应用三维地震勘探、钻探、断层带物质成分测试与构造历史-应力分析等方法,分析了东欢坨矿F2′断层带的几何特征、工程地质与水文地质性质。分析表明:该断层带为多条正断层组合的大规模复杂断层带;破碎带宽且富泥,泥富粘土矿物,遇水膨胀或呈流体状;断层带阻水且局部含水,承受两侧200余米水头差,水文地质性质复杂。通过灾后的突水水质分析、长观孔水位动态观测、通道调查与冲积层底部瞬变电磁探测等方法,分析了灾害因素与致灾原因。结果表明,两年前巷道工程扰动为断层活化埋下隐患,断层泥的物质成分是断层带活化的基础,开采造成的高水头差对断层活化具有促进作用。
By means of 3D seismic exploration, drilling, fault zone material composition testing and structural historystress analysis, this study analyzed the structural geometric features, engineering geological nature and hydrogeological nature of F2'fault zone of Donghuantuo coal mine. The analyses show that F2'is a large-scale complex fault zone composed by multiple normal faults with wide crushed zones rich in clay mineral mud which expands or be comes fluid under the influence of water. Water-proof but water-containing locally, this fault zone bears the water head difference of over 200 m between two hanging walls and is of complicated hydrogeological nature. Based on after-calamity bursting water quality analysis, dynamic water level observation of long term observation drill holes, channel survey and alluvium bottom transient electromagnetic detection, dlsaster-inducing factors were clarified and reasons for disasters were analyzed. Results indicate that the engineering disturbation happened 2 years ago poses a potential causes of fault activation which is based on the material composition of fault gouge while the high hydraulic head difference caused by mining promotes it.