Anti-faulting lining joint of tunnel crossing through active fault and construction method

Abstract

The application provides a tunnel anti-faulting lining joint crossing a live fault and a construction method, and the lining joint comprises: a primary lining layer; an elastic pad plate, which is located at a live fault of a tunnel and is correspondingly arranged on the inner side of the primary lining layer, the elastic pad plate comprises an inner pad plate and an outer pad plate, and an elastic piece is arranged between the inner pad plate and the outer pad plate; and a secondary lining layer, which extends from both ends of the live fault of the tunnel to the middle along the inner wall of the tunnel, is spaced and distributed in the middle part of the live fault of the tunnel to form an installation station, and a flexible lining block is arranged at the installation station. The flexible lining block is arranged on the live end face of the tunnel to form a flexible support, so that the internal force of the tunnel when a large distance fault occurs is reduced, the lining structure loss is reduced, automatic resetting can be realized under a small fault condition, the damage to the lining support is reduced under a medium fault condition, and post-earthquake repair can be carried out under a large fault condition. Specifically, the prefabricated joint can be cut off after the earthquake, and a new joint is installed to realize post-earthquake repair.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of tunnel support, and particularly relates to an anti-dislocation lining joint for a tunnel crossing an active fault and a construction method. BACKGROUND

[0002] Active faults are widely distributed at home and abroad, and sudden fault dislocation is an important factor causing geological disasters, which has brought great influence on human life and property and engineering safety. The coseismic surface damage, rock mass deformation, strong earthquake and other secondary geological disasters caused by active fault dislocation may impact the tunnel structure crossing the active fault. When a long-distance mountain tunnel is constructed, due to the limitation of natural environment conditions such as topography and geology and the layout of construction design line, the tunnel must cross the active fault. Generally, the tunnel lining belongs to a rigid structure, which will generate a great internal force after forced displacement caused by the surrounding moving rock-soil mass, and finally will be structurally unstable and damaged.

[0003] At present, there are four kinds of design concepts for the protection of tunnels under large dislocation conditions, which are energy isolation, flexible hinge, over-excavation design and application of new materials. The main problems of the traditional tunnel flexible joint are: complex structure, separation of water stop function and anti-dislocation function, and large permanent deformation after a certain dislocation, which causes difficulty in repair.

[0004] Therefore, it is necessary to provide an improved technical solution for the above-mentioned deficiencies of the prior art. SUMMARY

[0005] The purpose of the present application is to overcome the deficiencies in the prior art, and the present application provides an anti-dislocation lining joint for a tunnel crossing an active fault and a construction method.

[0006] In order to achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0007] An anti-dislocation lining joint for a tunnel crossing an active fault, the lining joint comprising:

[0008] An initial support layer;

[0009] An elastic pad plate, which is located at the active fault of the tunnel and is correspondingly arranged on the inner side of the initial support layer, the elastic pad plate comprising an inner pad plate and an outer pad plate, and an elastic member being arranged between the inner pad plate and the outer pad plate;

[0010] A secondary support layer, which extends from both ends of the active fault of the tunnel to the middle along the inner wall of the tunnel, and is spaced and distributed in the middle part of the active fault of the tunnel to form a mounting station, and a flexible lining block is arranged at the mounting station.

[0011] As a preference, the elastic member is a spring, and multiple springs are evenly distributed between the inner pad plate and the outer pad plate.

[0012] As a preference, a rigid pad is arranged between the inner pad plate and the outer pad plate.

[0013] As a preference, the flexible lining block comprises two concrete blocks, and the two concrete blocks are respectively connected to the two sides of the secondary lining;

[0014] An anchoring rib is arranged between the two concrete blocks, and the anchoring rib extends along the length direction of the tunnel, and two ends of the anchoring rib are respectively anchored in the two concrete blocks.

[0015] As a preference, a geomembrane is further arranged between the two concrete blocks, the geomembrane is in an annular structure matched with the diameter of the tunnel, and two ends of the geomembrane are respectively embedded in the two concrete blocks.

[0016] As a preference, the flexible lining block is a prefabricated part, and the anchoring rib and the geomembrane are prefabricated in the flexible lining block.

