2026 Volume 63 Issue 3 Pages 93-108
Earthquake-resistant structures have been severely damaged by landslides induced by earthquakes. Consequently, these structures could not successfully achieve the targeted safety criteria. Hence, methods to reduce the risk (probability×vulnerability×loss) of slope failures, adjacent to earthquake-resistant structure, require due consideration. While past investigations indicate that countermeasures can restrain coseismic landslides, criteria for the targeted performance of countermeasures are yet to be developed. We assessed the criteria and procedures to evaluate the performance of countermeasures in terms of reduction of exceedance probability (PN), through dynamic simulations of a model slope with and without countermeasures. The model represents a case where resistance is lost due to seismically induced excess pore pressure (Pex). The intensity of the seismic response at the threshold of mobilization is expressed by peak ground velocity (PGV). PN, corresponding to the PGV, was obtained from the earthquake hazard curve of the National Research Institute for Earth Science and Disaster Resilience. Although the possible range of PN may be large, the countermeasure which reduces Pex, showed a clear positive effect in reducing PN.
