Abstract:

Taking Wuchiba tunnel as the engineering background, a three-dimensional geological model of tunnels in karst regions was established. Characteristics of rock stress around the tunnel in the direction of tunnel axes and vertical tunnel direction of the axes  were analyzed, based on the conditions of fuid-solid coupling. Relations of the stress around the tunnel and the distance between the cross sections and the underground river, and the surface karst depressions as well as the relationship between working conditions were discussed. Displacement variation of a typical crosssection under a variety of working conditions of the tunnel wall was analyzed. Water inflow to the tunnel was analyzed and forecasted by means of the finite element method. The obtained results can provide references for the analysis of rock mass stability and prediction of water inflow of tunnels in karst zones.

Key words: expressway, tunnel in karst zone, stability of rock mass, water inflow forecast, fluid-solid coupling