上覆巨厚砾岩与断层耦合作用下冲击地压机理研究

Coupling effect of huge thick conglomerate and fault bring a great threat to coal mining safety. The mechanism of rockburst under the effect of huge thick conglomerate layer and fault interaction will be studied by field monitoring, theoretical analysis, numerical simulation and experimental research, field application and comprehensive analysis. First of all,we will develop a special white light digital speckle correlation method using in non-uniform material and discontinuous deformation field measurement, and create a view, high resolution experimental observation system which consists of this method and high speed camera system. The fault model experiment will be systematically researched by the new digital speckle correlation method. We will study the fault deformation and sliding starts, sliding propagation, and obtain the fault slip characterization parameters, establish the fault sliding criterion and constitutive relation of fault contact surface(zone) by the model experiment; Secondly,we will establish the coupling mathematical model of deformation-fracture of huge thick conglomerate and deformation - slide of fault, develop the finite element calculation program by introducing the nonlinear contact elements and life and death unit technology. Finally, the process of rockburst which is induced by fault, huge thick conglomerate , coupling effect of huge thick conglomerate and fault are numerically simulated by the finite element program. We will systematically analysis the mechanism of rockburst according to the properties of huge thick conglomerate movement evolution, the evolution of fault slip, coupling effect of huge thick conglomerate and fault , energy evolution of surrounding rock, stress and displacement evolution of surrounding rock, and put forward the control measures of rockburst

上覆巨厚砾岩与断层两种不利地质条件耦合作用，给冲击地压防治带来巨大困难。项目采用现场监测、理论分析、数值模拟、实验研究和综合分析方法，从上覆巨厚砾岩结构演化、断层滑动演化及相互作用入手，开展上覆巨厚砾岩与断层耦合作用冲击地压机理研究。首先，发展非均匀、不连续变形场实验测量方法；实测断层变形场及断层滑动演化规律；研究断层滑动状态表征参数，在此基础上建立断层滑动判据及断层接触面(带)本构关系；其次，建立上覆巨厚砾岩变形-破断与断层变形-滑动及其耦合数学模型；引入非线性接触面单元和生死单元技术，在商业软件的基础上开发有限元计算程序；开展采动条件下上覆巨厚砾岩与断层耦合作用数值模拟研究；最后，总结上覆巨厚砾岩结构演化、断层滑动演化及工作面、巷道和围岩应力分布、能量演化规律；根据煤岩体冲击倾向性、强度和能量演化等综合指标，分析上覆巨厚砾岩与断层耦合作用的冲击地压发生机理，提出冲击地压治理方案并优化。

上覆巨厚砾岩是煤矿采掘工程中一类特殊地质条件，我国多个矿区都有分布，断层是煤矿采掘工程常见的地质构造形态，上覆巨厚砾岩与断层是目前我国采矿工程中所面临具有孕育冲击地压灾害的两种开采地质条件。上覆巨厚砾岩与断层两种不利地质条件耦合作用，给矿井安全生产带来巨大的隐患。因此，开展上覆巨厚砾岩与断层耦合作用下冲击地压机理研究，具有重要的理论和实践意义。.研究工作主要体现在以下几个方面：.（1）发展了一种非均匀、不连续变形场测量的数字散斑相关方法。基于移动最小二乘法的节点位移来构造整个待求位移场的近似函数，选取节点权函数及确定权函数的影响域大小，根据优化目标和位移场表征，建立优化模型，采用Newton-Raphson方法对优化模型进行求解。给出非均匀、不连续变形场中形函数的确定方法。通过理论散斑图像和实验散斑图像进行分析，对权函数、影响域及布点方案进行调整；.（2）揭示断层摩擦滑动位移时空演化规律，得到断层滑动状态表征参数。开展不同条件下的断层滑动实验研究，并利用非均匀、不连续变形场测量方法及搭建的数据采集系统，实测断层位移场、变形场及断层滑动成核演化规律，基于非均匀性统计指标、应变能密度、声发射振铃计数、声发射累计能量、声发射b值及应力比值等物理和力学指标对断层滑动状态进行特征提取。.（3）建立岩层变形-破断和断层变形-滑动数学模型。以岩石巴西劈裂、三点弯曲实验为基础，分析岩层本构关系及破断判据；通过断层摩擦滑动实验和力学模型，分析断层滑动判据及滑动本构关系。以砾岩本构关系和破断判据、断层本构关系、断层滑动判据为基础，建立上覆巨厚砾岩变形-破断数学模型、断层变形-滑动数学模型，通过有限元程序开发，模拟采动条件下上覆巨厚砾岩与断层耦合作用的砾岩岩层应力和位移演化、断层滑动演化特征及相互关系。.（4）开展冲击地压机理及防治措施研究。以义马矿区为研究对象，根据现场资料总结上覆巨厚砾岩岩层结构演化、断层变形滑动演化及工作面、巷道和围岩应力分布、能量演化规律；采用相似模型试验和数值模拟方法，研究上覆巨厚砾岩与断层耦合作用的冲击地压发生机理。开展锚固体系变形场演化规律实验研究。