[0017] As a preference, the inner walls of the two concrete blocks are respectively provided with a tongue-and-groove at one end away from each other, and the secondary lining is provided with a receiving port corresponding to the tongue-and-groove.

[0018] As a preference, the two concrete blocks are filled with a flexible filler.

[0019] As a preference, the flexible lining block is a block-shaped assembled part, and multiple flexible lining blocks are assembled in a ring structure corresponding to the tunnel along the circumferential direction of the tunnel.

[0020] A construction method of a fault-resistant lining joint of a tunnel passing through an active fault, the method comprising:

[0021] Step S1, applying a primary lining to the inner wall of the tunnel;

[0022] Step S2, erecting a formwork trolley at the active fault of the tunnel, and placing an elastic pad plate on the top of the trolley;

[0023] Step S3, placing a flexible lining block, and then applying a secondary lining to one end of the active fault of the tunnel, and then applying a secondary lining to the other end of the active fault of the tunnel;

[0024] Step S4, after the tunnel support structure reaches the design strength, removing the formwork trolley.

[0025] Beneficial effect: flexible blocks are arranged at the active end face of the tunnel to form flexible support, reduce the internal force when the tunnel has large distance misalignment, reduce the lining structure loss, can realize automatic reset under small misalignment condition, reduce the damage to the lining support under medium misalignment condition, and perform post-earthquake repair under large misalignment condition, specifically, the prefabricated joint can be cut off after the earthquake, and a new joint is installed for reinforcement treatment, so as to realize the post-earthquake repair function. BRIEF DESCRIPTION OF DRAWINGS

[0026] The drawings accompanying the specification of the present application form a part thereof and serve to provide further understanding of the application, the illustrative embodiments of the application and its description serve to explain the application. The drawings are not intended to limit the application in any way.

[0027] Fig. 1 The lining joint structure diagram in the specific embodiment provided by the present application;

[0028] Fig. 2 The lining joint distribution schematic diagram in the specific embodiment provided by the present application.

[0029] In the drawings: 1, lining joint; 2, tunnel;

[0030] 101, two lining layers; 102, primary lining layer; 103, rigid pad; 104, spring; 105, inner pad plate; 106, outer pad plate; 107, concrete block; 108, geomembrane; 109, anchoring bar; 110, tongue and groove. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments in the present application belong to the scope of protection of the present application.

[0032] In the description of the present application, the orientations or positional relationships indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application, not for requiring the present application to be constructed and operated in a specific orientation, therefore, cannot be understood as a limitation to the present application. The terms "connected", "connected" used in the present application should be understood broadly, for example, can be fixed connection, can also be detachable connection; can be directly connected, can also be indirectly connected through intermediate components. For those skilled in the art, the specific meanings of the above terms can be understood according to the specific circumstances.

[0033] 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.

[0034] like Figs. 1-2 As shown, a fault-resistant lining joint for tunnels crossing active faults is installed at the active fault of tunnel 2. The lining joint 1 includes an initial support lining 102, an elastic pad, and a secondary support lining 101. The initial support lining 102 is a shotcrete layer, supported by an elastic pad after reaching a preset strength on the inner side. An elastic pad is installed at the active fault of the tunnel, located inside the initial support lining. The elastic pad includes an inner pad 105 and an outer pad 106. The inner pad 105 is pressed tightly against the inner wall of the initial support lining 102 by a template trolley. An elastic element is provided between the inner pad 105 and the outer pad 106 to reduce the internal force when the tunnel experiences a large fault, thereby reducing the loss of the lining structure. The secondary support lining... Layer 101 extends along the inner wall of the tunnel from both ends of the active fault towards the middle. The second lining layer 101 is a concrete layer. The second lining layer 101 can be an integral prefabricated layer, a shotcrete layer, or a sheet-like assembled layer. The specific structure of the second lining layer 101 is not limited here. The second lining layer 101 is distributed at intervals in the middle of the active fault of the tunnel to form installation positions. Flexible lining blocks are provided at the installation positions. The flexible lining blocks can be carried when the tunnel deforms. Under small misalignment conditions, the elastic pad can be automatically reset through the elastic element. Under medium misalignment conditions, it reduces damage to the lining support. Under large misalignment conditions, the elastic pad and flexible lining block can be removed for post-earthquake repair.

