Earthquake Disaster Mitigation Strategy Based on Seismic Simulation of Mega-City

在1995年的科比大地震中，11万多所房屋被毁，6,400多人死亡。大多数人是由于现有的低抗震房屋倒塌而丧生的。然而，有证据表明，如此多的预编码的房屋存在，公众对地震时的潜在损失的认识很低。更好地了解建筑物的抗震性能是必不可少的。解决方法之一是通过让公众了解地震时自己的城市如何摇晃以及自己的房屋发生了什么，来鼓励公众加强自己房屋的意识。在本研究中，我们提出了基于地震时结构地震模拟的地震减灾策略。因此，所得的估计结果是平均的，未必足以令公众信服。本研究提供一种利用三维地理资讯系统资料建立大量建筑物结构模型的方法，使建筑物结构的抗震分析成为可能。为了减少地震造成的人员伤亡，了解建筑物倒塌的过程以及人员的受伤情况是非常重要的。采用离散单元法分析了木结构房屋在地震作用下的三维倒塌特性。产出可用作风险沟通的有用工具。这些内容是开放给公众，可通过网站下载

In the 1995 Kobe Earthquake, over 110 thousand houses were destroyed and more than 6,400 people died. Most of the people were killed by the collapse of existing low earthquake-resistant houses. However, evidences show that so many pre-code houses exist and the public awareness of potential losses during earthquakes is low. Better understanding on seismic behavior of the building is indispensable. One of the solutions is to encourage public awareness for strengthening of their own houses by letting them know how their town shakes during an earthquake and what happens in his/her house.In this research, we proposed the earthquake disaster mitigation strategy based on the seismic simulation of structures during an earthquake.As the amount of total buildings in a city is huge, statistic approaches are commonly employed. Therefore, results of estimation obtained are in average and might not be sufficient in convincing the public. On utilizing 3D GIS data, this study provides a method of constructing structural models of large amount of buildings, which enables seismic analysis of building structures. Evacuation behavior under emergency situation also can be simulated.To reduce the casualty due to earthquakes, it is very important to know the process structures collapse and how the occupants get injured. Three dimensional behavior of the collapse of timber frame houses under seismic motion were analyzed by using Distinct Element Method (Fig. 3). Outputs can be used as a useful tool of risk communication. These contents are open to the public and can be downloaded through web-site