关键词: 云南, 阳宗海电厂, 场地地震地质条件

Abstract: The Yangzonghai thermal power plant is located in Xiaojiang strong seismic zone, Yunnan province. Fundamental earthquake intensity of the area is Ⅸ degrees. This puts a great constraint on the further extension of the plant, which is necessary to make full use of the favourable power supply to Yunnan province.The Xiaojiang fault zone consists of two branches (the east and west branches) and the site of the plant is located in between both of them being strong seismic activity zone in history. An earthquake of magnitude 8 occurred in 1833 near Song-Ming county on the west branch.A geological cross-section was dug in Dongguyayin village, it is found that the recurrence for magnitude 7 is at least 300 years and magnitude 8 is at least 1000 years. So there is little possibility for an earthquake over magnitude 7 to occur in coming 100 years.Geomorphologically plant area is shown as terrace, with a low relief. The bedrock consists of dolomite. The rock formation gently dips away from the lake Yangzonghai and underlies the red clay. The underground water level is deep. All of these suggest that the foundation of the plant is steady, more beneficial for antiseismic building.As stated above, it is clear that the fundmental earthquake intensity of the Yangzonghai power plant can be lowered from Ⅸ down to Ⅷ degrees.

Key words: Yunnan Province, Yangzonghai, Earthquake, Seismogeological conditions