[0035] In an optional embodiment, the elastic element is a spring 104, with its two ends connected to an inner pad 105 and an outer pad 106, respectively. To ensure the stability of the connection, blind holes corresponding to the spring 104 are provided on the inner pad 105 and the outer pad 106, and multiple springs 104 are evenly distributed between the inner pad 105 and the outer pad 106. Specifically, the springs 104 are distributed in a quincunx pattern between the inner pad 105 and the outer pad 106. More preferably, the axial direction of each spring 104 coincides with the radial direction of the tunnel, so that the force of each spring 104 acts directly on the staggered force direction of the tunnel end face.

[0036] In this embodiment, the two ends of the spring 104 are fixed to the inner pad 105 and the outer pad 106 by welding or other means.

[0037] In the embodiment, the rigid pads 103 are arranged between the inner pad plate 105 and the outer pad plate 106, and the rigid pads 103 can be annular or columnar. When the rigid pads 103 are columnar, the length of the rigid pads 103 is adapted to the length of the spring 104. The rigid pads 103 are in multiple groups, and each group of the rigid pads 103 is uniformly distributed along the cross section of the tunnel in the circumferential direction. The two ends of the rigid pads 103 are fixed between the inner pad plate 105 and the outer pad plate 106 by welding. The inner pad plate 105 and the outer pad plate 106 can also be provided with blind holes for mounting the rigid pads 103, so as to form annular support. The support force is provided in the axial direction of the tunnel without affecting the deformation amount of the elastic pad plate. The rigid pads 103 have a certain support force, so as to ensure the stability of the support. Preferably, the rigid pads 103 are in multiple groups, and the multiple groups of the rigid pads 103 are uniformly distributed in the length direction of the tunnel. Specifically, the rigid pads 103 can be in two groups or three groups.

[0038] When the rigid pads 103 are annular, the annular shape is corresponding to the contour of the tunnel. The rigid pads 103 are adapted to the cross-sectional contour. The two sides of the rigid pads 103 are connected between the inner pad plate 105 and the outer pad plate 106. The rigid pads 103 are in multiple groups, and the multiple groups of the rigid pads 103 are uniformly distributed in the length direction of the tunnel. Specifically, the rigid pads 103 can be in two groups or three groups. Preferably, the inner pad plate 105 and the outer pad plate 106 are each provided with an annular groove corresponding to the rigid pads 103.

[0039] In the embodiment, the inner pad plate 105, the outer pad plate 106 and the rigid pads 103 are all made of steel and have a certain thickness, for example, 1.5-3 cm.

[0040] In another optional embodiment, in order to ensure that the concrete or stone enters between the inner pad plate 105 and the outer pad plate 106 during the construction of the two lining layers 101, a flange extending outward is arranged at the edge of the inner pad plate 105 to form an annular assembly groove. The outer pad plate 106 is arranged in the assembly groove in a shape corresponding to the shape of the assembly groove, that is, an annular plate. Thus, the rigid pads 103 and the spring 104 are closed. The outer pad plate 106 is not fixed with the inner pad plate 105, but is only supported by the spring 104 and the rigid pads 103. In the embodiment, the inner pad plate 105 and the outer pad plate 106 are both spliced pieces. After a plurality of inner pad plates 105 and a plurality of outer pad plates 106 are connected correspondingly, an integral whole is formed. The plurality of inner pad plates 105 and the plurality of outer pad plates 106 are spliced in the circumferential direction of the tunnel to form a complete annular structure corresponding to the tunnel. The adjacent inner pad plates 105 are fixed by welding. Correspondingly, when the rigid pads 103 are annular in the embodiment, the rigid pads 103 are also annular structures formed by splicing a plurality of spliced pieces, which is beneficial to more accurate installation.

[0041] In another alternative embodiment, according to the length of the tunnel active fault, the lining joint 1 can be multiple, and the multiple lining joints 1 can be arranged in parallel or at intervals in the extension direction of the tunnel 2.

