A CASE STUDY ON 3D NON-LINEAR ANALYSIS OF A CLAY CORE ROCKFILL DAM

Abstract

Claycore rockfill (CCR) dams are commonly used and the chosen model damconstruction due to their low cost and rapid construction advantages; moreoverplaying a key role in national water and power management systems. In terms oflarge water reservoir impoundment behind a high dam, they include a risk to thepublic, in case of an earthquake, especially for urban areas. Therefore, thestability of dam embankment and analysing seismic safety is of great concern togeotechnical engineers. In fact, these analyses are complex issues whichconcern both elastic and dynamic effects on the influence of the seismicresponse to real earthquake records. The objective of this study is to evaluatethe three dimensional static and dynamic degrading behaviour of a CCR damthrough using the finite difference method. The static part of the analysisconsiders the layered construction, reservoir impoundment and verticaldisplacements whereas, the dynamic part considers the response of the damto a real earthquake recording which represents the typical measures of a peakground acceleration (PGA) of the study area. Dams should be designed inconsidering an extreme earthquake with maximum intensity values. In view ofthis we have investigated the 3D non-linear seismic behaviour of a CCR damwhich was subjected to the 1999 Mw 7.1 Duzce earthquake and this is consistentwith the idea of an extreme earthquake of about maximum intensity in structuralseismic response analysis. The mechanical behavior of the dam material wasdescribed using the Mohr–Coulomb failure criterion. Dynamic analyses of themodel are performed and the dam behaviour and possible failure phenomenapresented. Discussions and comparisons between the non-linear simulationresults and existing parameters are expressed.