CN-121976828-A - Construction method and supporting equipment for collapse area of weak surrounding rock tunnel

CN121976828ACN 121976828 ACN121976828 ACN 121976828ACN-121976828-A

Abstract

The invention provides a construction method and support equipment for a collapse area of a weak surrounding rock tunnel, which comprises the following steps of S1, backfilling back pressure on a collapse area of a hollow cavity to form a stable slope body after the tunnel collapses, spraying concrete to form a closed surface, S2, constructing a support for the collapse deformation limited area of the tunnel to complete support, S3, expanding and excavating one end of the collapse deformation limited area of the tunnel away from the closed surface, S4, constructing a pipe shed working chamber by an expanding and excavating section, constructing a guide wall, S5, constructing an advance pipe shed at the guide wall, grouting construction on the advance pipe shed, S6, after the grouting construction is completed and the design strength is reached, excavating and supporting construction on the hollow area of the tunnel, S7, completing the collapse section construction, removing the support, and continuing the tunnel construction. The invention provides a treatment process of backfill back pressure, temporary support and advance pipe shed grouting, which solves the problem of secondary collapse risk caused by arch replacement in the traditional method, realizes cooperative and stable control of collapse cavities and deformation limited areas, and ensures construction safety.

Inventors

ZENG GUANGBIN
Cheng nuo
YANG XIAOJUN
FENG DEDING
YIN CAO
YANG XIANGDONG
ZHANG DEREN
SUN JIA
LIU JINGYU
CHEN CHAOQIAN

Assignees

长江国际水利水电工程建设有限公司
中交第二航务工程局有限公司

Dates

Publication Date: 20260505
Application Date: 20260224

Claims (10)

