Abstract: Problems of multi-body contact with seepage are common in hydraulic engineering, but traditional joint element-based methods have a number of shortcomings. In this paper, we develop a new algorithm of multi-body contact with consolidation using a Lagrange multiplier method to handle the pore pressure continuity condition at contact interfaces, based on the computational contact mechanics and fluid-solid coupling. This algorithm is applied to a stress-deformation analysis of the observation galleries in the earth core of the Rumei dam. Numerical calculations show that it is capable of handling non-conforming meshes and effectively solves the enormous difficulties in mesh generation arising from the complicated 3D form of the galleries and the huge dimensional differences between the gallery blocks and dam body. The calculated gallery displacements are reasonable, and the behaviors of discontinuous deformation such as the separation and sliding between the gallery blocks are captured. By refining the local gallery mesh, we can further achieve better results and a higher accuracy in the calculations of stress distribution over the gallery blocks.

Key words: computational contact mechanics, fluid-solid coupling, Rumei earth-rockfill dam, observation gallery