Abstract：East passageway of Xiamen subsea tunnel is a huge sea-crossing project. It is a significant route connecting Xiamen island with Xiang¢an city. Furthermore，it is the first large cross-section subsea tunnel in China，which is constructed with drill and blasting method. The construction will go through the most unfavorable strata and the most difficult construction was found in the latter half year of 2007. The CRD method is used to excavate the weathered slot. The mechanical behaviors and deformational characteristics of the supporting structures and host rock during the tunnel excavation are highly focused on recently. From the characteristics of the excavation，based on the hydro-mechanical coupling theory，the CRD construction process in the weathered slot is simulated with finite element software ABAQUS. The distributions of stresses，external water pressures and displacements in the host rock，the distributions of stresses in the supporting structures，the external water pressures of initial lining during the CRD construction process are analyzed. The obtained results from the research work are useful for the tunnel construction，and it will provide references to other projects in practice
