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CN-122014280-A - Supporting structure and supporting method for tunnel to pass through fault fracture zone

CN122014280ACN 122014280 ACN122014280 ACN 122014280ACN-122014280-A

Abstract

The invention provides a supporting structure and a supporting method for a tunnel to pass through a fault fracture zone, wherein the supporting structure comprises an undeployed hole section and a caving zone hole section, which are arranged on the front edge of a caving zone along the trend of the tunnel, the supporting structure in the caving zone hole section is connected with pipe piles and comprises a permanent lining structure arranged on the inner side of the supporting structure, the permanent lining structure is in a shell shape similar to the inner wall of the tunnel, a plurality of pipe piles are arranged at intervals along the circumference of the caving zone, the longitudinal length of the pipe piles covers the longitudinal range of the whole caving zone, one end of each pipe pile is supported in the undeployed hole section, the other end of each pipe pile is supported in a stable rock body behind the caving zone, the pipe piles are fixedly combined into an integral structure through grouting and peripheral loose caving bodies, and pile body components are arranged in the pipe piles. The invention ensures the safe crossing of the collapse area, solves the technical problem of poor self-stabilizing capability of the collapse area of the large fault, and reduces the construction risk.

Inventors

  • ZHU ANLONG
  • YANG HAO

Assignees

  • 中国电建集团华东勘测设计研究院有限公司

Dates

Publication Date
20260512
Application Date
20260106

Claims (9)

  1. 1. A supporting construction for tunnel passes through fault fracture area, its characterized in that includes: The support reinforcing structure is arranged in an undeployed hole section at the front edge of the collapse zone and in the collapse zone hole section along the trend of the tunnel, is connected with the pipe pile and comprises a permanent lining structure arranged at the inner side of the support reinforcing structure, and the permanent lining structure is in a shell shape similar to the inner wall of the tunnel; The pile piles are arranged at intervals along the circumference of the cave in the collapse zone, the longitudinal length of the pile piles covers the longitudinal range of the whole collapse zone, one end of each pile is supported in the non-collapse cave section, and the other end of each pile is supported in the stable rock body behind the collapse zone; and the pile body component is arranged inside the tubular pile.
  2. 2. The supporting structure for tunnel crossing fault fracture zones according to claim 1, wherein a non-collapse zone arch is arranged in an undeployed hole section of the front edge of the collapse zone, the non-collapse zone arch is connected with a tunnel wall through anchor rod supporting and reinforcing anchor rods, and net sprayed concrete is hung on the inner wall of the non-collapse zone hole section.
  3. 3. The supporting structure for tunnel crossing fault fracture zone according to claim 1, wherein the tubular pile comprises a following steel pipe with a plurality of grouting holes on the wall of the following steel pipe, the surface of the following steel pipe is fixedly connected with a loose collapse body, and the pile body component is arranged in the following steel pipe.
  4. 4. The supporting structure for a tunnel crossing fault fracture zone according to claim 1, wherein the pile body component comprises a seamless steel pipe and a tendon arranged in the seamless steel pipe, the tendon is composed of a plurality of steel bars, two ends of the tendon are correspondingly fixed with two ends of the seamless steel pipe, and the ends of the seamless steel pipe are arranged in a closed mode and are internally filled with cement mortar.
  5. 5. The supporting structure for tunnel crossing fault fracture zone according to claim 4, wherein a plurality of positioning support members are welded at intervals along the axial direction of the outside of the tendon, the positioning support members have an outer contour matched with the inner wall of the seamless steel pipe and an inner contour matched with the tendon, and the tendon is positioned at a set position in the seamless steel pipe by the positioning support members.
  6. 6. The supporting structure for tunnel crossing fault fracture zones according to claim 1, wherein a plurality of rows of collapse zone arches and auxiliary arches are arranged in the collapse zone tunnel sections, the collapse zone arches are connected with the pipe piles through the auxiliary arches, and the permanent lining structures are arranged on the inner sides of the plurality of rows of collapse zone arches.
  7. 7. The supporting structure for tunnel crossing fault fracture zone according to claim 1, wherein backfill pumping concrete pipes are arranged on the permanent lining structure, and backfill concrete is filled in cavities above top arches of the supporting and reinforcing structure in the collapse zone section.
  8. 8. The support structure for a tunnel crossing fault fracture zone according to claim 1, wherein the exposed face roof arch in the collapsed region is provided with a lead support.
  9. 9. A method for supporting a tunnel through a fault fracture zone, characterized by using the supporting structure of claims 1-8 to support, dividing the supporting structure into a plurality of stages of buildings, and comprising the following steps: S1, maintaining a stacking state formed by collapse of the front part of a tunnel face when the excavated tunnel collapses, and forming an operation platform by utilizing the stacked collapse; S2, constructing an arch frame of a non-collapse area in a set hole section of which the front edge of the collapse area is not collapsed, and combining with system anchor spraying support for combined reinforcement to form a primary support reinforcement structure; s3, drilling holes through the collapse area by adopting a pipe-following drilling process, and reserving the pipe-following steel pipe as a permanent support and grouting channel after the drilling holes are completed, wherein one end of the pipe-following steel pipe is supported in a set hole section of a primary support reinforcing structure, and the other end of the pipe-following steel pipe is supported on a stable rock body behind the collapse area; s4, carrying out construction of a next-stage supporting and reinforcing structure in a hole section of the collapse area after the tubular pile construction is completed, carrying out local grouting on lower slag bodies in the hole section of the collapse area in the construction process of the new-stage supporting and reinforcing structure to form a first-stage slag body consolidation grouting section with a temporary stabilization effect, carrying out local excavation on the first-stage slag body consolidation grouting section, and erecting an arch frame and a secondary arch of the collapse area in time in the hole section within the range of the first-stage slag body consolidation grouting section after the excavation; s5, repeating the construction process of the step S4, and sequentially applying the support reinforcing structures of the subsequent stages on the basis of the support reinforcing structures of the previous stage until the support reinforcing structures pass through the cave sections of the collapse areas; S6, after all slag bodies in the collapse area are cleared, performing advanced support on the exposed tunnel face top arch, and performing final trimming on the tunnel face under the protection of the advanced support; And S7, after traversing the collapse section, combining the overall construction requirement, constructing a permanent lining structure, reserving a backfill concrete pumping pipe on the permanent lining structure, and after the construction of the permanent lining structure is finished, performing pumping concrete backfill of a cavity between the permanent lining structure and the pipe pile.

