摘要
///In this paper,after the stress analysis of surrounding rocks,excavation simulated experiments and numerical calculation are applied to study the characteristics of arching action under conditions of different rock properties.Firstly,inner boundary and thickness are used to define an arch in surrounding rocks and to evaluate the stability of underground openings.Then,the arching action is defined in the excavation simulated experiment.In numerical analysis,it is found that joints have great influence on the formation of an arch.The position of inner boundary of pressure arch is far away from an opening and thickness is greater with the decrease of joint space.And,in rock mass containing two sets of joint,when a joint incline angle is 30 degree or 60 degree respectively,it is disadvantageous for an arch formation.