Study on the Evolution Simulation of Mining-induced Stress Field and Its Testing System
Author:Zhu Zhu Wu
Supervisor:shi yong kui
Mining-induced stress and its development evolution caused by the coalface advancing and roadway drivage is the root source of mine dynamic disaster accidents of roof,gas,rockburst,or mine water.So,acquiring the knowledge of the overlying strata movement and development law,mining-induced stress field evolution,and the relationship of mining-induced stress development process and relevant dynamic disaster accidents under different mining conditions,is the basis for realizing mine safe and high-efficient exploitation,is also one of the keys of theoretical development of mining engineering discipline.The main research results in this dissertation are as followed.(1)Mining-’induced stress and failure characteristics of coal have great effect on o verburden structure,after the excavation of working face and under the influence of mining induced stress,the stress concentration degree is Hard-Hard>Hard-Soft>Soft-Hard>Soft-Soft.Meanwhile,under the influence of mining induced stress,and coal d eformation can be divided into three stages:elastic stage,coal damage stage and stab le stage,the deformation degree sequence is Soft-Soft>Soft-Hard>Hard-Soft>Hard-Hard.(2)This dissertation developed mining-induced stress testing system,which includes stress loading system,hydraulic serve control system,computer-control system and acoustic emission monitoring system,and its The operation model and algorithm.(3)Solidworks is adoped to test the system’s reliability both from the loading system’s static stress and fatigue analysis,which ensures the test system can be used to study the damage characteristics of coal and rock under stress transfer.(4)By using this invented testing machine,this paper studied damage mechanical properties of large-size rock specimens and its acoustic emission characteristics,and obtained the effects of the external damaged coal or rock on the bearing capacity of the inner coal or rock,the effects of different horizontal stress,vertical stress and stress-transferring speed on the bearing capacity of rock or coal mass and the degree of damage in different zone of coal or rock mass.The research results and the invented testing system in this dissertation will provide more scientific and quantitative method for predicting and controlling mine dynamic disaster accidents,which lays the foundation of realizing mine safety production decision,mine informatization,intellectualization and visualization.The research results will promote the further development of practical mine pressure theory.