摘要
大型水利水电工程水库诱发地震历来受业主、工程技术人员的重视。三峡工程蓄水10多年来,在蓄水过程中,三峡库区较蓄水前地震明显增多。本文选择了三峡库区既有活动断裂,又有可溶岩和煤层分布的近坝库段作为研究对象,通过对库区地震活动与水位的关系和诱发地震空间展布特征分析,认为:三峡水库诱发地震,发生在有可溶岩和含煤地层部位的塌陷型地震占总数的90%,而非可溶岩和不含煤地层中只占总数的10%;近坝库段地震主要发生在仙女山断层北端,且有地震呈丛集活动的特征;九湾溪断层上盘远离长江部位地震零星分布,距长江较近地段地震相对增多,下盘地震极少。地震与水位的对应关系十分密切,三峡水位上升,长江两岸发生的小地震较多,当水位蓄至175m时,地震主要发生在仙女山断裂的北端和九湾溪断裂的上盘及北端。
Reservoir induced earthquakes of large-scale hydropower technical personnel. The Three Gorges reservoir has been impounded the reservoir increases significantly during the impoundment. An area project have always a concern of owners and for 10 years, and the earthquake frequency in near the dam site and with active faults, car- bonatite and coal seams is chosen as the research object. Analyze the spatial distribution of reservoir induced earth- quakes and the relationship between earthquake and reservoir water level. The analysis results indicate that 90% of the reservoir induced earthquakes are collapsing induced by earthquakes which occurred in carbonatite and coal seams. The other lO%occurred in other stratums. It also indicates that the attitude of stratum has a significant effect on reservoir induced earthquakes. The earthquakes near the dam site have clustering distribution characteristic, which mainly occurred at the northern part of Xiannvshan Fault. Some earthquakes occurred in the hanging wall of Jiuwanxi fault, which occurred more at the nearby site of Yangtze river and less in the faraway site, while rarely oc- curred in the heading wall of the fault. The reservoir induced earthquakes and reservoir water level are closely relat- ed. While the water level of Three Gorges reservoir rises, many small earthquakes occur on both sides of Yangtzeriver. When the water level rises to 175m, most of the earthquakes occur in the northern part of Xiannvshan fault and the hanging wall of Jiuwanxi fault.
出处
《工程地质学报》
CSCD
北大核心
2013年第6期932-937,共6页
Journal of Engineering Geology
关键词
三峡水库
近坝库段
诱发地震
特征分析
Three Gorges reservoir, Reservoir near the dam site, Reservoir induced earthquake, Characteristic a- nalysis
