Temporary supporting structure for karst tunnel

Abstract

The utility model discloses a temporary supporting structure for a karst tunnel, relates to the technical field of tunnel supporting, and aims to solve the problems that when rock mass of the karst tunnel is broken, the karst tunnel has the characteristics of large deformation, fast stress release, long duration, rich crack water and the like, and when surrounding rock is greatly deformed, a primary support bears larger surrounding rock pressure; the deformation phenomenon of the primary support can endanger the stability of a tunnel structure and the safety of operators. The utility model provides a karst tunnel temporary supporting structure which comprises a steel arch structure, the steel arch structure comprises an inner-layer I-shaped steel frame and an outer-layer I-shaped steel frame, and the outer surface of the inner-layer I-shaped steel frame and the inner surface of the outer-layer I-shaped steel frame are each provided with a plurality of bolt balls. The bolt balls on the upper layer and the bolt balls on the lower layer are distributed in the same plane in a staggered manner, and the adjacent bolt balls on the upper layer and the bolt balls on the lower layer are connected through steel pipes. Karst deformation can be effectively restrained while the bearing capacity of the supporting structure is guaranteed, and the construction quality and normal use of a tunnel are guaranteed.

Description

TECHNICAL FIELD

[0001] The utility model relates to tunnel support technical field, concretely relates to a karst tunnel temporary support structure. BACKGROUND

[0002] Tunnel is the engineering building buried in stratum, is one form of human utilization of underground space, and the karst tunnel accounts for a high proportion. In the karst tunnel, it is a big problem to guarantee the long-term safety of lining structure. The problems such as lining cracking and inverted arch damage caused by surrounding rock pressure are more and more, and more serious ones can lead to local collapse of the tunnel, so it is particularly important to guarantee the stability of the tunnel structure.

[0003] The rock mass of karst tunnel is broken, has the characteristics such as large deformation, stress release fast, long duration, rich fissure water, and the surrounding rock often has large deformation, the initial support structure will bear large surrounding rock pressure, and the initial support deformation phenomenon is difficult to effectively prevent, which can endanger the stability of the tunnel structure and the safety of the operating personnel. If directly excavated, the surrounding rock will be plastically damaged due to high ground stress, resulting in large deformation or even instability and collapse of the tunnel. The existing general rigid support structure cannot adapt to extrusion large deformation, and even the flexible support is also prone to deformation development due to excessive deformation of the surrounding rock. SUMMARY

[0004] In view of the above problems, the utility model aims at providing a karst tunnel temporary support structure, which can effectively inhibit karst deformation while guaranteeing the bearing capacity of the support structure, and ensure the construction quality and normal use of the tunnel.

[0005] The main idea of the technical scheme adopted by the utility model is that the tunnel is supported by the steel arch structure, a plurality of groups of steel arch structures are arranged along the tunnel direction, and adjacent steel arch structures are connected by beams, and adjacent beams are connected by connecting rods, thereby improving the overall connectivity of the steel arch structure and the stability of the tunnel support structure. In addition, each group of steel arch structures includes an inner I-beam and an outer I-beam, and a bolt ball is arranged on each I-beam along the axial direction. A threaded hole is arranged in the bolt ball, and the inner I-beam is connected to the bolt ball through a threaded anchor rod, and is fixed by a bolt on both sides of the threaded anchor rod. A threaded groove is further arranged on the bolt ball, a spring is arranged in the threaded groove, and the outer I-beam is connected to the threaded groove of the bolt ball through a bolt. The bolt balls are arranged alternately on the inner I-beam and the outer I-beam and connected by steel pipes, thereby improving the stability of the steel arch structure.

[0006] In order to achieve the above purpose, the technical scheme adopted by the utility model is as follows:

[0007] A karst tunnel temporary supporting structure, comprising a steel arch structure, the steel arch structure comprising an inner I-beam and an outer I-beam, the outer surface of the inner I-beam and the inner surface of the outer I-beam each being provided with a plurality of bolt balls, and the plurality of bolt balls of the upper layer and the plurality of bolt balls of the lower layer being staggered in the same plane, and the adjacent bolt balls of the upper layer and the lower layer being connected by a steel pipe.

[0008] By the above technical scheme, further: the bolt ball is provided with a threaded hole, and the threaded hole is arranged along the axis of the bolt ball.

[0009] By the above technical scheme, further: the bolt ball is connected with the inner I-beam through a threaded anchor rod, the threaded anchor rod penetrating the threaded hole, and the two ends of the threaded anchor rod being respectively connected with a nut.

[0010] By the above technical scheme, further: the bolt ball is provided with a threaded groove, and the threaded groove is provided with a spring.

[0011] By the above technical scheme, further: the bolt ball is connected with the outer I-beam through a bolt, and the bolt is threadedly connected with the threaded groove.

[0012] By the above technical scheme, further: the bolt ball comprises a protective shell, a filling layer and a ball core distributed from outside to inside.

[0013] By the above technical scheme, further: the threaded groove is located on the protective shell.

