Study on Bolt Support Design for Carbonaceous Shale Tunnel of Highway at High Altitude and Cold Region

Abstract

With the large-scale development of road traffic infrastructure, tunnel construction gradually extends to high-altitude areas such as the Qinghai-Tibet Plateau. Under the influence of environmental and climatic conditions and regional geological tectonic movement, tunnel construction in this area cannot copy the technology and experience of low-altitude areas, and special research work should be carried out in accordance with regional geological characteristics. Based on a tunnel of Gongyu Highway, the bolt support design of high-altitude tunnel is studied by numerical analysis with FLAC3D software. The results show that the arch bolt should be cancelled and the side wall and lock foot bolt should be strengthened in the bolt support of highway tunnel in high-altitude cold area. Then through multi-dimensional comparative analysis, the length, circumferential spacing and setting range of anchor rods in the carbonaceous shale highway tunnel system at high altitude and cold region, as well as the number, direction and length of anchor rods at lock feet are put forward, which provides technical support for the design and construction of the relying projects, and also provides reference for similar projects.