ABSTRACT
The multiple geological planes in tunnel tend to form rock blocks and occur local collapse. This paper proposes a numerical method for block identification and its stability analysis. Use the element reconstruction and node separation method to model multiple geological planes. The contact model considering several contact types is built to simulate the sliding and separation behavior between rock and block. The safety factor of block is calculated based on the strength reduction method. Combined with a tunnel engineering across a fault, the stability of block after excavation is analyzed. The results indicate that, the blocks are loose after excavation, and this method can better consider the influences of the initial geo-stress, excavation unloading, and rock deformation, and it can effectively identify potentially dangerous blocks. This numerical method provides an effective reference for the block stability of tunnel with multiple geological planes.
