Analysis on the Treatment Technology of Residual Slope Soil, Karst and Unbiased Pressure Tunnel Opening

The upward slope at the entrance of the Lianhuashan Tunnel is relatively steep and biased, and the lower layer of the slope is loose accumulation of soil. The geological conditions are complicated. During the construction of the excavation tunnel, it is easy to slip and collapse in case of rain. There are hidden safety hazards in the construction and operation. The lower part of the tunnel foundation is now gray. Rock and karst; reinforcement by bolt grouting, consolidation and reinforcement by anchor cable frame measures, open tunnel backfi lling and double-row anti-slide pile reinforcement measures to eliminate the infl uence of bias, and double-wall tunneling technology to ensure tunnel entry Safety: The operation safety is ensured by extending the open tunnel, using pile foundation reinforcement measures for the base, and adopting open curtain protection nets for the side slope.