Abstract: We have analyzed the deformation texture,new activity,mechanical and fractal features of the Enshi fault in western Hubei Province. Adding with fault activity dating,we make a complete study to the activity of this fault. It is suggested that deformation of the Enshi fault has evident characters of segmentation. It has been active for many times and was active during the new tectonic period. Its activity is,however,very weak at present time. It is determinted that the last time of activity is more than 0.2Ma ago. Therefore this fault is not an active fault for engineering and will not bring major damage to the neighbouring hydropower projects.

Key words: Fracture zone, Engineering geology, Hubei

摘要： 通过分析恩施断裂的变形结构、运动学和动力学特征以及新活动和几何分形结构特征,结合断裂的活动时间测定,对湖北西部恩施断裂的活动特征进行了全面的研究,认为恩施断裂变形分段特征明显,活动具有多期次,且新构造期曾有活动,但现今活动极其微弱。同时,确定恩施断裂的活动时间上限为20万a以上,重复活动的周期较长,对附近水电工程建设不会产生重大危害。

关键词: 断裂带, 工程地质, 湖北