In order to examine the influence of void ratio and stress-path to the Soil-Water Characteristic Curve (SWCC) of unsaturated sandy soil, suction loading and unloading tests on the specimen with different stress-path and void ratio were implemented. As results, following facts can be made clear. Hysteresis of SWCC for initially dry specimen during suction-unloading and loading can be negligible. SWCC, the relationship between void ratio and suction, and the relationship between void ratio and the degree of saturation during suction-unloading, are not influenced by the stress-path of the specimen. Void ratio seems to give no influence to the slope of SWCC, while the minimum volumetric water content of SWCC seems to be constant.
It is necessary to carry out prompt and appropriate disaster management such as quick inspection of hazardous sites endangered by landslide and sediment-related disasters in order to minimize damages caused by landslide and sediment-related disasters in the immediate aftermath of earthquakes. Hydrological conditions can be described by the specific hydrological indices over a wide area, which have been proposed as applicable indices to Hokuriku region. Earthquake ground vibration is measured by seismometers provided for each local community nationwide using the Japan Meteorological Agency seismic intensity (JMA seismic intensity) . Thus, both hydrological conditions and earthquake motions can be obtained for each local community. Three salient earthquakes had struck Hokuriku region for the past three years. Quick inspection of hazardous sites and damage level assessments was carried out for local communities in the immediate aftermath. Damage level assessments showed where countermeasures were needed. This study is conducted to provide a practical guideline to have a prioritized quick inspection. In this study, those hazardous sites were analyzed using the hydrological indices and the JMA seismic levels. This analysis provides a basis for a methodology to estimate landslide risk of the hazardous sites in areas suffered strong motion with a certain level or higher JMA seismic levels. It is concluded that landslide risk of the hazardous sites can be estimated more rigorously by taking hydrological conditions over a wide area into consideration. The specific hydrological indices over a wide area are evaluated in comparison with hit rates and probability of detection in the estimation of hazardous sites.