Deformation reinforcing method of karst cave tunnel initial support

Abstract

The invention discloses a deformation reinforcing method of a karst cave tunnel initial support and relates to the technical field of karst cave tunnel construction. The method comprises following steps: A, setting a plurality of anchor tubes at intervals on two side walls of a tunnel at its initial support deformed segment; B, passing two vertical beams provided with a plurality of through holes through anchor tube ends of the plurality of anchor tubes, and abutting the bottom faces of the vertical beams to outer ends of arch steel beams; C, passing a pad having a central hole through an anchor tube end of each anchor tube so as to abut the pads to the outer ends of the vertical beams, and connecting the arch steel beams with the vertical beams and the vertical beams with the pads. Compared with the prior art, the method enables safe, reliable reinforcement and prevents the deformation of the karst cave tunnel initial support.

Description

technical field [0001] The invention relates to the technical field of karst cave tunnel construction, in particular to a reinforcement method for deformation of primary branches of karst cave tunnels. Background technique [0002] During tunnel construction, it is necessary to carry out initial support for the newly completed tunnel, which is mainly to quickly close the surrounding rock to prevent the surrounding rock from collapsing due to weathering and hydration due to long-term exposure to the influence of water and air; The method of initial support is to set a plurality of arched steel beams made of I-shaped steel at intervals in the tunnel, and on the arched steel beams, there are a plurality of anchor rods extending radially into the rock formation. Shotcrete between steel frames. Due to different geological conditions, complex topography and unfavorable geological conditions such as karst caves or filled karst caves, fault fracture zones, and weak interlayers are ...

AI Technical Summary

Problems solved by technology

Due to different geological conditions, complex topography and unfavorable geological conditions such as karst caves or filled karst caves, fault fracture zones, and weak interlayers are often encountered; due to the low strength, complex structure, and poor stability of such surrounding rocks, it is easy to Softening and inward extrusion can easily cause deformation of the primary support of the tunnel, internal extrusion, and even landslides, and there is a great safety risk; at present, a reinforcement method for this initial support of the tunnel is to use radial anchor rods to inject Slurry support reinforcement

Since this reinforcement method is realized through the bonding force between the cement mortar around the bolt and the surrounding rock, the main function of the bolt is to strengthen the surrounding rock by forming a "reinforcement ring" of a certain thickness, and the load transmitted from the outer layer It is mainly borne by the "reinforcement ring", which has a certain effect on improving the stability of the surrounding rock; however, the supporting effect of the bolt on the soft rock with large deformation and large plasticity cannot be guaranteed, and because the length of the bolt is short, the longest The length of the tunnel is only 5 meters, and it is impossible to pass through some geological structures such as loose clay and rocks to be anchored into stable rock formations, and the stability of the surrounding rock of the tunnel cannot be effectively controlled. Therefore, when the initial support of the tunnel is deformed due to compression and reinforcement fails happened

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