乌东德水电站左岸拱座长大结构面工程地质特征及其影响研究  

GEOLOGICAL CHARACTERISTICS OF DISCONTINUITIES AT LEFT BUTMENT SLOPE AND IMPACT EVALUATION TO DAM OF WUDONGDE HYDROPOWER STATION

作　　者：王吉亮[1,2] 许琦[1,2] 郝文忠[1,2] 黄孝泉[1,2] 魏雨军 周炳强[1,2] 徐磊[1,2] 

机构地区：[1]长江三峡勘测研究院有限公司,武汉430074 [2]长江勘测规划设计研究有限责任公司,武汉430010

出　　处：《工程地质学报》2016年第5期823-832,共10页Journal of Engineering Geology

摘　　要：拱坝所承受的荷载大部分都通过拱的作用传到两岸拱座岩体,拱坝所具有的一切优点都是建立在拱座稳定的基础上的,因此拱座是确定拱坝稳定的关键部位,拱座变形及抗滑稳定问题是拱坝建设中的关键工程地质问题之一。乌东德水电站左岸拱座在开挖过程中揭露两条长大结构面。本文从工程地质条件着手,在可研阶段的研究基础上,布置专项勘探,并充分利用施工揭露,查明了结构面的空间分布特征;利用大比例尺编录及物探测试,实现了结构面充填物性状的定量化研究;在此基础上,结合工程地质评价及数值计算分析结构面对拱座稳定性的影响。研究结果表明,这两条结构面为典型灰岩地区后期溶蚀作用改造前期构造痕迹形成的溶蚀性小断层,充填物以钙质胶结为主,胶结紧密,局部溶蚀性状较差,充填物中软弱物质断续分布,多为坚硬岩体直接接触;受其空间分布特征影响,结构面会引起拱座岩体局部应力集中,但对拱座抗滑稳定性无影响。所获得的成果基本形成了拱座岩体长大结构面工程地质特征及其影响研究的系统方法,可应用于现场实际工程,对拱坝的勘测、设计等具有重要的理论和实践意义。The load on the arch dam mostly applies on the abutment rock mass of both sides of dam. Dam abutment is key part to maintain stability of arch dam and its stability is one of the important engineering geology factors in the process of arch dam construction. Two geological discontinuities with long persistence are found during the excavation of slope at left abutment of Wudongde hydropower station. According to the engineering geological conditions and data of feasibility study, in combination with special exploration and exposure of excavation surface, the distribution of discontinuities is obtained. The quantitative research about the physical composition and character of infillings of discontinuities is achieved through field investigation in detail and geophysical exploration test. Based on the results, the adverse impact of discontinuities to the stability of abutment is researched through engineering geological evaluation and numerical analysis. The results show that these discontinuities are two tectonic faults formed in the earlier stage and superimpose the modification of dissolution later. It is a typical phenomenon in limestone zone. Most of the infillings exist with calcium cementation. Partial infillings are poorer because of dissolution. Thus, the distribution of soft material of infillings is discontinuous. Hard rocks contact each other directly. The discontinuities have no impact on the abutment stability, but may cause the stress concentration in abutment rock mass partly. The developed approach is scientific and comprehensive. It can be applied to study the engineering geological characteristics of discontinuities and evaluate their impact to the stability of abutment rock mass in the process of dam construction. It also provides theoretical and practical significance to the survey and design of arch dam project.

关 键 词：乌东德水电站 拱座 长大结构面 空间分布 工程地质特性 影响性评价 

分 类 号：P642[天文地球—工程地质学]