[0042] In another alternative embodiment, the flexible lining block includes two concrete blocks 107, the outer wall of the concrete block 107 is an arc surface corresponding to the inner wall of the inner backing plate 105, and the inner wall of the concrete block 107 is an arc surface adapted to the two supporting layers 101. The two concrete blocks 107 are connected to the two supporting layers 101 on both sides of the installation station, respectively. An anchoring bar 109 is arranged between the two concrete blocks 107, the anchoring bar 109 extends along the length direction of the tunnel, and both ends of the anchoring bar 109 are anchored in the two concrete blocks 107, respectively, preferably extending into the concrete blocks by a certain depth, for example, extending to the middle of the concrete blocks, or extending into one third, and of course, the anchoring bar 109 can also penetrate through the concrete blocks. In this embodiment, the anchoring bar 109 is a micro-NPR steel material, which can exhibit the characteristics of constant resistance shear and energy absorption of the micro-NPR steel material in the case of large displacement. Both ends of the anchoring bar 109 are connected to anchoring plates or anchoring blocks, which form a stable anchoring state after being poured into the concrete blocks 107, thereby ensuring the anchoring effect, and at the same time, the middle part of the anchoring bar 109 deforms to adapt to the deformation of the tunnel active end surface when deformation occurs.

[0043] In this embodiment, a geomembrane 108 is further arranged between the two concrete blocks 107, and the geomembrane 108 is arranged on the side of the anchoring bar 109 close to the tunnel axis. The geomembrane 108 is in a ring structure adapted to the diameter of the tunnel, and both ends of the geomembrane 108 are embedded in the two concrete blocks 107, preferably extending into the concrete blocks by a certain depth, for example, extending to the middle of the concrete blocks, or extending into one third, thereby forming a seal between the two concrete blocks 107, thereby avoiding seepage events at the tunnel active fault. Both ends of the geomembrane 108 are fixed with the concrete blocks 107 by pouring.

[0044] In another alternative embodiment, the flexible lining block is a prefabricated part, and the anchoring bar 109 and the geomembrane 108 are prefabricated in the flexible lining block by pouring, thereby being able to be quickly installed in the elastic backing plate, reducing the construction period, and improving the construction effect.

[0045] In another alternative embodiment, the end of the inner wall of the concrete block 107 away from each other is provided with a tongue-and-groove 110, and the end of the two supporting layers 101 is provided with a receiving port corresponding to the tongue-and-groove 110. The inner wall of the concrete block 107 is adapted to the inner wall of the two supporting layers 101, thereby forming a complete inner wall surface. In this embodiment, the two supporting layers 101 are fixed to the concrete block 107 through the receiving port of the tongue-and-groove 110, thereby ensuring the stability of the flexible lining. In addition, the tongue-and-groove 110 is connected in the form of a tongue-and-groove, which is simple in structure and convenient for removing the elastic backing plate and the flexible lining block for post-earthquake repair.

[0046] In another alternative embodiment, flexible filler is filled between two concrete blocks 107, and the flexible filler can be GB flexible filler, and of course, the flexible filler can also be other composite materials which are not sensitive to temperature and have anti-seepage property. In the present embodiment, the flexible filler is filled in the gap on both sides of the geomembrane 108.

[0047] In another alternative embodiment, the flexible lining block is a block assembly, and a plurality of flexible lining blocks are spliced into a ring structure corresponding to the tunnel 2 along the circumference of the tunnel, which is beneficial to more accurate installation. In order to ensure stability, a mortise and tenon structure is arranged between two adjacent flexible lining blocks in the circumferential direction of the tunnel for connection. Specifically, a strip-shaped protrusion extending in the length direction of the tunnel is arranged at one end of the flexible lining block, and a groove corresponding to the strip-shaped protrusion is arranged at the other end of the flexible lining block.

[0048] The present application also provides a construction method of the fault-resistant lining joint 1 for tunnel crossing through an active fault. The lining joint 1 is arranged at the active fault of the tunnel, and the construction method comprises the following steps:

[0049] Step S1, an initial support lining 102 is applied to the inner wall of the tunnel; step S2, a formwork trolley is erected at the active fault of the tunnel, and an elastic pad is placed on the top of the trolley; step S3, after the elastic pad is placed, the flexible lining block is placed through the formwork trolley, then the second support lining 101 located at one end of the active fault of the tunnel is applied, and then the second support lining 101 located at the other end of the active fault of the tunnel is applied, and the second support linings 101 at both ends and the flexible lining block form an integral whole; step S4, after the cast part reaches the design strength, the formwork trolley is removed. In the present embodiment, for the case that the active fault zone is relatively long, a plurality of lining joints 1 can be arranged at a certain interval in the longitudinal direction.

