Back-Analysis for Surrounding Rock Deformation Monitoring of Yunling Tunnel

Taking into account of complicated geological environment, large deformation, high stress and long-time use, stability analysis for surrounding rock is very important for the deep, long and wide tunnel engineering. Defining parameters by displacement back analysis has been the focus of current study. This method can be used to deal with the complicated non-linear relationship between the parameters of surrounding rock and the measuring information, and to judge and adjust the scheme of second support, while artificial Intelligence are adept in identification, representation and management of the non-linear relationship. The paper, through deformation monitoring for surrounding rock of Yunling tunnel of Shi-Man highway, combined the system of biologic emulation and the software of fast lagrangian analysis of continua (FLAC) to conduct direct analysis, took the advantage of the high nonlinearity, good reasoning and integration of neural network and obtained output vector by data-analysis software. Then we took adaptive immunity algorithm as searching tool to look for the best network structure for parameters in all room, searched for the best parameters with back analysis according information gained by measuring practically. Finally, direct calculation came out the results. This back analysis, improved the primary parameters of physical and mechanical parameters of tunnel surrounding rock, adjusted the scheme of support and obtained satisfied conclusion. The research results show that the back analysis proposed in this paper is of practical significance to the stability analysis of the tunnel surrounding rock and to informational design.