Head of the Ground Vibration Division at PWRI, supervised the project. This report is a copy of the draft report submitted to PWRI at the conclusion of my stay in Japan and provides a record of my research activities there. The objective of my research at PWRI was to determine the effects of topographic amplification of earthquake shaking on slope stability, particularly in the case of large, deep-seated landslides. The massive debris avalanche from the south flank of Mt. Ontake triggered by

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... 1984 Naganoken-Seibu earthquake was investigated as a possible case study of topographic amplification leading to slope failure. This study required synthesis of research on several subjects: 1. A method was developed to estimate the relative dynamic performances of slopes having different dynamic stabilities and experiencing different levels of seismic shaking. 2. Findings from other investigations of topographic amplification were analyzed for comparison with each other and with findings from the present research. Data from seismic site-response experiments in Chile and Japan were examined in detail. 3. Results of shaking-table tests on silicon slope models, conducted at PWRI in 1987, were analyzed and compared with the results of the field studies mentioned above and to the Mt. Ontake debris avalanche.