1. A construction method of a collapse area of a weak surrounding rock tunnel is characterized by comprising the following steps: s1, after a tunnel collapses, backfilling back pressure is carried out on the cavity collapse area to form a stable slope body (101); performing closed reinforcement construction on the slope by spraying concrete to form a closed surface (103); s2, constructing a bracket (107) in a tunnel collapse deformation limit area to finish supporting; S3, enlarging and digging one end of the tunnel collapse deformation limited area far away from the sealing surface (103); s4, constructing a pipe shed working chamber (104) by the expanding and digging section, and constructing a guide wall (105); s5, constructing an advance pipe shed (106) at the guide wall (105), and grouting the advance pipe shed (106); S6, after grouting construction is completed and the design strength is reached, excavating and supporting construction are carried out on the cavity area of the tunnel, and the length of the supporting section reaches the tail end of the pipe shed; s7, the construction of the collapse section is completed, the support (107) is removed, and the tunnel construction is continued.
2. The construction method of the weak surrounding rock tunnel collapse area according to claim 1, wherein in S3 and S4, the expanding and digging area is the top end and the side edge of the tunnel, the expanding and digging form a tunnel face, and the guide wall (105) is arranged at the tunnel face; the length of the digging section is required to ensure that the construction of the advance pipe shed (106) is not influenced; the foreline shed (106) comprises a plurality of grouting steel pipes for grouting.
3. The construction method of the collapse area of the weak surrounding rock tunnel according to claim 1, wherein the construction length of the leading pipe shed (106) is required to exceed the collapse cavity (102) and extend forwards; the steel pipes of the advance pipe shed (106) are connected in sections, the length of each section is not less than 2m, the joint staggering distance of adjacent steel pipes is more than 1m, and all sections are connected by screw threads or sleeve welding, and the connection length is not less than 50mm.
4. The construction method of the collapse area of the weak surrounding rock tunnel according to claim 1, wherein the bracket (107) comprises a plurality of supporting beams, and the adjacent supporting beams are connected and fixed through connecting ribs to form the bracket (107) of the shed frame system; the supporting beam is I-steel, and the supporting beam supports the top surface and the side of the tunnel collapse deformation limit area and is fixed on the ground.
5. The construction method of the weak surrounding rock tunnel collapse area according to claim 1, wherein the support (107) adopts supporting equipment, and when the support is arranged, the construction method comprises the following steps: s21, supporting equipment is connected with a frame structure, and the frame structure is adapted to a tunnel; S22, the supporting equipment moves to a tunnel collapse deformation limit area through wheels; S23, the frame body structure is opened against the inner wall of the collapse deformation limit area of the tunnel, so that support is completed; the middle part of the frame body structure is provided with a door opening for constructors and construction equipment to enter and exit.
6. The supporting equipment for the collapse area of the weak surrounding rock tunnel is characterized by comprising a plurality of supporting plates (2), wherein the supporting plates (2) are shaped like a Chinese character 'men'; The supporting plate (2) is provided with a plurality of telescopic pieces (7), the telescopic pieces (7) positioned on the side face are connected with the side frames (3), and the telescopic pieces (7) positioned on the top are connected with the top frames (6); The two sides of the top end of the supporting plate (2) are provided with adjusting pieces (8), and the adjusting pieces (8) are connected with corner brackets (6); the side frames (3), the top frames (5) and the corner frames (6) are opened to jointly support the collapse deformation limit area of the tunnel.
7. The supporting device for the collapse area of the weak surrounding rock tunnel according to claim 6 is characterized in that two bottom plates (4) are arranged at the bottom of the supporting plate (2), and the two bottom plates (4) are arranged at two ends of the bottom of the supporting plate (2); the bottom plate (4) is rotationally connected with a plurality of rollers (402); a plurality of through holes (401) are arranged in the bottom plate (4) and are used for inserting anchor rods; or a grouting pipe is inserted into the through hole, and the bottom plate (4) is fixed and supported through grouting.
8. The supporting equipment for the collapse area of the soft surrounding rock tunnel according to claim 6, wherein the telescopic piece (7) comprises a plurality of first fixing frames (701) fixedly connected with the supporting plate (2); the first fixing frame (701) is provided with a first telescopic rod (702); a connecting plate (703) is arranged at the end part of the first telescopic rod (702); a plurality of first threaded columns (704) are arranged on one side of the side frame (3) or the top frame (5) close to the supporting plate (2), and the first threaded columns (704) penetrate through the connecting plate (703); The first threaded column (704) is connected with a knob (705) in a threaded mode, and the knob (705) abuts against the connecting plate (703).
9. The supporting equipment for the collapse area of the soft surrounding rock tunnel according to claim 6, wherein the adjusting piece (8) comprises a plurality of second fixing frames (801) fixedly connected with the supporting plate (2); the second fixing frame (801) is provided with a second telescopic rod (802); The novel corner bracket also comprises a plurality of connecting rods (803), wherein one side of each connecting rod (803) close to the corner bracket (6) is a cambered surface, and the cambered surface is matched with the corner bracket (6); The connecting rod (803) is provided with a hinging block (806); a plurality of second threaded columns (804) are arranged on the inner sides of the corner brackets (6), and the second threaded columns (804) penetrate through the connecting rods (803); the second threaded column (804) is in threaded connection with a connecting sleeve (805), and the connecting sleeve (805) props against the connecting rod (803); the output end of the second telescopic rod (802) is hinged with the connecting rod (803) through a hinging block (806); The supporting plate (2) is provided with a fixed rod (807), and a plurality of third telescopic rods (808) are arranged between the fixed rod (807) and the connecting rod (803); One end of a third telescopic rod (808) is hinged with the fixed rod (807), and the other end is hinged with the connecting rod (803) through a hinging block (806); The second telescopic rod (802) and the third telescopic rod (808) are connected with different connecting rods (803).
10. The supporting device for the collapse area of the weak surrounding rock tunnel according to claim 6 is characterized in that the side frames (3), the top frames (5) and the corner frames (6) comprise a plurality of supporting rods, and the radian of each supporting rod is matched with the tunnel; a plurality of cross beams are arranged between the adjacent support rods and used for stabilizing the support rods; Support bar far away from the support plate (2) a guard board is arranged on one side of the cover board.

