The 2018 Hokkaido Eastern Iburi Earthquake occurred around 3:07 on September 6, 2018. The maximum seismic intensity of 7 was observed in Atsuma-chou. A seismic intensity of 7 was observed in Hokkaido for the first time. Due to the influence of this earthquake, the whole Hokkaido was blacked out on the day of the earthquake occurrence. In addition, all flights were canceled at New Chitose Airport, which was hit by a strong shake of seismic intensity of 6 upper. In this study, a web based questionnaire survey was conducted for New Chitose Airport users who did not live in Hokkaido at the time of the earthquake by the authors. This questionnaire survey was about the travel behavior, collecting the information regarding transportation during the disaster and so on. It became clear that travel behavior, method of collecting information about traffic condition and purpose of returning home outside in Hokkaido during the disaster.

The distributed power resources such as solar power generation connected to electrical distribution network are increasing with the support of the feed-in tariff of renewable energy. They are expected to remedy the electric power interruption caused by the accident of the distribution facilities and the natural disasters. On the other hand, in an event of earthquake disaster, there is a high possibility that the power users are damaged, and the power demand is assumed to be lower than normal demand. Understanding the decline in power demand due to the effects of distributed power resources and users' damage is a necessary issue in making decisions on disaster prevention measures for distribution facilities. In this paper, an evaluation method of the electric power interruption due to an earthquake disaster considering the users' damage and effect of distributed power resources is proposed. In addition, we consider the distribution lines parallel-off due to the voltage fluctuation in the artificial initial response when an earthquake occurs, and statistically estimate the fragility curves for the distribution lines based on observation data in the Kumamoto earthquake (April, 16, 2016, M7.3). The JST-CREST 126 system model is adopted as example of the distribution network and the improvement effect of the electric power interruption by the distributed power resources are discussed for applicability of the proposed method.

Recently, asset management systems have become the powerful tool that is able to lead to an effective maintenance strategy of civil infrastructures. In the system, it is important to estimate the deterioration of infrastructures. However, there are few studies of deterioration prediction considering event risk such as earthquakes. This paper proposes the simplified dynamic macro deterioration prediction model of a set of tunnel lighting facilities that considers seismic damage ratio to them in addition to natural deterioration. Concretely, the model treats all tunnel lighting facilities in a tunnel tube as one unit and predicts health degree of a tunnel unit. Then, the paper estimates the restoration cost and the restoration health degree using the indicator of cost-effectiveness degree in the case of immediate restoration. Finally, the authors discuss the applicability of the proposed asset management model from cost management point of view.

We propose an empirical formula expressed by using indices of microtremor H/V in order to easily evaluate an amplification factor for peak ground velocity in consideration of an effect of input motion spectra for bedrock. Firstly, an empirical formula model for an amplification factor consisting fundamental peak frequency and peak amplitude is derived based on a theoretical model proposed by authors. It is found that the empirical formula can accurately evaluate the amplification factors. Next, a formula for amplification factors evaluated from observation records is obtained by using parameters of site effect. The observed amplification factors show strong correlation to the ones evaluated by the formula. Finally, we develop an empirical formula by using a microtremor H/V instead of the site effect. Consequently, it is clarified that the empirical formula can evaluate the observed amplification factors more accurately than the formula model in the past studies.

To raise public awareness of disaster prevention, we consider the use of an educational device, which gives earthquake experience, is effective in addition to emergency drills. We had developed a self-propelled earthquake vibration generating device, on which people can have earthquake experience. In this development, we have developed a new carriable earthquake vibration simulator for easy vibration experiments and visualization of various vibrations, which depend on the natural frequencies of buildings. This platform is designed to be smaller and lighter by having a lighter payload of about 10 kg, which is lighter than that of an existing platform. Also, this platform can generate two-dimensional vibration at 3 Hz to 10 Hz, which was difficult when using the existing platform. In this development, we have adopted two new mechanisms: a blade-type omni wheel for high gripping force on a floor and an omni-directional acceleration generating mechanism with twist radial configuration omni wheels to run on omni direction with high agility. In this paper, we report the design requirements and the functionalities, the configuration of the prototype, and the result of our experiments.

We carried out damage investigation around the seismic stations where high JMA seismic intensity scales were recorded in the 2018 Hokkaido Eastern Iburi Earthquake. Heavily damaged buildings were found around K-NET Mukawa, but no heavily damaged buildings were found around the other seismic stations. We investigated the correspondence of the strong ground motions with damage to buildings. The strong ground motion that was observed in K-NET Mukawa has large 1-1.5 sec. response, the response in the period range of 1-1.5 s, which has close relationship with heavy damage to buildings. Short-period below 1 sec. was dominated and 1-1.5 sec. response was small in the other strong ground motions.