Seismic probabilistic risk estimation of Japanese railway embankments and risk-based design strength of soil and reinforcement

For the rational seismic design of railway embankments considering seismic risk, high-strength geomaterials and reinforcements should be used in areas with high seismic probability, and low-strength geomaterials and re-inforcements should be used in areas with low seismic probability. In this study, a seismic probabilistic risk estimation of Japanese railway embankments was conducted using publicly available information on seismic hazards in Japan and previously estimated seismic-fragility curves for Japanese railway embankments. To determine the required average friction angle of backfill soil and average reinforcement tensile strength for satisfying the prescribed allowable seismic risk, a sensitivity analysis of the railway embankment was conducted by changing the average friction angle of the backfill soil and the average reinforcement tensile strength. Using the sensitivity-analysis results, the required average friction angle of the backfill soil and average reinforcement tensile strength of the railway embankment satisfying the prescribed allowable seismic risk considering the occurrence probability of earthquakes were analytically obtained.