BQ Surrounding Rock Classification And Stability Analysis In Fengshan Tunnel

Fengshan tunnel which connecting Xiaoxian county seat and the high-speed rail station is a crucial project, the smooth opening of the tunnel will inject new impetus into the economic and social development of Xiaoxian. The transverse cooperation project “The construction safety monitoring and surrounding rock grades real-time discrimination in Fengshan tunnel” as the research background. In view of the short surveying period in Fengshan tunnel, limited number of measuring holes can not get detailed geological information and excavation has been found the surrounding rock classification does not match the actual level in the early stage, therefore, the surrounding rock classification and stability are analyzed and studied in the tunnel construction process. The BQ classification method is used as the main basis for the surrounding rock identification in Fengshan tunnel. The classification method is studied in detail, which is conducive to the optimization of surrounding rock classification index. The stability of surrounding rock is further studied by the field monitoring measurement and the calculation of elastic plastic model. The main research work and achievements are as follows:(1) The resilience value is introduced into the quantitative indicators of surrounding rock classification. Based on the field data collection and laboratory test, the relationship between the rebound value and the uniaxial saturated compressive strength value is obtained.(2) Through applying BQ surrounding rock classification, collecting tunnel face of qualitative and quantitative indices, close to the actual results are obtained in Fengshan tunnel.(3) Applying rock deformation monitoring, deformation law of tunnel can be obtained from typical section of different surrounding rock level monitoring result. It can be used in stability analysis of surrounding rock and determining surrounding rock stability monitoring management standard.(4) The elastic-plastic calculation model of tunnel is established. The calculation parameters are selected according to the geological prospecting data and relevant specifications. By using different calculation methods, the basically coincident results of the radius of plastic zone are obtained. So this method is applicable to the theoretical analysis of typical section in Fengshan tunnel.