Structural health monitoring attracts attention, as the technique of realizing quantification of the damage risk of building and civil structure. However, the cost spent on wiring had become the barrier which introduces a monitoring system to a large-sized structure. In this research, for wiring cost reduction, the wireless sensor network system which used TCP/IP and radio communications was proposed, and the theoretical analysis, prototype manufacture, and the evaluation examination were performed. The sensor network proposed in this paper satisfied the target performance. And it was able to reduce sharply the wiring cost and the time. Furthermore, it has attained the high synchronicity needed for real time damage detection.

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We introduce additional correction terms into empirical prediction for peak seismic ground motions from intermediate depth earthquakes, which cause anomalous seismic intensity in northeast Japan. Here two terms for the empirical attenuation relations of Si and Midorikawa (1999) were determined by using observed strong motion records of K-NET and KiK-net. First term corresponds to the difference of peak amplitudes between the fore-and back-arc side in the region. Second corresponds to low attenuation of seismic waves propagating long distance in high-Q slab. The regional bias due to abnormal Q structure in the subduction zone can be corrected by the both introduced terms. By applying these new terms to the original empirical attenuation relations, the distribution and accuracy of the predicted peak ground motions from an intermediate depth event are improved remarkably in wide area beyond 300km.

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