Research on Optimization of Tunnel Cyclic Advance Rate Based on Ubiquitous Joint Model
(1 Institute of Road and Bridge Engineering, Dalian Maritime University, Dalian 116026; 2 Jilin Traffic Planning and Design Institute,Changchun 130021)
Abstract:
In order to determine the reasonable cycle advance rate of the highway tunnel in rock with developed joints, the distribution laws of peripheral displacements, stresses and plastic zones are simulated and analyzed under the advance rates of 0.5 m, 1.0 m, 1.5 m and 2.0 m based on ubiquitous joint model by taking the No. 2 Zhenfengling tunnel in Jilin Province as the background. The research results show that the peripheral displacement,stress and plastic zone are positively correlated with the advance rate and the uprush occurs when under the advance rate of 2.0 m; based on a comparison and analysis of the numerical simulation results under the four working conditions, it is considered that the cyclic advance rate of the tunnel in jointed rock mass should be 1.5 m under action of shotcreting and anchoring; the numerical simulation results of the tunnel in jointed rock mass based on ubiquitous joint model agree well with the on-site monitoring results, verifying the rationality of the 1.5 m advance rate.