Large-section tunnel second lining anti-collapse structure

Abstract

The utility model provides an anti-collapse structure for a second lining of a large-section tunnel. A grid arch frame comprises a plurality of grid main ribs matched with the grid arch frame in shape. The second concrete lining is located on the inner side of the grid arch frame, a plurality of stirrups are arranged in the second concrete lining, and the stirrups are fixedly connected with longitudinal bars in the second concrete lining; one end of the connecting piece extends into the stirrup and is fixedly connected with a secondary lining main rib of the concrete secondary lining and the stirrup; the other end of the connecting piece extends into the grid arch frame; the fixing pieces are fixedly connected with the grid main ribs and are connected with the connecting pieces after being bent in an L shape. The stirrups are additionally arranged in the construction process of the internal concrete secondary lining and are used for connecting and fixing the connecting pieces, so that the grating arch frame and the internal steel bars of the concrete secondary lining are fixed, the secondary lining structure cannot collapse, and great safety guarantee is provided for field personnel and property.

Description

Technical Field

[0001] This utility model belongs to the field of tunnel secondary lining technology, specifically relating to a collapse-proof structure for the secondary lining of large-section tunnels. Background Technology

[0002] After the initial tunnel support (such as shotcrete, anchor bolts, steel frames, etc.) is completed, secondary lining construction is required to improve the overall stability and waterproofing performance of the tunnel. Due to factors such as large or oversized tunnel cross-sections, improper construction techniques, and poor management, secondary lining structure collapses may occur, causing casualties and property damage. Therefore, preventing secondary lining structure collapse is crucial during construction. Currently, rebar installation is commonly used to fix and connect the initial support and secondary lining structure in order to prevent secondary lining collapse. However, rebar installation requires more procedures and materials, making the construction process relatively complicated and easily affected by construction conditions and techniques, making it difficult to achieve ideal results. Furthermore, according to the applicant's understanding, most current methods for preventing secondary lining collapse involve strengthening the concrete to increase its load-bearing capacity, which undoubtedly increases costs.

[0003] Therefore, there is a need to provide an improved technical solution that addresses the shortcomings of the existing technology. Utility Model Content

[0004] The purpose of this utility model is to overcome the shortcomings of the prior art and to provide a large-section tunnel secondary lining anti-collapse structure.

[0005] To achieve the above objectives, this utility model provides the following technical solution:

[0006] A collapse-resistant secondary lining structure for large-section tunnels includes:

[0007] A grid arch frame, the grid arch frame comprising multiple grid main reinforcement bars adapted to its shape;

[0008] A concrete secondary lining is located inside the grid arch frame. Multiple stirrups are provided inside the concrete secondary lining, and the stirrups are fixedly connected to the longitudinal reinforcement inside the concrete secondary lining.

[0009] A connector, one end of which extends into the stirrup and is fixedly connected to the main reinforcement of the secondary concrete lining and the stirrup; the other end of which extends into the grid arch frame.

[0010] The fastener is fixedly connected to the main reinforcement bar of the grid and connected to the connector after being bent in an L-shape.

[0011] Preferably, two connectors are provided at the same connection point between the grid arch and the concrete secondary lining, and the two connectors are located on both sides of the grid arch along the tunnel extension direction.

[0012] Preferably, a waterstop plate is provided at the connector, the waterstop plate is located inside the concrete secondary lining, the connector passes through the middle of the waterstop plate, and the two ends of the waterstop plate extend out of the concrete secondary lining in a U-shape.

[0013] Preferably, the two connectors at the same connection point are connected by the same waterstop plate.

[0014] Preferably, a waterproof layer is provided between the grid arch frame and the concrete secondary lining, and a waterproof membrane is attached to the inner wall of the waterproof layer.

[0015] Preferably, at least two waterproof sealants are provided on the outer wall of the connector.

[0016] Preferably, the joint between the fastener and the connector is provided with sealant.

[0017] Beneficial effects: By adding stirrups during the construction of the internal concrete secondary lining, the stirrups are used to connect and fix the connecting parts, thereby fixing the grid arch frame and the internal steel bars of the concrete secondary lining. As a result, the secondary lining structure will not collapse, which provides great safety protection for on-site personnel and property. Attached Figure Description

[0018] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an undue limitation of the present invention. Wherein:

[0019] Figure 1 This is a cross-sectional schematic diagram of the anti-collapse structure in a specific embodiment provided by this utility model;

[0020] Figure 2 This is a schematic diagram of the installation of the connector in a specific embodiment provided by this utility model;

[0021] Figure 3 for Figure 1 Sectional view along the BB direction;

[0022] Figure 4 This is a schematic diagram of the installation of the grille arch frame in a specific embodiment of this utility model;

[0023] Figure 5 This is a schematic diagram of the connector structure in a specific embodiment provided by this utility model;

[0024] In the diagram: 1—Grid arch frame; 2—Fixed component; 3—Connector; 4—Waterproof membrane; 5—Sealant; 6—Secondary lining main reinforcement; 7—Waterstop plate; 8—Waterstop adhesive; 9—Stirrup; 10—Concrete secondary lining; 11—Waterproof layer; 12—Grid main reinforcement. Detailed Implementation

[0025] The technical solutions in the embodiments of this utility model will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art are within the protection scope of this utility model.

