Tunnel flexible ring type supporting system suitable for passing through movable fault zone

Abstract

The invention discloses a tunnel flexible ring type supporting system suitable for passing through a movable fault zone. The tunnel flexible ring type supporting system is characterized in that a surrounding rock grouting reinforcement layer, a primary support layer, an anchor net layer, a steel bar row, a first annular steel arch, a rubber cushioning layer, a second annular steel arch, supportingoil cylinders, a third annular steel arch, a rubber particle filling layer and a prefabricated steel pipe tunnel. The primary support layer achieves excavation forming on the section of the channel,after the procedure of grouting reinforcement is completed, pavement of ribbed steel bars and injection of concrete are carried out along the annular outline of tunnel surrounding rock, and after maintenance is finished, construction of the primary support layer is completed; the anchor net layer fixes a dense-hole steel bar net onto the primary support layer through anchor rods; the steel bar rowis paved on the anchor net layer in the axial direction of the tunnel; and the multiple supporting oil cylinders are distributed in the axial direction and the radial direction of the tunnel in an array manner.

Description

technical field [0001] The invention relates to a tunnel flexible ring support system suitable for crossing active fault zones. Background technique [0002] The statements herein merely provide background information related to the present invention and do not necessarily constitute prior art. [0003] With the advancement of the western development and construction, more and more tunnels in my country are faced with the construction task of crossing active fault zones, especially for tunnels crossing active fault fracture zones, which are subjected to fault fracture rock mass pressure and active fault faults in strong earthquakes. Due to the effect of dislocation, the tunnel will experience earthquake damage such as lining cracking, dislocation, and even overall collapse. For example, in the 1978 Izu Oshima earthquake of magnitude 7.0 in Japan, the 906m-long single-track Inatori tunnel was severely damaged because it crossed the Omine Mountain fault. A bulge of about 0.5m o...

AI Technical Summary

Problems solved by technology

[0004] The longitudinally variable structure mainly reduces the non-uniform longitudinal deformation of the tunnel caused by faults by setting a certain number of flexible joints or damping joints along the longitudinal direction of the tunnel, and improves the adaptive deformation capacity of the tunnel, thereby reducing the effect of fault dislocation in the axial shear of the tunnel. However, local shearing, extrusion and tensile damage may occur at the flexible joints and damping joints in the tunnel. On the one hand, it is difficult to ensure the waterproof function of the tunnel; , the longitudinally variable structure is difficult to provide sufficient overall bearing capacity of the tunnel

[0005] The horizontal expansion excavation structure mainly adopts cross-section expansion in the fault dislocation section of the tunnel to reserve the fault dislocation amount and absorb the fault dislocation displacement, but the section expansion increases the construction economic cost and also weakens the self-bearing capacity of the surrounding rock , under the action of active fault shearing and extrusion, it may cause rock mass instability in the broken zone, resulting in the tunnel being unable to withstand the rock mass instability pressure in the broken zone, resulting in serious earthquake damage such as overall collapse and water gushing

[0006] The inventor found that so far, some tunnels in my country have completed the construction task of tunnels crossing active fault zones by applying the above method. However, these tunnels have a relatively simple structure and cannot effectively resist the strong shear stress and tension and compression caused by fault dislocation. Stress, leading to many problems such as inverted arch bulge or collapse of the tunnel, peeling off of the second lining, failure of the waterproof layer after the occurrence of fault activities, resulting in the failure of the normal operation of the tunnel.

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