STUDY ON ENGINEERING STABLITY IN TECTONICALLY ACTIVE REGION

The Wuluwati Hydropower Station on Kalakashi River in Xinjiang is located in an area with recent high active tectonic movement.The field evidence shows that fault F12 at the dam site exhibited multiphase activity up to the late Pleistocene,and faulting occurred on the North Shimen fault in the neighboring area in the Quaternary.We analysed the samples of fault materials collected along the faults at dam site and its surroundings by means of analysis of microstructures,quartz surface textures and TL dating. The results indicate that the upper time limit of the last faulting is about 30 and 20ka BP along the fault F12 and North Shimen fault,respectively,while the F30 and Shimen fault exhibited actitities by the Late Pleistocene.The structural model experiments based on distribution of the regional faults and stress field predict that stress concentration segment is located in an area far from the dam site. The dam area is a relatively stable segment.