This paper summarizes our activities for elucidation of dynamic characteristics of super high-rise residential buildings during the 2011.3.11 Tohoku Earthquake and for mitigation of seismic damages during the future massive earthquakes. We organized the "Joint Study Group on Earthquake Observation Records in Super High-Rise Residential Buildings" after the 3.11 Earthquake, where we share information and the outcomes from the analyses of the recorded motions. In addition to that, we carried out questionnaire survey for residents, simulation analyses, mictrotremor measurements, shaking table tests, etc, toward comprehensive understanding of what happened during the 3.11 Earthquake. The obtained results will be available for mitigation of seismic damages during the future massive earthquakes. We must emphasize, last but not least, that strong motion observation in building is inevitable in terms not only of post-earthquake damage evaluation, but of services for residents in related with the life continuity planning.

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We review the current status and problems of the large-scale complex disaster in megacity, which are caused by earthquakes and floods. First, we review the recent evaluation on the occurrence probability of M7 earthquakes under the Tokyo metropolitan area, and compare the historical damage with the damage estimated by the national and local governments. Consequently, we conclude that the possibility of large-scale disaster due to the next M7 earthquake would be very low. On the other hand, we have to prepare for an unprecedented large-scale complex disaster, because of the coincidental multiple events by earthquake and flood. As examples, we investigate possible complex disasters in the areas around the Shinjuku and Kita-Senju stations, and propose various methods realization of resilient buildings and areas in megacity.

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According to damage estimation report by local governments and the government, post-earthquake urban fire spreading will occur necessarily and cause huge amount of not only physical damage but casualties. Post-earthquake urban fire has been main issue for disaster prevention since starting to take countermeasures for disaster prevention more than fifty years ago. The situation of urbanized area has changed. The performance of fire proof in urbanized area has increased apparently, however, urbanization has expanded broadly and made huge area of high dense built-up area. And then basic awareness and ability of people for fire incidents has become weak apparently. As for urban plan for post-earthquake fire prevention. Tokyo metropolitan government has implement surely. This paper mentions how post-earthquake fire risk and casualties caused by them shown in a report of earthquake damage estimation should be understood and discusses challenges we should do in the near future to make risk decrease.

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Simple evaluation of the degrees of structural damage suffered by high-rise RC buildings after being subjected to long-period strong ground motions is extremely important to the development of life continuity planning for building residents. However, these evaluations cannot be based on seismic and microtremor records because these observation equipment's are not installed in most such buildings. In an effort to address this situation, this study showed that the mean value of a periodic band (1.25T_0˜2.25T₀, where T₀ is initial natural period) in the pseudo velocity response spectrum (pSv) of input ground motions was effective as an index for presuming the degrees of structural damage of the buildings. To calculate the elasto-plastic responses of a SDOF model equivalent to the buildings due to the predicted long-period ground motions by a scenario Nankai earthquake, the dynamic properties of the buildings based on the strong-motion records for the 1995 Great Hanshin Earthquake (Mw 6.9) and the 2011 Great East Japan Earthquake (Mw9.0) were applied to a skeleton curve of the model.

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In this study, Adachi-ku Senju district in Tokyo was selected as an investigated district because this district has been designated by the Tokyo Metropolitan Government as an area having high fire and flood risks. Questionnaire survey was conducted for the residents in this district to collect data on level of recognitions of the residents about damage estimates of this district and recommended evacuation method. Moreover, stated preference for disaster evacuation was also surveyed. The obtained stated preference data was utilized to estimate disaster evacuation behavior model containing three kinds of models using nested logit model. The models were utilized to estimate the number of evacuee under different disaster situations.

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Tokyo Metropolitan area has high risk of the Tokyo Inland Earthquake in the future. In case of the earthquake, disaster base hospitals have missions to accommodate heavily injured victims and provide medical treatment for them. According to the lessons from past disasters, rapid transportation of heavily injured victims to disaster base hospitals and immediate medical treatment are very important to avoid their “Preventable Death”. In this research, needs for transportation of heavily injured victims to hospitals was analyzed considering the effect of traffic congestion, street blockades, fire to transportation based on road network. The maximum transportable area where victims could be transported to some hospitals by car within certain time was defined as“Accessible area to hospital”. This analysis identified the areas where rapid transportation to the nearest disaster base hospitals was impossible in case of the earthquake. Through the result of these analyses, several disaster medical response plans were proposed considering different disaster situations.