Description

Supporting structure and supporting method for tunnel to pass through fault fracture zone Technical Field The invention relates to the technical field of tunnel engineering, in particular to a supporting structure and a supporting method for a tunnel to pass through a fault fracture zone. Background Collapse is a common phenomenon in the process of tunnel excavation by adopting a drilling and blasting method, and is one of main risks endangering the safety of constructors. When the tunnel passes through a large fault, if filling materials in the fault zone are loose, especially under the condition of a steep dip angle large fault, the situation that a collapse area cannot be self-stabilized is very easy to occur. As the soil mass in the collapse area is changed from the original relatively tight filling state to the loose accumulation state, the volume of the soil mass in the collapse area is correspondingly increased. Therefore, the collapse range is not generally extended infinitely without disturbing the post-collapse state. However, if the collapse area is cleaned, the collapse range is more likely to be expanded, even roof collapse accidents are caused, and construction safety is seriously threatened. In conventional pipe shed traversing embodiments, the pipe shed is not a freestanding support structure, but rather forms a monolithic arch effect by consolidation with surrounding rock mass. Therefore, the implementation effect of the scheme is closely related to grouting quality. The grouting quality control difficulty of the pipe shed is high in the face of large-scale fault collapse. On one hand, the slurry gap connectivity is good, if the grouting amount is controlled improperly, the cavity is easy to appear in the pipe shed, and the pipe shed is likely to be broken in the excavation process, on the other hand, if the grouting pressure is increased to ensure the slurry filling effect in the pipe shed, the slurry stringing problem is easy to occur, the treatment effect is poor, and the treatment cost is also obviously increased. Disclosure of Invention In view of the shortcomings in the prior art, a first object of the present invention is to provide a support structure for a tunnel passing through a fault zone. The invention ensures the safe crossing of the collapse area, solves the technical problem of poor self-stabilizing capability of the collapse area of the large fault, and reduces the construction risk. In a first aspect, the present invention provides a support structure for a tunnel crossing fault fracture zone, comprising: The support reinforcing structure is arranged in an undeployed hole section at the front edge of the collapse zone and in the collapse zone hole section along the trend of the tunnel, is connected with the pipe pile and comprises a permanent lining structure arranged at the inner side of the support reinforcing structure; The pile piles are arranged at intervals along the circumference of the cave in the collapse zone, the longitudinal length of the pile piles covers the longitudinal range of the whole collapse zone, one end of each pile is supported in the non-collapse cave section, and the other end of each pile is supported in the stable rock body behind the collapse zone; and the pile body component is arranged inside the tubular pile. As a preferable technical scheme of the invention, a non-collapse area arch frame is arranged in an undeployed hole section at the front edge of the collapse area, the non-collapse area arch frame is connected with a hole wall through an anchor bolt support and a reinforcing anchor bolt, and net spraying concrete is hung on the inner wall of the undeployed hole section. According to the preferable technical scheme, the tubular pile comprises a steel pipe with a plurality of grouting holes on the hole wall, the surface of the steel pipe is fixedly connected with a loose collapse body, and the pile body component is arranged in the steel pipe. According to the invention, the pile body part comprises a seamless steel pipe and a tendon arranged in the seamless steel pipe, wherein the tendon consists of a plurality of steel bars, two ends of the tendon are correspondingly fixed with two ends of the seamless steel pipe, and the ends of the seamless steel pipe are closed and filled with cement mortar. The technical scheme is that a plurality of positioning support pieces are welded on the outer side of the steel bar bundles at intervals along the axial direction of the steel bar bundles, each positioning support piece is provided with an outer contour matched with the inner wall of the seamless steel tube and an inner contour matched with a steel bar, and the steel bar is positioned at a set position in the seamless steel tube through the positioning support piece. As a preferable technical scheme of the invention, a plurality of rows of collapse area arches and auxiliary arches are arranged in the collapse area hole section, the collapse area