深部煤岩动态损伤演化规律的理论及数值模拟研究

With the deepening of coal mining depth, mining dynamic phenomena occur more frequently. To prevent the occurrence of mining dynamic phenomena to lead catastrophe, the key point is to study the physical and mechanical properties and the dynamic response law of coal and rock mass under complex physical environment, such as high terrestrial stress, high temperature, high confined water pressure and intensive mining disturbance, etc. This project takes the high terrestrial stress, high temperature, high confined water pressure and intensive mining disturbance of coal and rock mass in the deep coal mine into account, combining the on-site monitoring, laboratory tests and therotical analysis, the dynamic damage evolution law will be studied for the deep underground coal and rock under complex physical and mechanical conditions.The spatial deformation and pressure distribution rule of the mining or extracting space will be monitored on-site using the pressure sensor, acoustic emission and electromagnetic radiation detectors. And in the laboratory, under different temperature conditions, the uniaxial compression tests, triaxial compression tests and those compression tests with different seepage media of coal samples will be conduct to do creep experiments, through the experiments, to study the creep law and damage evolution law of coal samples under different physical and mechanical conditions. Applied the thermodynamics and damage mechanics theory, based on the results of laboratory tests and field monitoring, the generalized potential damage dissipative energy evolution law of coal and rock will be theoretically analyzed under different physical and mechanical conditions, and then, the multi-field coupling dynamic damage evolution constitutive relation of coal and rock will be established, and the therotical model will be verified by the experimental results. Considering the time and space evolution law of deep coal and rock mass damage, the numerical simulation program will be developed to numerical study the dynamic damage transmutation of deep coal and rock mass in the intensive mining disturbance conditions with multi-field coupling. The results of this project can provide a theoretical support to prevent the dynamic disaster happening in the deep mine for the specific mining conditions.

随着煤矿开采深度不断增加，矿山动力现象越发频繁。要预防矿山动力现象致灾的发生，研究煤岩体在复杂物理环境下的物理力学性质及动力响应规律是关键。本项目充分考虑深部煤岩体所处的"三高一扰动"特殊物理力学环境，采用现场监测、实验室试验和理论分析相结合的方法研究多物理场耦合作用下煤岩的动态损伤演化规律。现场监测特定采掘条件下深部矿井采掘空间变形及压力分布规律；实验室开展不同温度条件下的单轴及三轴压缩蠕变试验、以及不同渗流介质参与下的三轴压缩渗流蠕变试验，研究煤岩试样在复杂物理力学环境中的蠕变变形规律及损伤演化规律；利用热力学及损伤力学基本理论，分析实验室试验和现场监测结果，理论分析煤岩体内部损伤耗散广义势演化规律，建立煤岩多物理场耦合动态损伤演化本构关系并进行验证；编制多物理场耦合动态损伤数值模拟软件，研究深部矿井特定采掘空间煤岩体动态损伤演变规律及灾变可能区域，为深部矿山动力灾害预防提供理论支持。

我国浅部煤炭资源储量逐渐枯竭，煤炭资源开采逐步转向深部矿井开采。深部煤炭资源开采过程中，煤矿工况点将面临，其浅部表现出的应力分布及动力响应规律及防治技术是否适用于深部煤炭资源开采，需要开展大量的研究工作。深部开采煤岩体受“三高一扰动”的影响，其采动过程中的动力发生频次及强度必将大大增加。有效预防或者控制煤岩体动力响应的关键在于弄清楚煤岩体在复杂物理力学条件下的材料的力学性质和动力响应规律，并弄清楚其主控因素之间的耦合作用规律，项目开展深部煤岩在复杂物理力学环境中的动力响应机制研究具有重要的理论意义和实用价值。.项目通过分析现有的深部煤炭资源开采过程中常出现的动力现象，考虑其关键影响因素，主要开展了以下几个方面的研究工作：1.实验室开展煤岩多物理场耦合试验研究，研究获得含瓦斯煤岩蠕变、煤岩蠕变渗流、循环加卸载、加载瓦斯吸附解吸、温度-渗流-蠕变等损伤演化规律；2.利用热力学基本定律及损伤力学基本理论，建立了含瓦斯煤岩蠕变、蠕变损伤、渗流蠕变损伤及温度-渗流-蠕变损伤理论模型，结合试验结果验证了模型的正确性；3.基于理论研究基础，通过二次开发，编制用户子程序结合数值模拟程序，实现深部煤岩多场耦合围岩应力分布规律及损伤演化规律数值模拟研究，模拟得到了特定开采条件下工作面围岩应力分布规律及损伤演化规律。.项目通过实验室试验、理论分析和数值模拟相结合的研究方法，系统研究了深部煤岩受温度、压力、流体渗流、吸附解吸等因素耦合作用下的力学响应规律并建立了相应理论模型，通过试验和数值计算初步验证了模型的合理性，项目研究方法及成果可为我国深部煤炭资源开采过程中的动力灾害预测预报提供理论支持。依托项目设计研制的试验系统可进一步提供大量的实验室试验研究，为复杂物理力学环境中的深部煤岩体动力响应及演化规律提供试验数据支持。项目研究成果对开展深部煤岩体动力响应规律及灾害防治具有重要的理论意义和实用价值。