In-situ stress measurements were carried out with the help of the small borehole hydraulic fracturing test unit in 10 test sites respectively belonging to 3 coal mines in Yitai coal mining area. The test results show that the coal mining area belongs to the low stress zone, the tectonic stress dominates absolutely, and the primary horizontal stress mainly aligns with north-east;stress values differ from each other among coal mines in the coal mining area, and the direction of the principal horizontal stresses also vary from one mine to another mine. Based on the measurement data, the difference between the maximum principal horizontal stress and the minimum horizontal stress, or the maximum principal horizontal stress and the vertical stress, are relatively large, and this stress configuration leads to high shear stress in the rock mass. The law of stress distribution with overburden depth was analyzed, and the relation between the principal horizontal stresses and overburden depth was established.%采用小孔径水压致裂地应力测量装置在伊泰矿区3个煤矿完成了10个测点的原岩应力测量.实测数据表明:矿区应力场属于低地应力值区域,构造应力占绝对优势,最大水平主应力方向以北东方向为主;由于受埋藏深度、地质构造和地形地貌影响,各矿地应力值差别较大,最大水平主应力方向亦有所偏差.基于实测数据,得出最大与最小水平主应力,最大水平主应力和垂直应力的差值普遍较大,导致岩体内剪应力较大;分析了地应力随埋藏深度的变化规律,并得出水平主应力与埋深之间的关系.
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