A semi-empirical relationship for predicting earthquake-induced crest settlement of concrete faced rockfill dams

In this study, the influence of seismic load characteristics including amplitude, period/frequency contents, and duration on the response of concrete face rockfill dams (CFRDs) was examined. The significant role of the tuning ratio, which is the ratio of a dam's natural vibration period to the predominant period of an earthquake, on the seismic crest settlement was investigated. The case histories of existing CFRDs were analyzed and a new index, as an appropriate intensity measure, was defined to quantify the severity of ground motions as a function of the tuning ratio. A semi-empirical relationship for predicting the earthquake-induced crest settlement was also proposed using a database of CFRD cases. The proposed approach links the ground motion parameters, dynamic characteristics of a dam, and the observed seismic crest settlement. The proposed semi-empirical relationship addressed the limitation of existing approaches by considering the resonance effect on the crest settlement. The validation of the proposed relationship was carried out using the observed data in CFRD case histories and the data obtained from numerical simulations of a typical case CFRD.