煤矿动静载组合作用下煤的动力学特性试验研究

As one of the most serious dynamic hazards in deep coal mining, rock burst is showing a sharp increase in number and strength. The dynamic mechanical behavior of coal under dynamic and static combined load is the basic scientific research issue, which is the basic work of revealing the mechanism of rock burst, guidance of rock burst monitoring and prevention. Aiming at revealing the dynamic properties of coal under dynamic and static combined load, in the project the micro-seismic monitoring technology will be firstly applied to study the characters about loading strain rate, intensity, wave groups and etc. of dynamic load by in situ monitoring testing in coal mine. Sequentially, the MTS Landmark 370.50 static and dynamic fatigue test system, coal and rock damage process test systems, high-speed camera system and the microscopic scanning system will be used to experimental study of the relations of coal dynamic properties with the load strain rate, intensity, wave groups and etc. characteristics of mining dynamic load, the law of fracture and damage process and the micro and macro fracture damage electrical and acoustic effects characteristics in the loading test process, in order to establish the constitutive relation of coal under mining dynamic load, reveal the energy accumulation and dissipation laws of coal, the relationship between rock burst tendency property and the mode of dynamic load, the law of microscopic and macroscopic damage and fracture, the law of electrical and acoustic effects in the process of fracturing and damage under dynamic and static combined load, and build a rock burst hazardous assessment method about the loading condition of dynamic and static load combined of coal mine.

冲击矿压是煤矿深部开采最为严重的动力灾害之一，呈现急剧增多、增强的趋势。煤在动静载组合作用下的动力学响应特征是煤矿冲击矿压研究的基础科学问题，对于揭示冲击矿压机理、指导冲击矿压监测及治理具有重要作用。本项目针对煤矿采动动静载组合作用下煤的动力学特性，首先采用微震监测技术进行煤矿井下原位测试，得到煤矿采动动载应变率、强度、波组等特征，在此基础上采用动静载疲劳试验系统、煤岩损伤过程试验系统、高速摄像系统及微观扫描系统试验研究煤的动力学特性与动载应变率、强度、波组等特征之间的相关性，以及不同动静载组合条件下煤的损伤破坏过程中微观、宏观断裂损伤特征和声电物理效应规律，以期建立煤矿采动动载条件下煤的动力学本构关系，揭示煤的能量积聚及耗散规律、煤的冲击倾向特性与采动动载作用方式的相关性、微观及宏观损伤破坏规律、煤在动静载组合作用下冲击破坏的声电物理效应规律等，构建基于动静组合的煤的冲击危险评价方法。

冲击矿压是煤矿深部开采最为严重的动力灾害之一，呈现急剧增多、增强的趋势。煤在动静载组合作用下的动力学响应特征是煤矿冲击矿压研究的基础科学问题，对于揭示冲击矿压机理、指导冲击矿压监测及治理具有重要作用。本项目针对煤矿采动动静载组合作用下煤的动力学特性，首先采用微震监测技术进行了煤矿井下原位测试，得到了煤矿采动动载的传播规律、应变率、强度、持续时间、波组等特征，煤矿采动动载应变率一般小于10-1/s，对煤矿载荷状态进行了分类，在此基础上采用动静载岩石力学试验系统、声发射系统、高速摄像系统试验研究煤的静力学及动力学特性与应变率之间的相关性，以及不同动静载组合条件下煤的损伤破坏过程中微观、宏观断裂损伤特征和声发射效应规律，建立了煤矿采动动载条件下煤的动态力学参数与应变率之间的耦合关系，揭示煤岩体冲击破坏过程中能量积聚及耗散规律、煤的冲击倾向特性与采动动载的相关性、微观及宏观损伤破坏规律、煤在动静载组合作用下冲击破坏的声电物理效应规律等，构建基于微震监测的静载CT反演与动载扰动系数的动静组合的煤的冲击危险评价方法，并提出了切顶巷弱化动载，减弱静载的冲击矿压防治方法。研究成果为基于动静载防治冲击矿压奠定了基础。