动力扰动对卸压煤体内部微结构影响与增透机理研究

Both internal structure and permeability are obviously improved in pressure-relieved coal. If pressure-relieved coal is affected by dynamic disturbance again, more fundamental changes may be produced, which not only be good at improving the extraction efficiency of coal seam gas, but also causing serious gas accidents if the gas enrichment area and the mining space is connected because of the improper control of pressure-relieved degree. Therefore, research on both the effect on internal structure and mechanism of improve permeability caused by dynamic disturbance is a necessary project. All the way of theoretical analysis, experimental test, numerical simulation and situ observation are adopt by this project, Dynamic disturbance is simulated by dynamic impact generated by the Hopkinson test system, and with the self-made coal rock meso mechanical properties measurement and control system, the influences on the internal structure of pressure-relieved coal caused by dynamic disturbance are systemic studied in order to obtain the evolution law of internal structure and gas desorption and gas flow caused by the size, frequency, and relationship with the unloading direction of dynamic disturbance, and establishing the coupling relationship between pore number, scale evolution and the above three factors , and establishing the mechanical model described the development of internal micro structure under dynamic disturbance, and putting forward to the mechanism of improve permeability of pressure-relieved coal when the dynamic disturbance is considered as the key control factors.

卸压煤体的内部结构的发育程度、渗透特性均会被明显提高；如再受到动力扰动作用，变化可能更加剧烈，这虽然对提高煤层瓦斯抽采的效率有利，但若控制不当则可能导致瓦斯集聚区与采掘空间的导通，造成严重瓦斯事故。因此，研究动力扰动对卸压煤体内部微结构影响与增透机理非常必要。本项目拟采用理论分析、试验研究、数值模拟和现场实测综合的方法，以霍普金森试验系统产生的动力冲击模拟卸压煤体受到的动力扰动作用，配合自制的煤岩细观力学特性测控系统，针对动力扰动对卸压煤内部结构产生的影响开展系统的研究，以期获得动力扰动大小、频率、与卸压方向的关系三个因素对卸压煤体内部结构产生的影响规律、对瓦斯解吸、流动的影响规律，建立三个因素与卸压煤内孔隙数量、尺度演化的耦合关系，建立描述动力扰动影响下卸压煤体内微结构发展的力学模型，提出考虑动力扰动为主控因素的卸压煤体增透机理，为提高卸压瓦斯抽采效率、预防矿井动力灾害提供理论指导。

本项目开展了系统的实验室试验研究、数值模拟、现场实测研究工作。研制开了适用于本项目研究的辅助试验设备和现场使用的技术设备；从理论上掌握了动力冲击对煤岩体内部微结构产生的影响规律、不均匀载荷对瓦斯抽采钻孔围岩起裂、裂纹演化等规律，不均匀性对煤层内瓦斯运移、放散产生的影响规律，提出了基于轮替思想和疏水增加煤层渗透特性的技术方法和不均匀煤层等效渗透率基本理论；研发的煤层增透与瓦斯抽采钻孔维护技术经山煤集团鹿台山矿应用后效果良好。项目组成员先后有17人次参加国际、国内学术交流，并作大会报告3次；培养硕士研究生10名，其中已毕业7名(三人获校优秀论文)、博士研究生3名；项目主持人职称晋升教授职称；第一标注在国际国内重要学术期刊共发表学术论文21篇，其中SCI收录3篇、期刊EI收录6篇(尚有3篇处于待发表状态)；获授权专利11项，软件著作权1项；出版专著一部；获行业省部级科技进步三等奖1项。