巨厚砾岩条件下断层应力采动效应及对煤岩动力灾害的作用机制

The engineering background of the current application is the mechanism of fault reactivation and the coal bumps it leaded. The non-linear behavior of coal bumps and mechanism of fault reactivation can not be obtained by the current test method of theories, that is the key scientific issues of this current application. This project focuses on the fault stress evolution law of surrounding rock by the mining effect and action mechanism of coal and rock dynamic disasters. Two similar model experiments were taken to simulate the stoping face with a fault. The evolutions of the fault stress and abutment stress response to the transient process of fault slip were both studied, meanwhile, summarized mechanism of the fault reactivation caused by mine-induced stress. Based on the double shear friction method, sliding friction experiment was designed for rock and coal samples to simulate the fault reactivation and destabilization of coal and rock structure combination. In the experiment, the thesis studied the prerequisites of instability sliding, the sliding type under certain conditions, displacement evolution and acoustic emission characteristics with the sliding process. Mathematical model was built to describe the fault sliding. Based on the coal deformation and failure characteristics, the model can fit the attenuation creep and accelerated creep pattern. Fourth, numerical means was used to study the law of fault reactivation influenced by the exploitation way, giving a supplement and verification of the conclusions of the indoor experiment.

以巨厚砾岩条件下断层构造区域冲击地压发生机理为背景，针对现有实验方法和理论不能揭示采动诱发断层活化机制及煤岩非线性力学行为的现状，围绕开采扰动条件下地质构造区域煤岩冲击失稳机理这一关键科学问题，研究断层围岩应力演化规律的采动效应及对煤岩动力灾害的作用机制。通过2组含断层的工作面开采相似模型实验，研究开采过程中断层应力状态的演化规律，分析开采活动导致断层活化的机理以及断层滑移瞬态过程煤体支承压力的动态响应；利用双面剪切试验法对多种岩性的煤岩组合试样进行滑动摩擦实验，模拟断层的活化错动和煤岩结构的滑动突出，研究煤岩组合样本产生失稳滑动的条件、特定条件下的滑动类型以及滑动过程的位移演化和声发射特征；据此建立以流变模型组合元件为基础的描述断层失稳滑动规律的力学模型，并将其转化为数值计算本构关系，研究不同开采方式下断层活化特征；最终揭示开采扰动、断层活化及煤岩冲击失稳之间的作用机理。

冲击地压是发生在矿山开采中的一类煤岩动力现象，往往会带来巨大的损失和次生灾害。冲击地压因其发生原因复杂，影响因素多，发生突然，破坏性大而成为矿山岩石力学、矿山压力研究中的重大课题之一。.根据冲击地压发生的统计规律，在地质构造发育的区域往往更容易发生冲击地压灾害，断层便是其中一种重要的诱发冲击地压的构造。由断层活化诱发的冲击地压往往具有破坏性强、冲击范围大、发生突然而猛烈的特点，造成巨大的破坏和严重的后果。对于断层方面的研究，地震学家们对各种形式的断层模型做了相关研究，并取得了一系列成果，但这些仅限于断层结构在地震学上的意义，并不涉及开采扰动或采场覆岩运动等对断层结构的影响以及开采扰动、断层活化、工作面冲击这三者之间的作用联系。.通过实验室实验、数值计算、理论分析和现场实践相结合的研究方法，对断层诱发冲击地压的发生机理和防治手段进行了研究，通过断层影响下工作面过回采的相似实验模型，研究开采过程中断层应力状态和滑动位移的演化规律，分析开采活动导致断层活化的机理以及断层滑移瞬态过程煤体支承压力的动态响应；利用双面剪切法对多种岩性的煤岩组合试样进行滑动摩擦实验，模拟断层的活化错动和煤岩结构的滑动突出，研究煤岩组合样本失稳滑动的产生条件、特定条件下的滑动类型以及滑动过程位移演化和声发射特征；根据实验获得的煤岩组合结构变形和破坏特征，建立以流变模型为基础的断层失稳滑动数学模型，实现了断层失稳滑动过程的拟合；运用数值计算的手段，研究开采方式对断层活化规律的影响，补充并验证了相似模型实验的结论；以现场的冲击地压案例分析断层影响下的冲击地压发生规律，评价多参量监测预警方法和解危措施。