the construction scheme of Xiamen subsea tunnel is optimized. Under conditions that lateral pressure coefficients equal to 0.6 and 0.9
firstly three common construction methods that are method of whole section excavation
scheme of upper and down benching and bench tunneling method are analyzed; the result that method of whole section excavation will slightly disturb the surrounding rock is gained compared the displacements of keypoints and the distributions of plastic zone on the surface of wall rock; finally the conclusion that the reasonable bench pace between upper and down benches is around 10 meters is proposed by analyzing tunnel stability under different bench lengths. The conclusion can direct the construction of tunnel better.