受载岩体变形、滑动过程中反馈特性研究

The nature occuring many dynamic disaster in mining engineering is the positive feedback effect occurrence of the coal and rock on the interaction of various internal and external factors. The project uses the high speed and high power camera and measures the number of the cracks on the surface of the rock sample with the nonlinear growth of the process of the load deformation. It determines the change law of effective bearing area of the rock sample on the process of the uniaxial compression, the uniaxial compression creep, the tensile creep of the diametral compression. Using the experiment of the bottom friction, it determines the change law of the surface roughness and the damping coefficient of the sliding sample. Using the theoretical method, it determines the feedback circle and the feedback relation of the ratio of load and the effective loaded area with change of deformation, builds occurrence conditions and criteria of the positive feedback of the load system between uniaxial compression deformation, the compression creep, the tensile creep of the diametral compression, shear creep deformation, the creep deformation of the soft rock and time and the sliding sample. It studies two, three or many complex rock structures and the sliding process of the complex sliding surface of the pressure and shear unified, forming cambered surface after the rock cutted, the wearing layer surface and corresponding the positive and negative feedback characteristic. The project can provide the theoretical basis for the occurrence mechanism, prediction and forecasting of the dynamical disaster of the mine.

采矿工程中众多动力灾害发生的实质是煤（岩）体在各种内外因素相互作用下发生正反馈效应。项目采用高速、高倍照相机，测定岩石试件表面的裂纹数量随加载变形过程的非线性增长关系，分别确定岩体试件单轴压缩、单轴压缩蠕变、对径压缩拉伸蠕变等过程中有效承载面积的变化规律；利用底摩擦实验测定滑动试件滑面的粗糙度、阻尼系数变化规律。利用系统动力学方法确立载荷与有效承载面积之比随变形变化的反馈环与反馈关系，分别建立单轴压缩与变形、压缩蠕变、对径压缩拉伸蠕变、剪切蠕变变形、软岩蠕变等变形与时间之间的加载系统正反馈发生条件与判据；确立滑动阻力、位移、滑动速度与时间之间的反馈环与反馈关系，建立滑动试件正反馈发生条件与判据。分别研究两个、三个及多个复杂岩体结构及压剪统一、岩体剪断后形成弧面、穿层滑面等复杂滑面滑动过程及对应的正、负反馈特性，为揭示矿山动力灾害发生机理，预测、预报、治理灾害发生提供理论基础。

项目在受载岩体系统动态反馈层次特征方面，将地下采场系统划分为受载煤（岩）体系统、蓄能体-变形体系统与巷道-巷道系统，系统受到外界扰动时三个子系统逐层触发，三者的反馈类型共同决定了采场系统的动力灾害类型及规模；分析了岩石（煤）在压缩变形过程中不同阶段的反馈特性，结合MATLAB 与有限差分软件FLAC3D生成非均质岩石模型，分析了非均质程度对岩石试样力学性质的影响，建立反馈环并分析其反馈特性；给出了滑体在外界扰动下发生滑动的机理，将滑体滑坡的全过程划分为滑体从起动到稳定缓慢滑动阶段、滑体非稳定的加速滑动阶段、减速终止阶段，采用系统动力学理论建立方程，分析其滑动的过程；分析岩石试件-试验机系统的反馈特性和加载速率对岩石变形破坏的影响；自主设计并研制了多功能岩石孔隙-裂隙渗流试验系统装置进行砂岩单裂隙渗流试验，分析裂隙表面粗糙度与裂隙渗流的欧拉数的正相关关系；自制实验设备进行岩石拉张蠕变实验，分级加载下岩石的拉张蠕变也包括三个阶段：初始蠕变阶段、等速蠕变阶段和加速蠕变阶段。项目从系统的角度研究岩石的变形、破坏等，丰富了岩石力学研究的思路，对研究岩石力学系统的演化和重新认识岩体工程的稳定性有重要意义，同时也可为全国各类煤矿生产、边坡稳定的治理、预测、预报及预警提供基础理论，具有广泛的应用前景。