Experimental Study on the Pattern of Surrounding Rocks’ Movement under Excavation Activities and Impact Prevention Technologies in Island Mining Face

Abstract

Based on the structural feature of island mining face’s ‘T’ shape overburden and by using analog material and numerical simulation to analyze the rules of overburden movement and stress distribution, and yield failure characteristics during stoping in island mining face, this paper studies the variation rules of roadway stress, acceleration, displacement and deformation velocity when island mining face’s overburden breaks, producing strong dynamic impact load. The result shows: In the beginning stage of stoping, plastic failure in the surrounding rocks mainly appears in the roof, while in later times, plastic failure in the overburden will gradually move up towards the overlying strata, appearing in symmetrical arcuate; under the dynamic load of mine earthquakes, the left and right ribs suffer slighter deformation than the roof and the floor; the right rib and the roof changes faster than other places; the roof sinks the most; and the vertical stress on the left and right ribs are bigger than that on the roof and the floor. The rules of overburden movement and impact failure in island mining face stated in this paper provide theories for impact prevention in high impact-risk island mining face, impact prevention parameters design and impact prevention measure-making as well as help engineering practice so as to guarantee stoping safety in high impact-risk island mining face.