EARTHQUAKE RESPONSE OF ROCKFILL DAM WITH ASYMMETRIC PLAN GEOMETRY OF UPSTREAM AND DOWNSTREAM SLOPE WITH RESPECT TO DAM AXIS

摘要

Two-dimensional dynamic analysis for the maximum section of a dam cannot considerthe canyon effect, because it is carried out in the plane strain condition. Also, if the plangeometry of upstream and downstream slope is not symmetrical with respect to the damaxis, the results of 2-D analyses cannot accurately represent dynamic response of the damto earthquake. In this study, three-dimensional dynamic analyses for Miryang multipurposedam (concrete-faced rockfill type) in South Korea, with asymmetric plangeometry of upstream and downstream slope with respect to the dam axis, were carriedout and the response of the dam was analyzed. The results of 3-D dynamic analyses werecompared with those of 2-D plane strain dynamic analyses. It was found that themaximum settlement did not appear at the maximum cross-section and the magnitude ofmaximum settlement obtained by 3-D analysis was different from that by 2-D analysisfor the maximum cross-section. Furthermore, it was found that the characteristics ofacceleration amplification obtained by 3-D analysis were different from those by 2-Danalysis. This study presents an insight in the earthquake response behaviors of a rockfilldam with the asymmetric plan geometry of upstream and downstream slope with respectto the dam axis. It can also be used as fundamental data for seismic stability and designfor rockfill dams with asymmetric plan geometry of upstream and downstream slope.