Description

Construction method and supporting equipment for collapse area of weak surrounding rock tunnel Technical Field The invention relates to the technical field of tunnel construction, in particular to a construction method and supporting equipment for a collapse area of a weak surrounding rock tunnel. Background In the construction process of the V-level weak surrounding rock tunnel, the rock mass is low in compressive strength (usually less than or equal to 0.8 MPa), loose in structure and poor in cementation, and the problems of groundwater penetration, surrounding rock weathering and crushing and the like often exist in poor geology segments, so that the collapse of the tunnel face is easily caused. After collapse, irregular cavities are easily formed in the upper part of surrounding rock, the volume of each cavity can reach tens to hundreds of cubic meters, meanwhile, the primary support structure in the range of 3-5m around the face can generate large deformation limit invasion due to surrounding rock extrusion, the limit invasion displacement is usually more than 20cm, and the support structure can be cracked and peeled off when serious, so that the support structure cannot be carried continuously. At present, the treatment mode of the compound disasters in the industry is single, and a process of sealing before replacing is generally adopted: Firstly, adopting sprayed concrete to initially spray and seal the exposed slope surface of the collapse cavity, wherein the spraying thickness is usually 10-15cm, only surface protection can be realized, then, carrying out truss-by-truss arch replacement construction on the primary support structure with large deformation limit, namely, firstly dismantling truss deformation support, then timely erecting temporary support and pouring new support structure, and sequentially and circularly advancing. The method has the fatal defects that on one hand, the primary spraying and sealing cannot solve the sliding risk of surrounding rocks in a cavity, the disturbance to the surrounding rocks in the process of changing the arch can cause secondary collapse of loose rock bodies in the cavity, the collapse probability is high, on the other hand, the supporting structures are removed one by one, the stress of local surrounding rocks is released instantaneously, the stress release rate can reach 0.5MPa/h, the self-stabilization capability of the surrounding rocks is far exceeded, the chain collapse is extremely easy to cause the casualties of construction personnel and the damage of construction equipment, meanwhile, the arch changing construction period is long, and only 1-2 supporting and changing can be completed in a single cycle, so that the integral construction progress of a tunnel is seriously influenced. Therefore, a construction method for the collapse area of the weak surrounding rock tunnel is needed to be matched with supporting equipment, so that the construction risk is reduced fundamentally, the treatment efficiency is improved, and the safe construction of the collapse area of the tunnel construction is facilitated. Disclosure of Invention The invention mainly aims to provide a construction method and supporting equipment for a collapse area of a weak surrounding rock tunnel, and solves the problems that the existing weak surrounding rock tunnel collapses, a vault cavity and primary support are difficult to dispose when being deformed greatly, and construction safety risks are high. In order to solve the technical problems, the invention adopts the following technical scheme: a construction method of a weak surrounding rock tunnel collapse area comprises the following steps: S1, after the tunnel collapses, backfilling back pressure is carried out on the cavity collapse area to form a stable slope body; performing closed reinforcement construction on the slope by spraying concrete to form a closed surface; s2, constructing a bracket in a tunnel collapse deformation limit area to finish supporting; S3, expanding and digging one end of the tunnel collapse deformation limit area, which is far away from the sealing surface; S4, constructing a pipe shed working chamber and constructing a guide wall; S5, constructing an advance pipe shed at the guide wall, and grouting the advance pipe shed; S6, after grouting construction is completed and the design strength is reached, excavating and supporting construction are carried out on the cavity area of the tunnel, and the length of the supporting section reaches the tail end of the pipe shed; S7, the construction of the collapse section is completed, the support is removed, and the tunnel construction is continued. In the preferred scheme, in S3 and S4, the expanding and digging areas are the top end and the side edge of the tunnel, the expanding and digging areas form a tunnel face, and the guide wall is arranged at the tunnel face; The length of the digging section is required to ensure that the construction of the advance