According to reference [1]

calculation parameters of strain-hardening elastoplastic model in the strongly weathered granite region are obtained by back analysis. The CRD method

double-side-drift method and bench method are used to study the deformation behavior of the surrounding rock and support structure by the numerical simulation respectively. It is shown that the CRD method is the best method for undersea tunnel excavation after comparing the results. On this basis

considering the in-situ situation of section ZK8+257-ZK8 +307 of Xiamen undersea tunnel

a 3D numerical model is established to simulate the tunnel excavation process constructed by CRD method. Meanwhile

a comparative analysis between the calculation results and in-situ measurements is carried out. The results show that the numerical simulation technology as well as the strain-hardening elastoplastic model established here can well reflect the deformation behavior and damage rule of strongly weathered granite during Xiamen undersea tunnel excavation. The results can provide guidance for lining design

support technology and also tunnel construction for the same kind of tunnel construction.