CN-224214198-U - Flexible protection device for tunnel top collapse cavity treatment

CN224214198UCN 224214198 UCN224214198 UCN 224214198UCN-224214198-U

Abstract

The utility model discloses a flexible protection device for treating a collapse cavity at the top of a tunnel, which comprises at least two flexible protection nets, wherein the flexible protection nets are distributed from top to bottom, the lower hole diameter of each flexible protection net is smaller than the upper hole diameter of each flexible protection net, and the flexible protection net is connected to the inner wall of the collapse cavity. The protective net consists of a steel wire rope protective net and a twisted hexagonal flexible net, wherein the steel wire rope protective net is woven by the diamond of the Golgi coated steel wire rope, and the protective net is woven by A-level Golgi coated steel wires and overlapped with the edge of the steel wire rope protective net by 10-20 cm for binding. The steel wire rope protective net is spliced by meshes with different specifications, and the splicing is connected by using steel wire rope buckles according to a specific principle. The device is also provided with components such as anchor rods, spring hooks and the like, and the number and the size of each component are determined according to the three-dimensional data of the collapsed cavity. Compared with the traditional protective screening, the device can effectively absorb falling stone energy, has good buffering effect, strong adaptability to different collapse cavities, is simple and convenient to install, can reduce construction risk, and ensures tunnel construction and operation safety.

Inventors

XIA JIALIN
SONG HUIXING
SUN KEGUO
XU WEIPING
LIU ZHILI
FENG SHUBIAO

Assignees

中铁十四局集团第二工程有限公司
西南交通大学

Dates

Publication Date: 20260508
Application Date: 20250224

Claims (10)

1. The flexible protection device for treating the collapse cavity at the top of the tunnel is characterized by comprising a flexible protection net, wherein at least two flexible protection nets are distributed from the inside of the collapse cavity (1) at the top of the tunnel from top to bottom, and the aperture of the flexible protection net below is smaller than that of the flexible protection net above; The protection air bag comprises a top surface part, a bottom surface part and a side surface part which is connected with the top surface part and the bottom surface part and surrounds a circle at the side, the bottom surface part of the protection air bag is provided with an inflation inlet and an exhaust port, and a tubular exhaust channel which is communicated with the exhaust port and extends into the inner cavity of the protection air bag is arranged in the protection air bag; The tubular exhaust passage is constructed in an L shape and comprises a transverse passage part which is attached to the inner wall of the top surface part of the air bag and the tail end of which is communicated with the inner cavity of the air bag, and a vertical passage part which is attached to the inner wall of the side surface part of the air bag and the tail end of which is communicated with the exhaust port, and the tail end of the transverse passage part of the tubular exhaust passage is close to or positioned at the center position of the air bag; The protection air bag is constructed to be capable of carrying out conformal blocking on the bottom opening of the cavity collapsed at the top of the tunnel after the inflation port is inflated so as to form a temporary support, and is also constructed to be capable of injecting concrete into the protection air bag from the inflation port under the inflation state of the temporary support so as to enable the protection air bag to be converted into a permanent support from the temporary support.
2. The flexible protection device according to claim 1, wherein the flexible protection net comprises a first flexible protection net and a second flexible protection net which are arranged from top to bottom, the first flexible protection net is a steel wire rope protection net (4) which is made of a Golgi coated steel wire rope in a diamond mesh weaving mode, the second flexible protection net is formed by paving a double-twisted hexagonal flexible net (5) on the steel wire rope protection net (4), the double-twisted hexagonal flexible net (5) is woven by adopting A-level Golgi coated steel wires, and the double-twisted hexagonal flexible net is formed by overlapping the edge of the steel wire rope protection net to 10-20 cm below for binding.
3. A flexible protection device according to claim 2, characterized in that each wire rope protection net (4) is formed by splicing a plurality of prefabricated wire rope net sheets of different specifications.
4. A flexible guard according to claim 3 wherein the preformed wire rope meshes are spliced with large mesh placed below and small mesh placed above and spliced from the centre to the periphery with a minimum overlap width no less than the distance of one mesh.
5. The flexible protection device according to claim 4, further comprising wire rope buckles (6) for connecting wire rope meshes, wherein the wire rope buckles (6) are composed of a U-shaped ring and a set of bolt fasteners, at least one wire rope buckle (6) is installed in each overlapped mesh when the wire rope meshes are connected, and the distance between every two adjacent wire rope buckles (6) is at least 50mm.
6. The flexible protection device according to claim 5, further comprising a plurality of anchor rods (3), wherein the anchor rods (3) are anchored on the inner wall of the cavity (1) at the top of the tunnel, the end heads are of annular design, and all the anchor rods (3) are subjected to surface pretreatment in advance for corrosion prevention treatment and are arranged in a quincuncial shape.
7. The flexible protection device according to claim 6, further comprising a spring hook (7), wherein the spring hook (7) is composed of a hook end, a clamp end and a middle section spring connecting the hook end and the clamp end, the hook end is connected with an annular end of the anchor rod (3) on the inner wall of the collapse cavity (1) at the top of the tunnel, the clamp end is used for clamping an edge rope of the steel wire rope protection net (4), the middle section spring is a circular spiral tension spring, and the maximum extension amount allowed by the spring hook is 0.5 m.
8. The flexible protection device according to claim 7, wherein the outer surface of the hook end and the inner surface of the clamp end clamping hole of the spring hook (7) are provided with rubber anti-skid sleeves.
9. The flexible protection device according to claim 8, wherein when the transverse span of the steel wire rope protection net (4) is larger than 6 meters, a cable-stayed anchor rope (8) is additionally arranged for fixing, one end of the cable-stayed anchor rope (8) is connected with the steel wire rope protection net (4), the other end of the cable-stayed anchor rope is connected with the annular head anchor rod (3) on the inner wall of the collapse cavity (1), and the cable-stayed anchor rope (8) is provided with a decompression ring.
10. The flexible protection device according to any one of claims 1-9, wherein the number and size of the components in the flexible protection net is determined based on three-dimensional structural data acquired by scanning the tunnel roof collapse cavity (1).

