Integral support system and construction method of rock pillar in double-hole tunnel

Abstract

Provided are an integral support system and a construction method of a rock pillar in a double-hole tunnel. Upper grouting bolts are anchored on left and right sides of the upper portion of the rock pillar in the tunnel, a horizontal pre-stress grouting bolt is horizontally anchored and penetrates through the middle of the rock pillar in the middle of the tunnel, lower grouting bolts are anchoredon the left and right sides of the lower portion of the rock pillar in the tunnel, the anchor heads of each bolt have appropriate exposed lengths, a plurality of mounting holes adapted to each bolt exposed end are formed in circumferential steel strips and longitudinal steel strips, a plurality of the circumferential steel strips are circumferentially arranged along the inner wall of the tunnel, the mounting holes on the circumferential steel strips respectively tightly sleeve the exposed ends of the corresponding upper grouting bolt, the horizontal pre-stress grouting bolt or the lower grouting bolt, a plurality of the longitudinal steel strips are arranged in the axial direction of the tunnel, the mounting holes of the longitudinal steel strips respectively tightly sleeve with the exposed ends of the corresponding bolts, and the exposed ends of the bolts are screwed with locking nuts. The construction method has simple construction process, is easy to operate, and especially has a significant effect on the support of a broken rock body.

Description

technical field [0001] The invention belongs to the technical field of geotechnical engineering, and in particular relates to an integral support system and construction method for rock pillars in a double-hole tunnel. Background technique [0002] With the rapid development of my country's economy, the state has increased investment in road construction, and high-grade roads have gradually extended from plain areas to mountainous areas in the central and western regions. Due to the large span and poor stability of single-hole tunnels, it has brought great difficulties to the construction. Therefore, more and more double-hole tunnels are used at present. There are two structural forms of double-hole tunnels and small clear distance tunnels. The stability mainly depends on the stability of the middle rock pillar, but the poor stability and easy cracking of the middle rock pillar are the main problems that plague the construction of double-hole tunnels. The middle rock column...

AI Technical Summary

Problems solved by technology

Due to the large span and poor stability of single-hole tunnels, it has brought great difficulties to the construction. Therefore, more and more double-hole tunnels are used at present. There are two structural forms of double-hole tunnels and small clear distance tunnels. The stability mainly depends on the stability of the middle rock pillar, but the poor stability and easy cracking of the middle rock pillar are the main problems that plague the construction of double tunnel tunnels

The middle rock column reinforcement technology mainly adopts three reinforcement technologies: small conduit grouting, system bolt, and horizontal through prestressed bolt. The above three are widely accepted, and two or three anchoring methods are generally used in engineering In combination, there are large differences in the surrounding rock support methods even at the same level, which shows that there is no unified theory for medium rock pillar reinforcement technology

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