] Embodiment 3

[0051] The structural principle of this embodiment is basically the same as that of the second embodiment, except that Fig.10 As shown, the longitudinal main reinforcement 7 is located on the inner side of the steel frame 5, and both ends of the longitudinal main reinforcement 7 are connected to the flange plate on the inner side of the steel frame 5. The outer side of the steel frame 5 is provided with a steel plate 8 connected to the outer flange plate of the steel frame 5.

[0052] When the tunnel is in an area with poor surrounding rock conditions or sensitive to deformation, in order to strengthen the rigidity of the initial support, not only the steel frame 5 is used as the initial support, but also a steel plate 8 is set on the side of the steel frame 5 close to the surrounding rock, and the steel plate 8 and the steel frame 5 can be connected by welding.

[0053] The steel plate 8 is a hot-rolled steel plate 8 with a thickness greater than 6 mm. The steel plate 8 is divided into blocks along the curvature of the tunnel contour by the manufacturer according to construction needs, and then processed and transported to the site.

[0054] Embodiment 4

[0055] The structural principle of this embodiment is basically the same as that of the first embodiment, except that the initial support includes an anchor rod 1 and fiber sprayed concrete 3. The fiber sprayed concrete 3 is obtained by adding fiber materials to the sprayed concrete 3. The fiber materials are mainly carbon fiber, polypropylene fiber, steel fiber, etc.

[0056] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A steel-concrete tunnel support structure, characterized in that: The invention comprises an initial support, a secondary lining and a waterproof coating (4) arranged between the initial support and the secondary lining. The secondary lining comprises a steel frame (5) and steel concrete. The steel frame (5) can also serve as the initial support during excavation. Two adjacent steel frames (5) arranged along the longitudinal direction of the tunnel are connected by a connecting assembly.

2. The reinforced concrete tunnel support structure according to claim 1 is characterized in that: The connection assembly comprises a plurality of longitudinal main bars (7) extending in the longitudinal direction of the tunnel, wherein the plurality of longitudinal main bars (7) are arranged in sequence along the circumferential direction of the steel frame (5), and the two ends of the longitudinal main bars (7) are respectively connected to different steel frames (5).

3. The reinforced concrete tunnel support structure according to claim 2 is characterized in that: The longitudinal main reinforcement (7) comprises a longitudinal main reinforcement (7) located outside the profile steel frame (5) and a longitudinal main reinforcement (7) located inside the profile steel frame (5), wherein both ends of the longitudinal main reinforcement (7) located outside the profile steel frame (5) are connected to the flange plate outside the profile steel frame (5), and both ends of the longitudinal main reinforcement (7) located inside the profile steel frame (5) are connected to the flange plate inside the profile steel frame (5).

4. The reinforced concrete tunnel support structure according to claim 2 is characterized in that: The longitudinal main reinforcement (7) is located on the inner side of the profile steel frame (5), and the two ends of the longitudinal main reinforcement (7) are connected to the flange plate on the inner side of the profile steel frame (5); the outer side of the profile steel frame (5) is provided with a steel plate (8) connected to the outer flange plate of the profile steel frame (5).

5. The reinforced concrete tunnel support structure according to claim 2, 3 or 4, characterized in that: The steel frames (5) located in different circumferential directions are arranged in a staggered manner along the longitudinal direction of the tunnel.

6. The reinforced concrete tunnel support structure according to claim 2, 3 or 4, characterized in that: The two ends of the longitudinal main reinforcement (7) are connected to the flange plate of the steel frame (5) through steel sleeves (6) welded on the flange plate.

7. The reinforced concrete tunnel support structure according to claim 6 is characterized in that: The steel casing (6) extends in a direction perpendicular to the longitudinal direction of the tunnel. Both ends of the longitudinal main reinforcement (7) are provided with vertically arranged connecting sections (71), and the connecting sections (71) are inserted into the correspondingly arranged steel casing (6).

8. The reinforced concrete tunnel support structure according to claim 1 is characterized in that: The initial support comprises anchor rods (1), a steel mesh (2) and shotcrete (3).

9. The reinforced concrete tunnel support structure according to claim 1, characterized in that: The initial support comprises an anchor rod (1) and fiber shotcrete (3).

10. The reinforced concrete tunnel support structure according to claim 1, characterized in that: Fiber material is added into the steel concrete.

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