Study On Construction Monitoring Technology Of Langya Mountain Tunnel In Chu Huai Expressway

In this paper, with the tunnel from Chuzhou to Dingyuan in Chu-Huai highway of Anhui province as a support project, a reasonable monitoring and measuring programs and the implementation details are determined according to the engineering geological conditions of Langya mountain tunnel. By analyzing the monitoring data of Langya mountain tunnel, the velocity and the change trend of surrounding rock displacement are obtained, and the final displacement value of the surrounding rock is predicted based on linear regression analysis. The excavation of soft surrounding rock tunnel is numerically simulated by means of FLAC3D software, then the simulation results are compared with the actual data of field monitoring, and the changing laws of the tunnel surrounding rock strain and stress are acquired. On the basis of such works and a combination of the domestic and foreign data, the surrounding rock change management level has been established. In the end, the conclusions are summarized as follows:â‘ Tunnel surface subsidence are closely related with the engineering geological conditions and construction methods. Reducing the excavation of the surrounding rock disturbance can effectively decrease the surface subsidence;â‘¡Due to the impact of the construction method, when the next step are excavated, surrounding convergence and vault settlement will accelerate the emergence of the phenomenon of deformed again, but found less affected by the construction site excavation invert to deformation, initial support Upon completion of the surrounding rock deformation rate gradually approaches zero, and ultimately reach a steady state;â‘¢When the surrounding convergence of the tunnel or the crown settlement rate reaches or exceeds 10mm/d, it is necessary to strengthen the measures to control the deformation in time to prevent the structural damage;â‘£During the excavation and support of CD method, the main parts of the surrounding rock stress concentration are mainly distributed in the side wall and arch foot, special reinforcement treatments should be carried out on these parts in construction to prevent structural damage.