Displacements Performance Analysis of Surrounding Rock of Tunnel on High Speed Railway

During construction of tunnel,displacements of surrounding rock are changed along with the excavation of tunnel.According to the location where the displacement occurs,the displacements of surrounding rock of tunnel can be divided into three types,namely,first displacement in front of working face,extrusion displacement of working face and clearance displacement behind working face.These three types of displacements are very critical to the stability controlling of surrounding rocks of tunnel during excavation.Combining Investigations of current domestic and international standards and based on statistics analysis of monitoring data during the tunnel construction of ShiTai Passenger Dedicated Line Railway and LanYu high-speed railway,the controlling baseline of displacement and characteristic of all types of displacement for surrounding rock of Grade Ⅲ~Ⅴ are obtained through research.The displacement on and in front of working face was studied by utilizing FLAC3Dsoftware.The research results obtained in this paper may be used as one of the bases for research of classification of surrounding rock and for classifying the surrounding rock during construction of tunnel.