A methodology for detecting slope failure areas from high-resolution satellite images and digital elevation model (DEM) is introduced and the applicability of the method is examined. The pre- and post-earthquake IKONOS images and the DEM observed in the epicentral area of the 2004 Niigata-ken Chuetsu earthquake (MJ6.8) are used. Slope failures are visually observed in the image since vegetations are flowed away and soils are exposed on the surface in most of slope failure areas. Difference of Normalized Difference Vegetation Index (NDVI) between the pre- and post-earthquake IKONOS images is used to evaluate slope failures. The areas where NDVI is remarkably decreased are extracted as slope failure areas. DEM is used to overlay the images precisely and to reduce mis-detection on flat areas. The distribution of the detected areas shows good agreement with the slope failure areas manually detected from the aerial photographs. Almost 85% of the slope failure areas are correctly detected in the analysis.

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The present paper examines the effect of floor stiffness on the earthquake response of Kiyomizu temple, a traditional Japanese wooden structure that was rebuilt in 1633. Although the floors of traditional wooden structures are generally not considered to be rigid, a large open stage attached to the main hall of Kiyomizu temple may function as a horizontal diaphragm similar to a semi-rigid floor. Therefore, nonlinear earthquake response analyses were conducted using a semi-rigid floor model and a non-rigid floor model in simulations of the Hanaore fault earthquake and the Tonankai earthquake. The results indicated that the non-rigid floor assumption tended to overestimate the response of the stage structure. Thus, the horizontal stiffness of the floor affected the estimation of the seismic performance of the main hall with the stage. In contrast, the horizontal stiffness of the roof was found to have little effect on the evaluation.

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It is expected that damages of transportation system including highway bridges cause serious interference of traffic function and recovery efforts, when a large earthquake occurs to a densely populated urban area as it was happened during the great Hanshin Awaji Earthquake in 1995. Therefore, the real-time earthquake damage detection system for bridge structures seems to be necessary to provide information of damages in transportation network system just after the occurrence of the earthquake and to assist the damage reduction, prevention of damage expansion and recovery works. This research proposes the method of evaluating the damages of bridge pier to provide useful information for real-time earthquake damage detection system by using Neural Networks technique. In this study, the emulator was constructed first to express intact structure by using Neural Networks. Then, it was examined whether the difference between output of the emulator and measured response of the bridge pier showed the damages of the bridge structure. Dynamic experimental data which were acquired at the shaking table test of RC single column conducted by Public Works Research Institute, Tsukuba, were used to verify the proposed method. Amplitude ratio and phase difference were selected to show the difference between output of the emulator and measured response of the bridge pier. As a result, it was confirmed that these two indices corresponded well to the damages, namely the change in the natural frequencies and the damping constant. The proposed method is able to provide the useful information for damages more quickly than frequency domain analysis method.

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We conduct a three-dimensional earthquake response analysis to evaluate the ground motion in the Kyoto basin from a scenario earthquake of the Hanaore Fault, in order to perform the seismic estimation of important cultural assets in the city. The analysis is based on a non-linear finite element method to calculate the non-elasticity of soil, and considers the multi-input of earthquake motion at the bedrock, and the wave propagation through an irregular underground structure. The results show that it is necessary to consider the source ground motion, wave propagation and soil response at each site simultaneously, for the purpose of the estimating the seismic ground motion on the surface of basin structure like Kyoto.

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