Study On Large Deformation Mechanism And Prevention Technique Of The Wall Rock In Gong He Tunnel

With the rapid development of China's infrastructure and promoting the further development of the western region, the rapid development of railway, Highway and underground Project,a lot of long and deep tunnel are starting. The soft rock and high stress areas across the body, often leads to large deformation of soft rock related to geological disasters. Peripheral rock large deformation is a kind of great hazardous geology casualty of underground engineering. By now, the Gong He Tunnel has happened several times large deformation hazards. Cognition the mechanism of large deformation and taking effective control measurements is very important to assure the smoothly construction of Gong He Tunnel.The dissertation detailed explains the engineering geology conditions of Gong He Tunnel area. According to mounts of site tracing investigations, author has researched the formation mechanism of wall rocks at Gong He Tunnel. On the base of engineer geology analysis, applying the modern support theory and construction conception of underground engineer, and combining with modern monitor technique and numerical simulation, has researched and discussed about support, forecast and information design-construct etc. three phase on large deformation'prevention.Obtain these chief research achievements:(1) According to tracing research of tunnel peripheral rock deformation and fracture characteristic, profoundly research about Gong He tunnel peripheral rock large deformation's formation mechanism and model. According to the controlling conditions, great wall rock distortion is divided into two big types of wall rock lithology controlling type and rock structure controlling type.(2) Based on wall rock geology analysis, by the means of numerical simulation analysis of supporting structure mechanism by Abaqus and wall rock supporting effect inspection, the thesis presents a thought of wall rock supporting countermeasures of tunnel construction.(3) Through the supporting mechanism research of Gong He tunnel, the supporting countermeasures of great wall rock distortion like anchorage bar, bar mat spraying concrete and the combination of steel arch and leading shed obtain good effects.(4) Through numerical simulation, supporting inspection and engineering practices, enhancing the toughness of supporting structures can prevent the great wall rock distortion like Gong He tunnel experienced.(5) On theoretical to explain several predicted basic problem, establish a suite of much completely predictive technical system of large deformation, through specific application to canonical fragment, certificate that applicability and validity of this predictive system.