Investigation on mechanical properties and rock burst tendency of different coal-rock combined bodies

ZUO Jianping; CHEN Yan; CUI Fan

Abstract：Test system MTS 815 was used to carry out uniaxial compression test for Qianjiaying coalrock combined body,and the contrast of strength and deformation behaviors with different combined mode was analyzed.Then,rock burst tendency of different samples and coal-rock interaction were discussed.The results indicate that compared with coal single body strength and elastic modulus of combined body increase and RMR＞RM＞MR.Peak lateral strain of RMR,MR and M have a big difference.However,RM has a small difference.Through uniaxial compression tests of coal single body with the same scale of coal body in coal-rock combined body,it shows that the uniaxial compressive strength of coal single body is lower than combined body.And,compared with coal single body,the increasing rate of strength of combined body is lower.However,compared with rock single body,the decreasing rate of strength of combined is larger.Therefore,coal has a larger influence of the strength of combined body than rock.Pre-peak accumulated energy and post-peak dissipated energy have a proportional relation with uniaxial compressive strength and M＜RM＜MR＜RMR and impact energy index of combined body is larger than coal single body;rock burst tendency increases through the combination.Therefore,to forecast and prevent the occurrence of rock burst in coal mine,it is necessary to identify the rock burst tendency of coal-rock combined body.Experimental results provide a certain theoretical study for coal mining designation and preventation of rock burst of Qianjiaying coal mine.