[0014] The beneficial effects of the present application are:

[0015] 1. The steel arch structure supports the tunnel, and a plurality of groups of steel arch structures are arranged along the direction of the tunnel, and adjacent steel arch structures are connected by beams, and adjacent beams are connected by connecting rods, thereby improving the overall connectivity of the steel arch structure and the stability of the tunnel supporting structure.

[0016] 2. In addition, each group of steel arch structures comprises an inner I-beam and an outer I-beam, and the inner I-beam and the outer I-beam are each provided with a bolt ball, the bolt ball is provided with a threaded hole along the axis direction, and the inner I-beam is connected with the bolt ball through a threaded anchor rod, and a bolt is used to fix the threaded anchor rod on both sides.

[0017] 3. The bolt ball is also provided with a threaded groove, the threaded groove is provided with a spring, the outer I-beam is connected with the threaded groove of the bolt ball through a bolt, the bolt balls are staggered on the inner I-beam and the outer I-beam and connected by a steel pipe, thereby improving the stability of the steel arch structure.

[0018] 4. The utility model discloses a karst tunnel temporary support structure, main innovation is the combination of steel arch structure and elastic damping, guarantee the bearing capacity of support structure while, effectively restrain karst deformation, guarantee the construction quality of tunnel and normal use. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 It is steel arch structure schematic diagram of the utility model;

[0020] Figure 2 It is Figure 1 Partial structure enlarged schematic diagram;

[0021] Figure 3 It is bolt ball connection relation schematic diagram of the utility model;

[0022] Figure 4 It is bolt ball solid structure schematic diagram of the utility model of installation bolt;

[0023] Figure 5 It is bolt ball solid structure schematic diagram of the utility model;

[0024] Figure 6 It is overhead schematic diagram of bolt ball of the utility model;

[0025] Figure 7 It is Figure 6 Along A-A section schematic diagram;

[0026] Figure 8 It is overhead schematic diagram of bolt ball of the utility model of installation bolt;

[0027] Figure 9 It is Figure 8 Along B-B section schematic diagram;

[0028] Wherein: 1, inner layer I -shaped steel frame;2, outer layer I -shaped steel frame;3, bolt ball;301, protective shell;302, filling layer;303, ball core;304, thread hole;305, thread groove;306, spring;4, steel pipe;5, bolt;6, crossbeam;7, connecting rod;8, threaded anchor rod. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical scheme and advantage of the embodiments of the application more clear, the technical scheme in the embodiments of the application will be described clearly and completely below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are part of the embodiments of the application, not all the embodiments. The components of the embodiments of the application described and shown in the drawings here can be arranged and designed in various different configurations.

[0030] The inventor has found that the rock mass of karst tunnel has the characteristics of large deformation, fast stress release, long duration, and rich fissure water, and the surrounding rock often deforms greatly. The initial support structure will bear a large pressure from the surrounding rock, and it is difficult to effectively prevent the deformation of the initial support, which will endanger the stability of the tunnel structure and the safety of the workers. If the tunnel is directly excavated, the surrounding rock will be plastically damaged due to high ground stress, resulting in large deformation or even collapse of the tunnel. The existing rigid support structure cannot adapt to the extrusion of large deformation, and even the flexible support is also easily unable to adapt to the development of deformation due to the excessive deformation of the surrounding rock.

[0031] Based on the above findings, the present application provides a temporary support structure for karst tunnel, which supports the tunnel through a steel arch structure. The steel arch structure is provided with multiple groups along the direction of the tunnel, and adjacent steel arch structures are connected by cross beams 6. Adjacent cross beams 6 are connected by connecting rods 7, which improves the overall connectivity of the steel arch structure and further improves the stability of the tunnel support structure. In addition, each group of steel arch structures includes an inner I-beam 1 and an outer I-beam 2. Both the inner I-beam 1 and the outer I-beam 2 are provided with a bolt ball 3. The bolt ball 3 is provided with a threaded hole 304 along the axis direction. The inner I-beam 1 is connected to the bolt ball 3 through a threaded anchor rod 8, and is fixed on both sides of the threaded anchor rod 8 by bolts 5. The bolt ball 3 is also provided with a threaded groove 305, and a spring 306 is arranged in the threaded groove 305. The outer I-beam 2 is connected to the threaded groove 305 of the bolt ball 3 by bolts 5. The bolt balls 3 are arranged alternately on the inner I-beam 1 and the outer I-beam 2 and are connected by steel pipes 4, which improves the stability of the steel arch structure. Embodiment one

[0032] Reference Figure 1 - Figure 9 The present application discloses a temporary support structure for karst tunnel, which adopts a composite lining structure. An initial support is arranged on the surface of the lining layer, which is in close contact with the surrounding rock. A grouting anchoring structure is used to reinforce the surrounding rock on the outside of the tunnel section that needs to be remedied. The existing hollow grouting anchor rod is used.

[0033] A waterproof layer is arranged on the surface of the initial support layer to prevent rusting of steel. The waterproof layer specifically includes a waterproof board, which is wrapped with non-woven geotextile to further improve the waterproof effect. In addition, the surface of other steel structures is also provided with a waterproof coating layer.

