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In this paper, we study the influence of ground motion predicted for Uemachi Faults to the response of highrise buildings. Two highrise buildings were modeled to fishbone-shaped frame model and time-history analysis was performed. Then, we compared response of fishbone-shaped frame model with response of other vibration models.Also, we studied the influence of PΔ effect. As a result, the following conclusions are obtained. 1) The response to the predicted ground motion is much larger than that of the seismic design motions. 2) It tends to evaluate the response small in a more detailed vibration model. 3) When the first mode response is predominant, the influence of PΔ effect is large.

A simple method for estimating the seismic amplification characteristics of surface strata is proposed by using the response spectrum method within the capacity-spectrum design scheme. The following presentations and discussions are made in this article: 1) to compute the natural and equivalent site periods based on the modal analyses of the multi-degree-of-freedom (MDOF) soil systems, 2) to determine the effective shear strain in surface soil, and 3) to examine the reliability and accuracy of the proposed method compared to SHAKE analysis.

The Kiragawa-cho in Muroto city, Kochi prefecture, which will be the most heavily damaged area in the next Nankai earthquake, is selected to consider how to reduce the earthquake damage of traditional wooden houses in the important district of groups of historic buildings. A questionnaire survey for local residents and evaluation of seismic capacity and durability for existing houses are performed. As results, the following conclusions are obtained. 1) Some houses have poor seismic performance. 2) It is possible to identify vulnerable houses by microtremor measurements. 3) Long term measures accordance with a whole life design of residents is necessary for houses in this districts.

The system identification of the dynamic properties such as natural periods and damping ratios of four skyscrapers located on Osaka plains was conducted based on the observation records during South-east off Kii-peninsula earthquake September 2004 (M7.4). We found the dynamic properties in the large amplitude portions of response waveforms to be longer in natural period for all buildings and larger in damping ratio for a few steel-buildings than those in the onset and/or the terminal portions of response waveforms. The greatest coefficients of variation of natural periods in duration of response seismic motions were 2 to 4 percents for steel-buildings and 8 percents for a reinforced-concrete building.

We conducted a questionnaire survey on damage of industrial facilities during the 2007 Niigataken Chuetsu-oki Earthquake to examine the relationship between seismic intensity and damage of facilities. We also investigated the cause of functional damage comparing a period of restoration of various damaged parts to those of functional cessation. The following conclusions are obtained. 1) In the JMA seismic intensity over 5.5, various damage were occurred in many parts of facilities. Some facilities have shut down for a week or more. 2) The factor related to functional cessation varied corresponding to requirements for performance of the facility.

In this paper, vibration characteristics of 43 middle-rise reinforced concrete buildings located in Kyoto city were investigated based on microtremor measurements. The buildings can be divided to three types by judging from the structural specifications. The vibration characteristics of soil around the objective buildings were also investigated. As the influences of soil-structure interaction were evident, we used a model including swaying and rocking behavior of soil in the analysis. The natural frequencies of the three-type buildings were compared, and their statistical properties were evaluated.