【作者】 李海涛；

【导师】 姜耀东；

【作者基本信息】 中国矿业大学（北京） ， 采矿工程， 2014， 博士

【摘要】 介质属性将会受到加载环境的显著影响，其中以加载速率影响最为突出，本文即以不同加载速率影响下煤的力学行为展开研究。分析率效应在现场尺度下的具体影响，设计多加载速率力学试验，发现当加载速率高于某临界值时，煤的强度将随加载速率升高而降低，与岩石不同，针对该现象展开机理研究，考察了裂隙发育及承载结构破断对于率效应的影响，指出率效应影响下煤的特有力学行为是在二者共同作用下发生，以此构建能够反映特有力学行为的本构模型，并将该现象与冲击特性相关联，借鉴现有冲击特性评价指标计算方法发现，煤的冲击特性同样表现出率效应和临界值，并指出临界加载速率条件下的煤具有最危险状态，为此，构建工作面推进速度和加载速率转换关系，设计了考虑率效应的冲击特性评价方法，以实现现场尺度下对于临界加载速率的预警，并提出人为增加煤体破裂面的方式应对临界加载速率带来的危险，现场应用表明，该评价方法具有较好的指导意义。更多还原

【Abstract】 The attribute of the medium would be notable iMPacted by the loadingenvironment, and the loading speed was the most important parameter. This paperfocused on the mechanical properties of coal under different loading speed. Based onthe analyzing of the field observation of the rate effect, various loading speed tests weretaken. It was found that when the loading speed was over some critical value, thestrength of coal would decrease with the increasing of the loading speed, and this wasnot the same with rock. The mechanism of this phenomenon was researched with theeffect of the development of the fracture and the breaking of the bearing structure onthe rate effect considered. It was pointed out that the mechanical properties of coal withrate effect was effected by both of the development of the fracture and the breaking ofthe bearing structure, and a constitutive relation which could reflect this kind of specialmechanical properties was created. This phenomenon was related with burst propertyof coal and rock, Given the current calculation method for the burst property index, itwas proved that the burst property of coal also had a rate effect and critical value, andit was pointed that coal under critical loading speed was in the most dangerous state. Inorder to use this conclusion, the conversion relation between the advanced speed of theworking face and loading speed was built. The method for evaluating the burst propertywith rate effect considered was put forward, and this method was useful for the safetyof coal mine by offering a early warning value. Artificial failure face increased byworkers could enhance the adaptability of working face to the advanced speed was also point out. The field observation showed that the mentioned method was positive forcoal mine safety production.更多还原