The earth-rock dam with clay core of Shenyugou dangerous reservoir in Fang County is studied

whose seepage and dam slope stability are evaluated

aiming to provide strength design with reference. Three kinds of stable seepage computing conditions such as check flood water table

designed flood water level and normal storing stage are designed and computed. Two types of unstable seepage schemes

from check flood water table to normal storing stage and lowering from normal storing water table to dead water level

are done. Moreover

five kinds of lowering velocities are designed by the latter unstable seepage scheme. Slope stability of dam is calculated at each seepage step. It is found that stability of downstream dam slope doesn’t meet to the engineering requirement under three stable seepages’ and two unstable seepages’ conditions. So the reservoir is a dangerous one

and is in need of strengthening