Journal of Japan Association for Earthquake Engineering
Online ISSN : 1884-6246
ISSN-L : 1884-6246
Volume 20 , Issue 3
Special issue: The 15th Japan Earthquake Engineering Symposium (4)
Showing 1-8 articles out of 8 articles from the selected issue
Technical Papers
  • Takashi HAYAKAWA, Akihiro SHIMMURA, Kazuhito HIKIMA, Tomiichi UETAKE
    2020 Volume 20 Issue 3 Pages 3_1-3_20
    Published: 2020
    Released: March 27, 2020
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    The seismic ground motion records observed in the Kashiwazaki-Kariwa Nuclear Power Station were used to evaluate a regional three-dimensional velocity structure model that would be used for long-period ground motion prediction. First, the velocity structure model evaluated by the National Institute of Advanced Industrial Science and Technology was modified by incorporating the underground structure information obtained by geophysical exploration of the site and surrounding area. Next, the earthquake ground motions with a period of more than 2 seconds due to medium or small earthquakes occurred near the source regions of the huge scenario earthquake were simulated by the three-dimensional finite difference method. The effectiveness of the modified model was evaluated by the reproducibility of the waveforms and the response spectra.

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  • Tomoki HIKITA, Kazuki KOKETSU, Hiroe MIYAKE
    2020 Volume 20 Issue 3 Pages 3_21-3_34
    Published: 2020
    Released: March 27, 2020
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    In order to evaluate the variability of predicted ground motion amplitude due to aleatory uncertainty of the source parameters, we conducted ground motion simulation considering the uncertainty of the source parameters. Since the characteristics of the variability of simulated ground motion amplitude are consistent with the variability investigated by analysis of ground motion records (Hikita et al., 2018), the uncertainty of the fault parameters assumed in the simulation is reasonable. The characteristics of the variability of simulated ground motion amplitude varied according to the seismic magnitude. In the simulation for MJ7.0 earthquake, the variability of simulated ground motion amplitude of about 2 seconds in period was relatively large.

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  • Taro ISHIKAWA, Kimitoshi SAKAI, Kazunori WADA, Yoshitaka MURONO, Kenic ...
    2020 Volume 20 Issue 3 Pages 3_35-3_50
    Published: 2020
    Released: March 27, 2020
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    At first, it is confirmed that the damping ratio calculated by the strain energy proportional damping method is consistent with the damping ratio evaluated from the microtremor observation of the single column pier. Next, we evaluated the damping ratio of the various type of railway viaducts analytically and proposed the evaluation method of the damping ratio based on the amplitude ratio of underground part to entire structure which is calculated from the primary vibration mode shape. Furthermore, we proposed the evaluation method for seismic nonlinear response of railway viaducts by using the proposed evaluation method of the damping ratio. The nonlinear seismic response considering the proper damping ratio can be obtained by using this method, and the calculation procedure is almost the same as that by using the conventional method. Therefore, this method is effective for evaluating the seismic response of railway viaducts for the seismic design.

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  • Akane SHINODA, Shigeyuki OKADA, Tadayoshi NAKASHIMA
    2020 Volume 20 Issue 3 Pages 3_51-3_69
    Published: 2020
    Released: March 27, 2020
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    Governments estimate earthquake damage affected by only the main event of an earthquake. However, the damage is amplified by aftershocks and subsequent cyclic events. From the point of view of disaster protection where estimation of full extent of the damage is important in canceling evacuation order, we propose an evaluation method for degrading seismic resistance of wooden buildings exposed to cyclic events using seismic capacity grade. The object region is Ojiya City and the event is Niigata Prefecture Chuetsu Earthquake of 2004. It is revealed that the ratio of degrading seismic resistant performance is larger in large intensity, small seismic capacity grade buildings and that the probability of amplified damage is larger in large intensity. The proposed approach is applied to Sapporo City, and the number of damaged buildings, deaths and recovery cost with each correspondence after the main shock are simulated.

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  • Gaku SHOJI, Chihoko NAKAJIMA, Kento YOSHINARI
    2020 Volume 20 Issue 3 Pages 3_70-3_83
    Published: 2020
    Released: March 27, 2020
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    The seismic damage data of flat roads subjected to strong ground motions and liquefaction in the 2011 off the Pacific coast of Tohoku earthquake were analyzed and the fragility curves describing the probability of occurrence of a failure to flat roads were derived based on probabilistic modeling. Flat roads distributed in a seismically potential liquefied area have a risk to show the relatively higher value of damage-ratio index when PGV of 30 cm/s or instrumental seismic intensity, IJ of 5.0, that is the relatively lower value of seismic intensity.

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  • Shin-ichi YOSHIDA, Masahito AKIMOTO, Takao ADACHI, Tsutomu OGAWA, Masa ...
    2020 Volume 20 Issue 3 Pages 3_84-3_95
    Published: 2020
    Released: March 27, 2020
    JOURNALS RESTRICTED ACCESS

    As is the case with other natural phenomena such as seismic motions and tsunamis, the influence on the facilities by the permanent displacement of the ground is evaluated appropriately considering its uncertainty which is evaluated by hazard analysis. And, mitigation measures should be taken in accordance with the evaluation result. In this paper, trial analysis where fault displacement is input at the lower surface of the base slab of a PWR type reactor building is performed. In this analysis, structural safety is assessed by using nonlinear finite element models of reinforced concrete members such as the base slab of the reactor building.

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