Numerical Simulation on the Surrounding Rock Large Deformation and Support Structure of Youshui Tunnel

The Youshui tunnel is located at Xihan expressway in Shaanxi province and the surrounding rock large deformation had taken place in many places.The monitoring data show that the deformation occurred rapidly and in long duration.The maximum cumulative vertical and horizontal displacements reached 60cm and 50cm.In order to seek rational primary supporting structure,the non-supporting excavating is simulated by using numerical simulation.The reasons of surrounding rock large deformation failure are mastered.The original primary support design and the secondary variation design are simulated by using shell elements.The limitation of the original design and the rationality of the secondary variation design are proved up.The unsubstantial regions of the primary support are discovered.The optimal designs are put forward based on the results of simulation.The results of simulation can be as a reference for the similar large deformation surrounding rock in tunnels and underground engineering.