The Assessment On Regional Crustal Stability Of The Jinchuan Hydropower Station On The Dadu River

The Jinchuan hydropower station of the Dadu River being planed to build is an important step station in the trunk stream of the Dadu River. It is the important energy production base in support in diversion of electricity from the western to the eastern regions. But Jinchuan region locates in the Maerkang geosyncline which is the east edge of the Bayankala miogeosyncline, Songpan-Ganzi geosynclinal foldedsystem. The geology stucture has long deformation history and tectonic superimposition deformation is complication in this region. The thrusting structure,sliding structure and decollement structure are common to see. The reasearch area is delimitated by Xianshuihe Fault and Longmenshan Fault. These two faults have strong new activity especially the Xianshuihe Fault which has cause seveal Ms≥7 earthqukes in the hidtory recorder. The Fubianhe Fault which lies in the outskirts of the dam regionalso show strong new activity. So the assessment on regional crustal stability is the main reasearch topic of the Jinchuan Hydropower Station. The estimate result possesses academic and practical significance.The paper analysis the geological background(regional stratum and rock, tectonic framework and evolution regional gravitational field, earth crust and mantle construction and deep-seated structure); the geometry,kinematics,and activity charactores of regional and outskirts faults; neotectonics character and geoklogy damage. Especialy the paper analysis the regional seism distribution rule in time and interspace and assersment the main seismic structures. Based on this The paper give the geology(determination) and fuzzy mathematics(quantitation) assersments on the regional crustal stability by the direcor of "safe island" theory.The paper give both the geology and fuzzy mathematics assersments on the Jinchuan region regional crustal stability in the first time. The main point in the geology assersment is activity faults and seism. The 7 categories 20 symboles are concerned in the fuzzy mathematics assersments. The two results of assersment fit relatively good.The earth cruster of Jinchuan Hydropower Station region is uniformity and integrity and the inter regional faults are faint in activity. The boundary faults are the locations which release the stress and their seismic intensity are VI. The outskirts Fubianhe Faults has limited infection on the dam. The geology and fuzzy mathematic assersments are all consider the regional crustal stability of the jinchuan hydropower station is "substable" which is suit for the construction of the large-scale hydraulic engineering.