This paper examined the effect of aging on the deterioration of structural members and joints on the earthquake response of a traditional Japanese wooden temple, Kiyomizu, in Kyoto. First, the effect of deterioration at the beam-column joints was studied. Push-over analysis and nonlinear earthquake response analysis showed that deterioration of the beam-column joints decreased the bearing load capacity, especially in the E-W direction, and increased the response displacement of the temple. Next, the effect of deterioration due to age of the structural member was studied. The structural members of Kiyomizu temple are made of 350-year old zelkova wood, the Young's modulus of which decreases continuously once it is used as a structural member. Static and dynamic analyses showed that the deterioration of Young's modulus decreased the bearing load capacity and increased the displacement response of the temple. However, the risk of total collapse is considered to be low if the deterioration ratio of the modulus is linear.

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The relationships between average shear-wave velocity of the ground and the site amplification factor for peak ground acceleration, peak ground velocity, seismic intensity and response spectral amplitudes are examined by using the strong motion records from the Yokohama Dense Strong-Motion Network. Regarding the amplification factors for peak ground acceleration, peak ground velocity and seismic intensity, the results by the records from smaller magnitude earthquakes and from larger magnitude earthquakes are different. This is due to the different spectral contents of the records from smaller and larger earthquakes. The amplification factors for peak ground acceleration, peak ground velocity and seismic intensity show higher correlations with the average shear-wave velocities of the ground down to 10m, 30m and 20 to 30 m, respectively. The amplification factors for response spectral amplitudes for shorter, mid and longer periods show higher correlations with the average shear-wave velocities of the ground down to 10m, 20m and 30 m, respectively. The correlations of the spectral amplitude at longer period range are higher than those at shorter period range.

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Many spent fuels coming out of the nuclear power station are planned to be stored in the special site in Japan until they are reprocessed. In this site, the spent fuels are installed in a cylindrical container called canister. And the canister is installed in the outer cylinder called cask which is a free-standing structure. Therefore, it is very important to reduce the seismic response of the cask at the seismic event. In this study, the sliding and rocking motions of a cask are evaluated analytically. In an analytical model, the cask and the canister are treated as rigid bodies which are connected by a spring, because the cask and canister system is seen as a two-degree-of-freedom coupled system. The equations of motions are derived for sliding and rocking motions when the floor is subjected to the horizontal excitation. The displacement and the rocking angle of the cask are evaluated by numerical simulations. The effects of the canister vibration on the cask motion are discussed.

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The aim of this paper is to examine the mechanism attributing to re-liquefaction. We observed the distribution of sand boiling from the model ground with a series of shaking table tests. The test results show that sand boiling tends to occur at the same place repeatedly as before. We then conducted shaking table tests to measure the shear resistance distribution along the depth in the model ground with a hand vane apparatus. The shear resistance of sand deposit after liquefaction was found to increase only at the bottom part of the model ground. The reason of the non-increase or decrease of shear resistance from the surface to a critical depth was considered to be caused by the upward seepage flow. The shear resistance of sand deposits subjected to a quick sand condition in the seepage tests was found to be similar to those in shaking table tests. Based on the experimental results, the repeated occurrence of liquefaction can be believed to occur due to the disturbance provided by upward flow, which prevents the increase of density of liquefied sand from occurring during the process of dissipation of pore water pressure after liquefaction.

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Two down-hole array strong-motion digital records on IC-memory cards at the Kashiwazaki-Kariwa Nuclear Power Station of Tokyo Electric Power Company during the main shock of the 2007 Niigata-Chuetsu-oki earthquake (Mj=6.8) were overwritten by succeeding aftershocks due to the less memory-capacity of the recording system. However, the monitoring pen-writing records were remained; therefore, we tried to retrieve the waveforms during the main shock by digitizing the pen-writing records using a CAD system and we prepared the report for estimating the strong-motions at some down-hole sites.

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We carried out damage investigation around the seismic stations where high JMA seismic intensity scales were recorded in the 2007 Noto-hanto Earthquake. We found heavily damaged wooden houses around all the stations with 6+JMA scale. The ratios of heavily damaged wooden houses were about 20% around the K-NET Anamizu and Monzenmachi, Wajima city Shindokei, but almost all the heavily damaged wooden houses were very old ones or stores with large openinngs in the first story. We found no heavily damaged wooden houses around the stations with 6-JMA scale exept for K-NET Wajima. We found no heavily damaged non-wooden buildings around all the stations. Strong ground motions which have various kind of period characteristics were observed in this earthquake. In particular, 1.5-2 sec. dominated recored was observed at JMA Wajima for the first time as the site with building damage data. Correspondence of strong ground motions with damage to buildings can be roughly explained by the 1-2sec. response which the author proposed as the index representing damageability of strong ground motions. However, in the case of JMA Wajima which had 1.5-2 sec. dominant period, we found some difficulty to explain the actual damage to buildings by the index.

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