Elasto-plastic analysis on surrounding rock mass under non-uniform stress field

According to the deformation characteristics of rock material,introduced some parameters which in practical projects for surrounding rock has certain influence,using rocks stress-strain three lines mechanical model,mechanical behaviors of the non-uniform stress field of circular tunnels elastic zone,plastic-softening zone,plastic-residual zone were analyzed,and the non-uniform stress field of circular tunnels elasto-plastic theoretical solution was deduced.Based on a concrete example gave,analyzed different affecting factors on the influence of the surrounding rock.Through examples show that the side pressure coefficient,strain softening,supporting pressure of the rock have large effect on surrounding rock mechanics behaviors and plastic zone.Along with the increase of side pressure coefficient,two sides roadway in plastic zone range decreases;softening modulus of lower can reduce the radius of plastic zone;supporting pressure increases can also reduce the plastic zone radius.Understand the rock side pressure coefficient,the control of rock softening modulus,timely increase supporting pressure can effectively control the stability of surrounding rock.