지진 시 산사면의 영구변위 추정식 개발

초록

Empirical seismic displacement equations based on the Newmark sliding block method are widely used to developseismic landslide hazard map. Most proposed equations have been developed for embankments and landfills, and donot consider the dynamic response of sliding block. Therefore, they cannot be applied to Korean mountain slopescomposed of thin, uniform soil-layer underlain by an inclined bedrock parallel to the slope. In this paper, a seriesof two-dimensional dynamic nonlinear finite difference analyses were performed to estimate the permanent seismic slopedisplacement. The seismic displacement of mountain slopes was calculated using the Newmark method and theequivalent acceleration time history. The calculated seismic displacements of the mountain slopes were compared toa widely used empirical displacement model. We show that the displacement prediction is significantly enhanced ifthe slope is modeled as a flexible sliding mass and the amplification characteristics are accounted for. Regressionequation, which uses PGA, PGV, Arias intensity of the ground motion and the fundamental period of soil layer, isshown to provide a reliable estimate of the sliding displacement. Furthermore, the empirical equation is shown to reliablypredict the hazard category.

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