[0050] In the present embodiment, the elastic pad is placed on the top of the formwork trolley, and the elastic pad can be of an integral type or a piece splicing structure, and the second support lining 101 can be of an integral assembly type or a piece type. The flexible lining block comprises two concrete blocks 107, and the two concrete blocks 107 are provided with an anchor bar 109, a geomembrane 108 and a flexible filler; the anchor bar 109 is micro-NPR steel material, and the geomembrane 108 and the GB flexible filler.

[0051] The flexible lining block can be prefabricated, and the flexible lining block with micro-NPR steel material, geomembrane 108 and filler is prefabricated to increase the bonding force. The flexible lining block can also be cast, and the flexible lining block is directly cast together with the second support lining 101, so that the flexibility is high.

[0052] In the small error distance condition, the automatic reset can be realized; in the medium error distance condition, the damage to the lining support (primary support deformation caused by joint failure) is reduced; in the large error distance condition, the post-earthquake repair function can be realized, that is, under the "edge resistance and edge yield" effect of the elastic pad and the micro NPR steel, the overall deformation is small, the stress is concentrated only at the micro NPR steel, after the earthquake, the lining joint 1 can be cut off, a new joint is installed, and reinforcement treatment is performed at the installation position, so that the post-earthquake repair function is realized.

[0053] The above merely describes the preferred embodiments of the present application, and is not used to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application is within the protection scope of the claims of the present application.

Claims

1. A fault-resistant lining joint for tunnels crossing active faults, characterized in that, The lining joint includes: Initial support lining; An elastic pad is located at the active fault of the tunnel and is correspondingly disposed inside the initial support lining. The elastic pad includes an inner pad and an outer pad, and an elastic element is provided between the inner pad and the outer pad. Two lining layers extend along the inner wall of the tunnel from both ends of the active fault to the middle, and are spaced apart in the middle of the active fault to form installation positions. Flexible lining blocks are provided at the installation positions. The elastic element is a spring, and multiple springs are evenly distributed between the inner pad and the outer pad. A rigid pad is provided between the inner pad and the outer pad; The flexible liner includes two concrete blocks, which are respectively connected to the two liner layers on both sides of the installation station. An anchor bar is provided between the two concrete blocks, the anchor bar extends along the length of the tunnel, and its two ends are respectively anchored inside the two concrete blocks. A geomembrane is also provided between the two concrete blocks. The geomembrane is a ring structure adapted to the diameter of the tunnel, and the two ends of the geomembrane are pre-embedded inside the two concrete blocks. The flexible liner is a prefabricated component, and the anchoring bars and the geomembrane are prefabricated inside the flexible liner. The inner walls of the concrete blocks are provided with tongue and groove joints at opposite ends, and the ends of the two lining layers are provided with corresponding receiving joints extending into the tongue and groove joints.

2. The anti-fault lining joint for tunnels crossing active faults according to claim 1, characterized in that, Flexible filler is used to fill the space between the two concrete blocks.

3. The anti-fault lining joint for tunnels crossing active faults according to claim 1, characterized in that, The flexible liner is a block-shaped assembly, and multiple flexible liners are spliced ​​together along the circumference of the tunnel to form a ring structure corresponding to the tunnel.

4. A construction method for an anti-fault lining joint for a tunnel crossing a live fault, wherein the anti-fault lining joint as described in any one of claims 1-3 is installed at the live fault of the tunnel, characterized in that, include: Step S1: Apply the initial support lining to the inner wall of the tunnel; Step S2: Erect a formwork trolley at the active fault of the tunnel and place an elastic pad on top of the trolley. Step S3: After placing the flexible liner, construct two liner layers at one end of the active fault of the tunnel, and then construct two liner layers at the other end of the active fault of the tunnel. Step S4: After the tunnel support structure reaches the design strength, remove the formwork trolley.

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