Numerical Study of TBM Excavated Coal Mine Roadway Support Design

Abstract

In TBM excavation projects of Zhangji coal mine which is the first application of TBM at deep underground coal mine, computational modelling was conducted in surrounding rock stability study and support design of coal mine TBM excavated roadway due to lack of experience in similar projects. This paper presents a support design methodology of TBM excavated roadway at deep underground coal mine. A three-dimension finite element model was established, and the non-uniform tectonic stress filed was also been simulated in the model. Stress redistribution, displacement and plastic zone range of surrounding rock under different support patterns were analyzed and support design of the roadway was made on the base of simulation results. During roadway excavation, instrument rock bolts were installed for monitoring stress distribution and roadway convergence. The monitoring results suggest that computational simulation results correspond with in-situ monitoring data, horizontal stress concentrates on the roof and floor of roadway and vertical stress concentrates on lateral sides. The roadway convergence increased significantly after excavation and then slowed down and finally stopped after 40 days.