下保护层工作面过断层区覆岩裂隙-应力演化规律研究

Study on the fracture-stress evolution law of overlying strata in fault zone of lower protective layer

为深入研究下保护层开采过断层区上覆岩层裂隙发育与应力演化特征,运用相似模拟研究方法,分析下保护层开采过断层过程中裂隙场演化、顶板断层应力变化趋势、上覆岩层运移特征。结果表明:下保护层采动容易引起顶板断层附近煤岩体破碎,形成断层带;覆岩裂隙在顶板断层带内显著增加,其密度曲线呈现"W"形分布;顶板断层底端与顶端随采动工作面接近与远离应力峰值表现出不同变化;覆岩运移具有时空效应,同一层位覆岩随工作面推进位移下沉,呈现"瀑布"状分布。

For the in-depth study of protective layer mining fault area overlying rock fissure and overburden mining include stress,based on the similarity research methods,analysis of protective layer mining fault during crack evolvement,roof fault should force change trend,the migration characteristics of overlying strata.The results show that the protective layer mining is easy to cause the roof near the fault coal rock formation fault zone;rock roof increased significantly in the fault zone,the density curve is“W”shape;the bottom roof fault with the face close to show different changes and away from the table with the top cover rock stress;migration has time effect,overlying the same horizon with the advance of working face of subsidence and displacement show“waterfall”shaped distribution.