[0026] In the description of this utility model, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," and "bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and do not require that this utility model be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on this utility model. The terms "connected" and "linked" used in this utility model should be interpreted broadly. For example, they can refer to a fixed connection or a detachable connection; they can refer to a direct connection or an indirect connection through intermediate components. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0027] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0028] like Figure 1-5As shown, a large-section tunnel secondary lining anti-collapse structure includes a grid arch frame 1, a concrete secondary lining 10, connectors 3, and fasteners 2. The grid arch frame 1 is an arch-shaped structure adapted to the tunnel. Inside the grid arch frame 1 are multiple grid main reinforcement bars 12 adapted to its shape. There are four grid main reinforcement bars 12, and multiple connecting bars are provided between each grid main reinforcement bar 12 to form an arch-shaped frame to support the tunnel. The concrete secondary lining 10 is located inside the grid arch frame 1. A reinforcing cage is provided inside the concrete secondary lining 10. The reinforcing cage includes secondary lining main reinforcement bars 6 and longitudinal reinforcement bars. The longitudinal reinforcement bars include two layers extending along the tunnel extension direction. Connection points are designed according to the actual tunnel conditions. The stirrups 9 are fixedly connected to the longitudinal reinforcement bars at the corresponding connection points of the concrete secondary lining 10. Specifically… Multiple square stirrups 9 are provided inside the concrete secondary lining 10, each corresponding to a connection point. The stirrups 9 are fitted onto the outside of the four corresponding longitudinal bars. One end of the connector 3 extends into the stirrup 9. The connector 3 is fixedly connected to the secondary lining main bar 6 and the stirrup 9 at the corresponding position by means of steel bar binding or welding, thereby connecting the concrete secondary lining 10 and the grid arch frame 1 into a whole, thus ensuring that the large-section secondary lining structure will not collapse, providing great safety for on-site personnel and property. In order to improve the connection strength of the connector 3, the other end of the connector 3 extends into the grid arch frame 1. The grid arch frame 1 is provided with a fixing member 2, which is fixedly connected to the grid main bar 12 and connected to the connector 3 after being bent in an L-shape.

[0029] In an optional embodiment, multiple connection points are evenly distributed on the same grid arch 1. Two connectors 3 are provided at the same connection point between the grid arch 1 and the concrete secondary lining 10. The connectors 3 can be steel bars. The two connectors 3 are arranged on both sides of the grid arch 1 along the tunnel extension direction to ensure the connection stability between the grid arch 1 and the concrete secondary lining 10 at each connection point.

[0030] A waterstop plate 7 is provided at the connector 3. The waterstop plate 7 can be a rubber plate. The waterstop plate 7 is located inside the concrete secondary lining 10. The connector 3 passes through the middle of the waterstop plate 7. The waterstop plate 7 squeezes the connector 3 through deformation, thereby achieving a seal. Furthermore, two nuts corresponding to the upper and lower surfaces of the waterstop plate 7 are threaded onto the connector 3. The sealing performance is ensured by the compression of the nuts. Furthermore, the two ends of the waterstop plate 7 extend out of the concrete secondary lining 10 in a U-shape, thereby forming a U-shaped enclosure on both sides of the connector 3, thereby improving the sealing ability.

[0031] In an optional embodiment, to reduce installation difficulty, two connectors 3 at the same connection point are connected by the same waterstop 7. A waterproof layer 11 is provided between the grid arch 1 and the concrete secondary lining 10. The waterproof layer 11 can be a waterproof coating, and a waterproof membrane 4 is attached to the inner wall of the waterproof layer 11 to ensure waterproof performance. At least two waterstop adhesives 8 are provided on the outer wall of the connector 3. The waterstop adhesives 8 are evenly and centrally distributed on the connector 3 at a certain interval. Through the tight connection between the various components such as the grid arch 1, the fixing member 2, the connector 3 and the waterstop 7, the stability of the secondary lining structure can be achieved.

[0032] Sealant 5 is provided at the joint between the fastener 2 and the connector 3 to ensure good sealing at the weld and prevent rainwater erosion and rust from causing a decline in its structural mechanical properties. The fastener 2 can be a steel bar, which is bent and then welded to the connector 3, or the end of the fastener 2 is provided with a threaded sleeve to form an L-shaped bend, so that the connector 3 can be fixed to the fastener 2 by means of threaded assembly, reducing the difficulty of installation.

