ANALYSIS OF CRUSTAL STRUCTURE UNDER PENGSHUI HYDROPOWER STATION BY RECEIVER FUNCTION

With installed capacity of 1.75 million kilowatts and total investment of 23 billion yuan,the Pengshui hydropower station on Wujiang-river is the biggest hydropower station of Chongqing.The dam of the station is about 116.5 meters high,the normal water level is up to 293 meters,and the reservoir capacity is 1.335 billion cubic meters.Researches show that the crust around the dam is stable,but the impoundment of the reservoir may induce moderate and strong earthquake in the potential seismic sources zone.On basis of teleseismic waveform data from 2008 to 2010 recorded by Pengshui Hydropower seismic network,this paper studies the crustal thickness and Passion's ratio of the area using receiver function method.The results show that the crustal thickness range from 43.9 to 47 km and the Poisson's ratio ranges from 0.20 to 0.24.