Determination of Non-uniform Input Ground Motion for High Concrete Face Rockfill Dams

Abstract

A method is developed in this study to determine the non-uniform input ground motion based on seismic records for the seismic analysis of high concrete face rockfill dams (CFRDs). The acceleration time histories recorded during the 2011 Tohoku earthquake at the Haga station is used as an example to determine the potential functions of the seismic waves. The recorded surface acceleration time history and calculated non-uniform input are then used to conduct analysis of the seismic response of the Gushui CFRD under both uniform and non-uniform input motions. Under the condition that the acceleration time histories on the surface of the free field are assumed to be the same for non-uniform and uniform seismic input, the seismic response of the CFRD under non-uniform input is found to be in general significantly smaller, while the local dynamic stresses around the edges of the concrete face slab are greater. The analysis results suggest that non-uniformity of the ground motion input has important effects on the seismic response of high CFRDs, and should be considered in the seismic design of CFRDs.