ENGINEERING EFFECTS TO DALIUSHU DAM SITE DUE ACTIVE DISLOCATION OF ADJACENT FAULTS DURING MAJOR EARTHQUAKES IN QINGHAI-TIBET PLATEAU

The Daliushu Dam Site in the Heishanxia Gorge of the Yellow River is seated in the middle of Zhongwei-Tongxin active fault zone. It is apart 1.5 km from the seismogenic fault F201. The results of statistics indicated that the rupturing effects such as branch fractures and secondary fractures will be appeared around the adjacent 3~5 km area from seismogenic fault, if the Ms7.0 Earthquakes happen in the Qinghai-Xizang plateau and its margins. The Daliushu Dam Site is located in the zone of branch fracture occurrence when Ms7.0 Earthquakes happen., So, engineering rupturing effects will be in existence. Result of 3-D finite element analysis indicates that the dislocation ratio of the faults F93, F39, and F40 relative to the fault F201 arrives at 14.38%、12.0% and 9.84% respectively, when the rupturing effects of fault F201 happen.