岩体结构对含煤岩系变形的控制作用

含煤岩系变形规律的研究,对煤炭资源评价和开采、煤矿瓦斯灾害预测、煤层气的可开发性评价具有指导意义。基于含煤岩系的岩体结构是控制其变形的基础因素这一前提,以岩体力学和分形几何学基本理论为指导,提出取决于岩石杨氏模量和泊松比的岩体强度因子和取决于岩层厚度的分形维数两个参数,以断层发育的安阳双全井田、褶皱发育的沁水盆地煤层气开发区及滑动构造发育的荥巩谷山井田为例,系统探讨了岩体结构对含煤岩系变形的控制作用。研究表明,低强度因子和厚层岩层较多的分形维数低值区,含煤岩系以韧性变形为主,多形成褶皱,煤体变形程度深,为瓦斯灾害严重区和煤层气难以开发区;高强度因子和厚层岩层较少的分形维数高值区,含煤岩系以脆性变形为主,多发育断层,构造煤难以区域展布,只分布在断层附近。可见含煤岩系变形不仅与岩体强度有关,而且受岩层厚度的控制。统计层段内刚性岩层的存在增加了岩体强度,岩层复杂程度的增加同样提高了岩体强度。岩体力学和分形几何学的引入,为煤岩体变形行为和程度的描述和预测提供了一种新途径。

Controlling Effects of Rock Mass Structure on Coal-bearing Rock Series Deformation

The coal-bearing rock series rock mass structure is the basic factor to control coal and rock deformation, based on this presupposition, guided under fundamental theories of rock mechanics and fractal geometry, put forward two parameters of rock mass strength factor conditional on rock Young＇s modulus and Poisson＇s ratio and fractal dimension conditional on strata thickness. To take fault developed Shuangquan minefield, Anyang, fold developed Qinshui basin CBM exploitation area and gliding tectonics developed Gushan minefield, Xinggong as examples, systematically discussed controlling effects of rock mass structure on coal-bearing rock series deformation. The research has demonstrated that： in low strength factor and thicker strata fractal dimension low area, coal-bearing rock series is mainly ductile deformation and forming mainly folds, coal mass deeply deformed, thus the areas of serious gas disaster and hard to exploit CBM; in high strength factor and thinner strata fractal dimension high area, coal-bearing rock series is mainly brittle deformation and forming mainly faults, deformed coal is hard to spread regionally and only limited along faults. Thus the deformation of coal-bearing rock series is related to not only rock strength, but also controlled by strata thickness. The rigid strata in statistical sector and increased strata complexity have enhanced the rock mass strength. The introduction of rock mechanics and fractal geometry has provided a new path to describe and predict coal and rock mass deformation behavior and extent.