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This paper surveyed on intention to evacuation of residents and commuters in case of earthquake, flood, complex disasters in Senju area, Adachi ward in Tokyo which has high risk of these disasters. The survey identified the understanding of locations evacuation centers is insufficient in spite of high perception of these disaster risks. It also verified that people have different intention to evacuation according to building conditions of their residents and offices or disaster situations. Consideration of these facts in evacuation planning is required.

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We applied a proposed procedure for estimating the potential direct economic damage and death toll caused by multiple disasters of earthquakes and floods to a case study river, and extracted characteristics of effect of damage reduction measures against the multiple disasters. We assumed a multiple disaster in which a flood occurs after an earthquake, and estimated the potential damage in a river (about 60 km long). We estimated each damage in 120 cases changing the scale of the earthquake and the flood, the interval between the earthquake and the flood, and the countermeasure, considering the emergency works for the levees and roads, and the emergency rescue activities after the earthquake, and so on. We extracted 3 consideration points, which are beneficial for discussing possible damage reduction measures against the multiple disasters.

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The aim of this study is to develop a technique of searching the optimal evacuation route in real-time, at a huge earthquake, employing Ant Colony Optimization (ACO) which is one of the metaheuristics techniques. After a severe earthquake in a city area, quick refuge to temporary or extensive evacuation area should be required occasionally. However, the occurrence of building collapse and/or fire gives the serious problem with being impossible to utilize the preexisting route to evacuation area. In addition, it happens that the re-movement to the second refuge is compelled by the fire occurrence of the first refuge. In such a case, another evacuation route should be reconsidered. But due to numerous routes to be reexamined for the optimal route, it is very difficult to find it on time. In order to overcome the difficulty due to numerous routes, this study examined the optimal route search by coupling technique through ACO and backtracking method. As a result of the numerical calculation, computation time by ACO shows excellent reduction effects with around 1/100, as compared to calculating all the combination of routes. These results show that the proposed method based on the ACO technique is a useful one in searching the optimal evacuation route in real-time.

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In this paper, we built "Evacuation Simulation in Metropolitan Area" for the Tokyo Metropolitan Area. The simulation can evaluate policies for stranded commuters and provide several risk maps of heavy traffic in catastrophic disaster, using decision making model and movement data in the Tokyo Metropolitan Area on the Great East-Japan Earthquake. As a result, if catastrophic disaster occurs and everyone goes home all together in metropolitan area, we calculated that heavy traffic will overload the trunk lines for many hours in wide area and huge people(for example, six people in a square meter) along some sidewalks.

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An education and training program designed to improve the response literacy in the event of a large-scale earthquake in the Shinjuku station area in Tokyo was presented. And an actual disaster response exercise in 2013 for response to many people injured at high-rise buildings in the area was reported. The activities of the Shinjuku Station Area Disaster Response Measure Committee, made up of businesses and other concerns located in the vicinity of Shinjuku station, as well as the education and training program in fiscal year 2013 implemented by the committee to train personnel are introduced. The report then describes summary of the comprehensive disaster preparedness drill and details of the drill for response to many people injured, which was conducted in collaboration of businesses, healthcare professionals and other concerns to operate effectively.

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Proposal of building damage confirmation and information collection method of self-defense fire organization after an earthquake for multi-tenant high-rise building, development of some building damage check sheet and mobile tool that can be used in non-construction expert. First, it showed the position of research within a few hours from disaster on compare the main method of building damage confirmation after an earthquake. Then, suggest of damage confirmation flow after an earthquake by office tenants and facility manager. In addition, some building damage check sheet and mobile tool were developed for building damage confirmation and information collection. Then, contents of the drill were evaluated by questionnaire survey to the drill participants. Finally, major issues were shown according to results of the drill and opinion of participants.

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In Urban Renaissance Safety Security Plan in Shinjuku-Nishiguchi region, Nishiguchi local headquarters plays an important role. In this paper, the role and functions of the local headquarters, were subjected to verification by comparing international standards(ISO22320) and drill. The verification in this study enabled to clarify the direction of future challenges and order to promote the area disaster prevention activities based on Urban Renaissance Safety Security Plan.

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A killer earthquake with M7.3 would attack the metropolitan area in near future. This would result in 23,000 deaths (16,000 due to fires and 6,400 due to the building collapses and so on) and disorder of railroad traffic including Shinkansen and subways for one week, and Japan National railways and private companies ones for one month. On the other hand, Tokyo Olympic games will be held for two weeks in 2020. I discuss what kind of things will occur if the earthquake occurs just in time or before the Olympic games.

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