【摘要】 通过现场调查结合勘测资料分析了天池抽水蓄能电站上坝址蚀变岩体的分布规律;利用薄片鉴定、电镜扫描及X射线粉晶衍射分析试验对蚀变岩体进行了岩石成分和化学成分分析,研究了蚀变作用的地质成因、蚀变机理,结合室内试验获得了蚀变岩的物理力学指标;利用FLAC3D软件对不同工况、不同高程河床蚀变岩趾板建基面进行了数值分析计算。研究结果表明:在左岸和右岸由于强风化下限埋深不大,建议挖除,趾板建基面选择在中等风化的中条期混合花岗岩上;控制坝基变形的主要地质因素是存在于坝基范围内的断层破碎带F₂₅断层以及断层周围由于蚀变造成的砂状岩芯,对大坝沉降影响不利;河床蚀变岩趾板建基面优化数值模拟研究表明,河床部位以在930⁹50 m之间作为趾板建基面是适宜的。更多还原

【Abstract】 By combination of survey data and field investigation of the Tianchi pumped storage power station dam,the distribution of altered rock was researched.By use of thin section identification,scanning electron microscope and X-ray diffraction analysis test,the altered rock of rock composition and chemical composition was analyzed.The geological causes of alteration and alteration mechanism was studied and the physical and mechanical parameters of altered rocks were obtained with laboratory experiments;altered rock riverbed toe slab foundation is numerically calculated and analyzed by using FLAC3 D software in the different conditions and the different elevations.The results show that:on the left bank and right bank of the maximum depth of weathering is not as strong and the proposed excavation and toe slab foundation was in the bar in the middle of the mixed granite;the alteration of sand-like core presented in the range of dam foundation F₂₅ fault and around the fault zone is the main geologic factors of dam deformation and the adverse impact of the dam settlement;the numerical simulation of river altered rock toe slab foundation optimization showed that the riverbed of the 930 950 m elevation being as base surface is appropriate.更多还原