[0033] The connector 3 can be a steel bar with a diameter of 25mm and a length of 80cm or a tie bar with a hook. If it is fixed by welding, the fastener 2 can be an L-shaped steel bar or a steel bar with a diameter of 25mm bent at 90° and a welding length of 20cm.

[0034] The construction method for the anti-collapse structure of the secondary lining of large-section tunnels is as follows:

[0035] Step S1: Mark the device locations on the circumferential and longitudinal spacing above the arch line according to the design. Based on the marked device locations, remove the sprayed concrete on the surface at that location, connect the fixing piece 2 to the main reinforcement of the grid arch frame 1, and apply the waterproof layer 11.

[0036] Step S2: Tie the outer steel bars of the secondary lining structure. The outer steel bars should be connected to the fastener 2. At the same time, the fastener 2 is connected to one end of the connector 3. Sealant 5 is set at the joint, and U-shaped waterstop 7 is set.

[0037] Step S3: Tie the inner reinforcing bars of the secondary lining. The inner reinforcing bars should be connected to the other end of the connector 3. Water-stop adhesive 8 is installed on the connector 3.

[0038] Step S4: Finally, pour concrete to complete the secondary lining construction.

[0039] In an optional embodiment, step S1, the method of connecting and applying the waterproof layer 11 includes:

[0040] S101, the fastener 2 can be an L-shaped steel or a 25mm diameter steel bar bent at 90°. The fastener 2 can be connected to the main reinforcement of the grid arch frame 1 by welding, with a double-sided welding length of about 20cm.

[0041] S102, the waterproof layer 11 can be applied by adhesive or butyl rubber tape, and the other end of the fastener 2 should pass through the waterproof layer 11 and leave a certain length;

[0042] In an optional embodiment, in step S2, the connector 3 is connected and a waterproofing treatment method is used:

[0043] S201, Connector 3 can be a steel bar with a diameter of 25mm and a length of 80cm or a tie bar with a hook. The connection method is welding, and the length of the double-sided weld is about 10cm.

[0044] S202, two waterstop plates 7 are welded to the outer main reinforcement, and a waterstop plate 7 is welded to the connecting piece 3 perpendicular to it.

[0045] In an optional embodiment, step S3 involves the following method for installing the waterproofing adhesive 8:

[0046] S301, two waterproof adhesives 8 are provided at equal intervals in the middle part of the connector 3, which wrap around the surface of the connector 3 and form a certain thickness;

[0047] In one alternative embodiment, the diameter of the reinforcing bars and the strength of the concrete are selected according to actual needs to ultimately ensure the stability of the secondary lining structure.

[0048] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model shall be within the scope of protection of the pending claims of the present utility model.

Claims

1. A collapse-resistant secondary lining structure for large-section tunnels, characterized in that, include: A grid arch frame, the grid arch frame comprising multiple grid main reinforcement bars adapted to its shape; A concrete secondary lining is located inside the grid arch frame. Multiple stirrups are provided inside the concrete secondary lining, and the stirrups are fixedly connected to the longitudinal reinforcement inside the concrete secondary lining. A connector, one end of which extends into the stirrup and is fixedly connected to the main reinforcement of the secondary concrete lining and the stirrup; the other end of which extends into the grid arch frame. The fastener is fixedly connected to the main reinforcement bar of the grid and connected to the connector after being bent in an L-shape.

2. The anti-collapse structure for the secondary lining of a large-section tunnel according to claim 1, characterized in that, Two connectors are provided at the same connection point between the grid arch and the concrete secondary lining, and the two connectors are located on both sides of the grid arch along the tunnel extension direction.

3. The anti-collapse structure for the secondary lining of a large-section tunnel according to claim 2, characterized in that, A waterstop plate is provided at the connector, the waterstop plate is located inside the concrete secondary lining, the connector passes through the middle of the waterstop plate, and the two ends of the waterstop plate extend out of the concrete secondary lining in a U-shape.

4. The anti-collapse structure for the secondary lining of a large-section tunnel according to claim 3, characterized in that, The two connectors at the same connection point are connected by the same waterstop plate.

5. The anti-collapse structure for the secondary lining of a large-section tunnel according to claim 1, characterized in that, A waterproof layer is provided between the grid arch frame and the concrete secondary lining, and a waterproof membrane is attached to the inner wall of the waterproof layer.

6. The anti-collapse structure for the secondary lining of a large-section tunnel according to claim 1, characterized in that, No fewer than two waterproof sealants are provided on the outer wall of the connector.

7. The anti-collapse structure for the secondary lining of a large-section tunnel according to claim 1, characterized in that, Sealant is applied to the joints between the fasteners and connectors.

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