Abstract：Jiadi tunnel is one of important structures of landscape road－Ouhai road in Wenzhou city. Elongated cut-and-cover tunnel has been designed in entrance for improving environmental design and landscape design. Pile-raft foundation has been introduced based on the characteristic of the entrance design in order to avoid negative effect due to excessive settlement，considering the soft subsoil of portal section. Primary study has been performed on pile raft foundation applied on soft subsoil treatment at tunnel portal based on a 3D FEM model set up for combined action of cut-and-cover tunnel，pile-raft foundation and soil. It¢s indicated by numerical analysis that the applied pile-raft foundation will give the full play of pile bearing capacity and effective control the differential settlement of the cut-and-cover tunnel on the soft subsoil as a result of asymmetric dead load.
