Reliability analysis of shallow-buried tunnel construction adjacent to karst cave

In this paper, based on the upper-bound theorem of limit analysis and the reliability theory, the reliability performance function of the rock and soil mass around the tunnel and the karst cave should be constructed. Through Matlab software programming, the instability probability and reliability index of the rock and soil mass around the tunnel and the karst cave are calculated by applying the Monte Carlo method. Applying the method to practical engineering, the reliability of the rock and soil in each damage zone in the karst area is studied. The study shows that when the ratio of tunnel buried depth to tunnel diameter is greater than 2, the tunnel passes through the moderately weathered dolomite layer or the slightly weathered dolomite layer, the self-supporting capacity of the rock and soil mass in front of the tunnel face has been significantly enhanced. The stability of the rock and soil mass around the left side of the karst cave has been significantly enhanced when the ratio of the clear distance between the cave and the bottom of the tunnel to cave diameter is greater than 2.