Description

Flexible protection device for tunnel top collapse cavity treatment Technical Field The utility model belongs to the technical field of tunnel construction, and particularly relates to a flexible protection device for treating a collapse cavity at the top of a tunnel. Background The flexible protecting net is used for covering and wrapping the slope or rock to be protected so as to limit the weathering exfoliation or damage of the slope rock soil body and dangerous rock collapse or control falling rocks to move within a certain range to play a role of enclosing, and is mainly divided into an active flexible protecting net and a passive flexible protecting net. While the traditional active net needs a large number of anchor rods in the protection range, and consumes a large number of net sheets, the traditional passive net needs a large enough strength to directly bear the impact of falling rocks, and needs periodic inspection and repair in the later period, so that the manufacturing cost and the long-term maintenance cost are high. Along with the continuous progress of the technology, the flexible protective net has mature technology and strong applicability, but is mainly used in the field of preventing and controlling the falling rocks of the side slope so far, and has relatively few protective cases applied in the field of tunnel construction. In the tunnel construction process, due to complex and changeable geological conditions, cavity collapse treatment is a problem which is difficult to avoid in many tunnel engineering. For example, the TBM construction technology widely applied to construction of hydraulic tunnels and traffic tunnels has the remarkable advantages of rapidness, high efficiency, safety, reliability and the like, but due to the special slag discharging mode and vibration influence generated during tunneling, surrounding rock collapses easily when the TBM passes through joint crack development and surrounding rock breaking sections, so that a collapse cavity is formed. For cavity collapse treatment, various treatment methods have appeared in the field of tunnel engineering, such as adopting modes of shotcrete to stabilize the free surface, pumping concrete to backfill and the like. However, these methods have certain limitations, such as unstable treatment effect and easy secondary collapse. Meanwhile, according to the actual conditions of the construction site, different treatment measures are required for different positions, different degrees and different types of collapse cavities. When a cavity is collapsed above the arch part of a tunnel region of an excavated support, the tunnel arch part can be directly impacted if the buffer device is not blocked in the face of sudden falling rocks. If the rock mass falling from the collapse cavity is large in volume or has the condition of falling rocks for a long time in the tunnel operation process, the impact of the falling rocks on the arch is large or accumulated continuously, the service life of the tunnel can be reduced, even the damage of the arch and the like possibly occur in the later period, serious potential safety hazards exist, the normal use and the safe passing of the tunnel are influenced, and a large amount of financial resources, material resources and time are consumed for maintenance treatment. Disclosure of utility model Aiming at the problems of the prior art, the utility model aims to provide a flexible protection device for treating the cavity collapse at the top of a tunnel, so as to solve the problems of the traditional tunnel cavity collapse treatment method and protection nets, reduce the risk of falling rocks of the cavity collapse by a unique protection net structure, component arrangement and parameter determination mode, improve the tunnel construction and operation safety, and ensure the normal use of the tunnel and the passing safety of personnel and vehicles. The technical scheme adopted by the utility model is as follows: The utility model discloses a flexible protection device for treating a collapse cavity at the top of a tunnel, which comprises a flexible protection net, wherein at least two layers of flexible protection nets are distributed from top to bottom in the collapse cavity at the top of the tunnel, the aperture of the flexible protection net below is smaller than that of the flexible protection net above, and the flexible protection net is connected to the inner side wall of the collapse cavity at the top of the tunnel. According to the utility model, the flexible protective net structures with different apertures and distributed from top to bottom can better adapt to the impact of falling rocks, and the protective net with smaller apertures below can effectively intercept smaller fragments filtered by the protective net above, so that the protective effect is improved. Meanwhile, the connection mode with the inner wall of the cavity collapsed at the top of the tunnel ensures the installation