【摘要】 某水电站厂址区岩性为晋宁-澄江期闪长岩,受地质历史多期构造运动及区域断裂影响,厂址区岩体普遍蚀变。根据风化程度、矿物组成、矿物排列方式、矿物蚀变类型、各向异性以及岩质类型等划分岩石蚀变程度为A、B、C、D四种类别,其物理力学性质由好到差依次为A类>B类>C类>D类。通过蚀变程度的研究,结合围岩工程地质综合分析,F4下盘岩体总体为A类蚀变,岩体质量好,围岩强度应力比2<S<4,围岩稳定性好,最终,将三大洞室直接布置于F4下盘岩体中。更多还原

【Abstract】 The lithology of a hydropower station site is the Jinning-Chengjiang period’s diorite,which is affected by multi-stage tectonic movement and regional fracture at the geologic history,the rock mass in the site is generally altered. According to the degree of weathering,mineral composition,mineral arrangement,mineral alteration type,mineral anisotropy and rock type,the degree of rock alteration is divided into A,B,C and D type,and the mechanical properties of the four types altered rock are studied respectively. The physical and mechanical properties from good to bad followed by A > B > C > D. Through the study of the degree of alteration,combined with the comprehensive analysis of surrounding rock engineering geology,the rock mass quality of F4 footwall fault which belonging to A type of alteration is good,and the stress ratio of its strength is 2<S<4,so the stability of surrounding rock is good. Accordingly the three underground caverns are arranged directly under the plate rock of the F4 fault.更多还原