Abstract:In order to use rockfill dam¢s adaptable predominance over topographical condition,and to reduce the excavation volume of overburden under the dam,concrete face rockfill dam(CFRD) designed on the strip mountain ridge is filled fitting the natural side,which makes the original massif be parts of the dam body,thus a fairly rare fitting-slope CFRD is achieved. Stress concentration tends to happen in the contact zones between rock slope and rockfill material,and the displacement of downstream part of dam is usually great,which usually leads to slipping of fitting-slope CFRD and to the decrease of the safety of CFRD. A new idea,ledge excavation of rock slope,is suggested to solve this complex problem. Comparison between the stress-deformation behavior of dam with ladder type rock slope and that of dam with line type rock slope has been made by using two-dimensional finite element numerical analysis. The calculation result shows that the displacement of dam with ladder type rock slope is much less than that of dam with line type rock slope. So ladder type rock slope is probably reasonable,especially for fitting-slope CFRD. At last,the influence of angle of excavation slope on dam¢s deformation and stress is discussed.