沟谷区域浅埋厚煤层开采应力场分布及矿压显现特征

Stress field distribution and strata behavior characteristics in shallow thick coal seam mining in gully region

针对沟谷区域浅埋厚煤层开采工作面易发生动载矿压灾害的情况,采用数值模拟、理论分析与现场实测相结合,分析了沟谷地形下煤岩层原岩应力场分布特征与煤层开采期间覆岩应力场、位移场及工作面矿压显现规律。研究表明:沟谷地形对煤岩层原岩应力场的影响程度随煤岩层埋深的增大而减小,根据其对下覆煤岩层原岩应力场的影响程度的变化,可将沟谷地形下不同深度范围煤岩层分为显著影响区、影响减弱区和无影响区;工作面推进方向与沟谷沟底走向之间可分为平行、垂直和斜交3种情况,不同情况下工作面开采围岩应力场、位移场分布特征的不同,是引起工作面矿压显现差异化的根本原因。通过对沟谷地形下工作面矿压显现特征及支架承载特性的实测分析,对易出现动载矿压的情况进行了分类。

For the situation of various factors affecting strata pressure in shallow thick coal seam mining in gully region,numerical simulations, theoretical analyses and field measurements are adopted to study the distribution characteristics of in-situ rock stress field, the distribution law of the stress, displacement field of overlying strata and the ground pressure behave law in coal seam mining in a valley terrain.The researches show that the influence of valley terrain on the in-situ rock stress field of coal and rock decreases with increasing of the buried depth. The coal and rock strata of different depth in the gully terrain can be divided into the significantly affected area, the influence weakened area and the uninfluenced area according to changes. The relationship between the gully toward and the advancing direction of a mining face can be divided into the parallel, perpendicular and oblique crossing. The primary cause of the difference of mining face pressure is the stress and displacement field distribution of surrounding rock under three different situations. The prone areas of dynamic strata pressure accidents are classified through the analysis of strata behavior characteristics and supports bearing properties of mining face in the gully terrain.