[0034] Concrete piles are arranged in rows on the transverse sides of the tunnel excavation contour line, which extend vertically downward from the ground to a certain elevation below the excavation contour line. The top ends of the concrete piles on the same side are fixed with the crown beam above the tunnel, so that the concrete piles are closely connected with the bottom of the upper inverted arch support system.

[0035] A reinforcing mesh is laid under the waterproof layer, and a concrete reinforcing layer is filled under the reinforcing mesh.

[0036] A steel arch structure is arranged under the concrete reinforcing layer, the steel arch structure is in an arch shape and is similar to the shape of the tunnel, and the steel arch structure can support the whole tunnel. Embodiment Two

[0037] Reference Figure 1 - Figure 9 The steel arch structure includes an inner I-beam frame 1 and an outer I-beam frame 2, both of which are in an arch shape, a plurality of bolt balls 3 are arranged on the outer surface of the inner I-beam frame 1 and the inner surface of the outer I-beam frame 2, the plurality of bolt balls 3 in the upper layer and the plurality of bolt balls 3 in the lower layer are staggered and distributed in the same plane, the bolt balls 3 in the upper layer and the bolt balls 3 in the lower layer adjacent to each other are connected by a steel pipe 4, and the inner I-beam frame 1 and the outer I-beam frame 2 are connected stably. The distance between adjacent bolt balls 3 is set according to the net span distance of the tunnel.

[0038] The bolt ball 3 is a multi-layer structure, the outermost layer is a spherical protective shell 301, the inner layer is a spherical core 303, and the space between the protective shell 301 and the spherical core 303 is a hollow filling layer 302 filled with foam or other water-proof filling material. The bolt ball 3 is provided with a threaded hole 304 along the axis direction, and is also provided with a threaded groove 305, the axis of the threaded groove 305 intersects the axis of the threaded hole 304. A spring 306 is arranged in the threaded groove 305, one end of the spring 306 is fixedly connected with the bottom of the threaded groove 305, and the other end is a movable end. In the initial state, when the spring 306 is in the relaxed state, the movable end of the spring 306 is located in the threaded groove 305.

[0039] A circular hole is formed in the inner I-beam frame 1, a threaded anchor rod 8 passes through the circular hole and is threadedly connected with the threaded hole 304 of the bolt ball 3. After the bolt ball 3 and the threaded anchor rod 8 are connected, the positions of the two are adjusted, and then nuts are screwed into the two ends of the threaded anchor rod 8 to limit the positions.

[0040] A circular hole is also formed in the outer I-beam frame 2, a bolt 5 passes through the circular hole and is connected with the threaded groove 305 of the bolt ball 3, and the bolt 5 is screwed in the process of extruding the spring 306, so as to realize elastic shock absorption.

[0041] A plurality of groups of steel arch structures are arranged along the direction of the tunnel, and adjacent steel arch structures are connected by a plurality of parallel arranged cross beams 6. Specifically, the cross beams 6 are respectively welded with the threaded balls on the inner I-beam frames 1 on both sides at the two ends. Adjacent cross beams 6 are connected by a connecting rod 7, the connecting rod 7 is connected with the cross beams 6 on both sides by the bolt 5, which can improve the overall connectivity of the steel arch structure, and further improve the stability of the tunnel supporting structure.

[0042] The basic principle, main features and advantages of the present application are shown and described above. It should be understood by those skilled in the art that the present application is not limited by the above examples, and the above examples and descriptions in the specification are only to illustrate the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A temporary support structure for a karst tunnel, characterized by, The application relates to a steel arch structure, which comprises inner I-shaped steel frames (1) and outer I-shaped steel frames (2), the outer surface of the inner I-shaped steel frames (1) and the inner surface of the outer I-shaped steel frames (2) are respectively provided with a plurality of bolt balls (3), the upper-layer bolt balls (3) and the lower-layer bolt balls (3) are staggered and distributed in the same plane, and adjacent upper-layer bolt balls (3) and lower-layer bolt balls (3) are connected through steel pipes (4).

2. The temporary support structure for karst tunnel according to claim 1, characterized in that: The bolt ball (3) is provided with a threaded hole (304), and the threaded hole (304) is arranged along the axis of the bolt ball (3).

3. The temporary support structure for karst tunnel according to claim 2, characterized in that: The bolt ball (3) is connected with the inner I-shaped steel frame (1) through a threaded anchor rod (8), the threaded anchor rod (8) penetrates the threaded hole (304), and the two ends of the threaded anchor rod (8) are respectively connected with nuts.

4. The temporary support structure for karst tunnel according to claim 3, characterized in that: The bolt ball (3) is further provided with a threaded groove (305), and the threaded groove (305) is provided with a spring (306).

5. The temporary support structure for karst tunnel according to claim 4, characterized in that: The bolt ball (3) is connected with the outer I-shaped steel frame (2) through a bolt (5), and the bolt (5) is screwed with the threaded groove (305).

6. The temporary support structure for karst tunnel according to claim 5, characterized in that: The bolt ball (3) comprises a protective shell (301), a filling layer (302) and a ball core (303) which are distributed from outside to inside.

7. The temporary support structure for karst tunnel according to claim 6, characterized in that: The threaded groove (305) is arranged on the protective shell (301).

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