Simulation Experiment Of Surrounding Rock Deformation And Failure Induced By Mining Dynamic Load

With the strength and depth of coal mining in our country rising,rock burst caused by mining dynamic load become more serious.As one of the important research methods in laboratory,physical simulation of dynamic load has been explored and experimented by researchers who usually simulate by charging blasting and neglect the effect and feature of surrounding rock breakage caused by dynamic load.According to this situation,this paper mainly use physical simulation to analyze the deformation and failure of surrounding rock,using throretical analysis,combing with numerical simulation and other research methods to summarize the characteristics of damage induced by dynamic load.The main conclusions are as follows:Based on the rock-burst theory of dynamic-static combined load and similarity thoery,analyze the condition of static and dynamic load..According to the similarity theory,analyze the feature of dynamic and static load and the similarity of dynamic load.The scale factor is compared and whose dimension is analyzed in the MLT system.The experiment is designed and finished basing on the geological conditions of the steeply inclined seam,in which the feature of stress distribution and the effect of surrounding rock caused by dynamic load is explored.The acceleration and displacement when the rock impacting failure has been defined.The results shows that:in the same layer,the stress concentration degree of the left section of the seam floor is highest,and the response characteristics of surrounding rock become more obvious as the load is stronger,the roadway impacted when the simulative energy is 3.92 × 10⁵ J.With the same dynamic load,the response characteristics decayed as the transmission distance became longer.The stress condition became the determinant when the transmission distance was nearly.Another experiment is finished to explore the effect of surrounding rock caused by dynamic load.The results shows that:the stess distribution is symmetrical,the static stress of the left and right sections of roadway roof and floor is the same,while the stress of the medium section is lower.The deformation and failure also become more serious with higer load.With the same load,limited by the dynamic load form of the experiment equipment,the effect caused by the dynamic load is largest of the left section of roadway where occurred the impact when the simulative energy is 9.00×10⁴J,the acceleration and the AE events are more obviously.the effetct of right section is smaller than the left,while that of the top section is smallest.Using FLAC^2D numerical simulation software to comparative study.The results shows that: Reflection and transmissionthe occur and the stress of coal-rock varies as the dynamic load transmits in the medium.The effect of roadway surrounding rock becomes more obviously with higer load and the deformation and failure become more serious.With the same dynamic load,limited by the direction of free space,the response characteristics of the roof and floor are more obviously in the vertical direction,while that of coal wall occur in the horizontal direction,the deformation and failure of the left coal wall are more serious than that of the inner sourrounding rock because of the wave reflection effect.the results are the same as which in the physical simulation,the left section is obviously induced by the dynamic load,and the response characteristics are stronger.The results of numerical and physical simulation are the same.