Abstract:Based on the comprehensive testing system for structure and surrounding rockmasses of highway tunnel (CTSSSRH),taking Chaodongyan Tunnel as an example,a test concerning the influence of karst cave size on stability of surrounding rockmasses during tunnel construction is carried out through physical and numerical modeling. The ANSYS software is used for 3D elastic-plastic FE analysis,and the yield initiation is assumed to occur following Druck-Prager failure criterion. The results of physical model testing and numerical analysis show that the deformation of surrounding rockmasses of tunnel varies with increase of the karst cave size. The excavation of tunnel with karst caves will amplify the deformation of the surrounding rockmasses of tunnel without karst caves.