SEISMIC RISK EVALUATION OF IRRIGATION TANKS: A CASE STUDY IN IBIGAWA-CHO, GIFU PREFECTURE, JAPAN

Landslides are one of earth’s most serious types of natural disasters and they are often induced by earthquakes. Predicting the approximate landslide displacements caused by earthquakes is helpful for assessing earthquake hazards and for designing slopes to withstand future seismic shaking. In this research, the authors firstly focus on obtaining the residual strength parameters and the peak strength parameters by multistage procedure with the Bromhead ring shear apparatus, which are used in the slope stability analysis. The maximum vertical settlement (MVS) of a slope is determined by the Newmark method using representative data from three earthquakes, i.e., Great Hanshin Earthquake, Chuetsu Earthquake and Iwate-Miyagi Nairiku Earthquake. It is experimentally demonstrated that the MVS is very large in both Tanigumi Pond and Sugo Pond. Once a great earthquake occurs, the progressive failure phenomenon appears and people living in the area will be in danger. The results presented in this paper can be applied to future landslide hazard assessments and used to promote reconstruction efforts by the government in the affected areas and for future disaster prevention and mitigation.