Simulation of collapse process of elevated expressway bridges due to the 1995 Kobe eathquake

ABSTRACT

At 546 a.m.(local time) on January 17, 1995, the Great Hanhin(Hyogoken-nambu or Kobe) earthquake hit the Hanshin-Awaji area, Japan. The damage due to this eartquake was the worst eartquake disaster in Japan since the 1923 Great Kanto earthquake. Over 100.000 houses and buildings collapsed and many modern civil infraestructures such as elevated bridges of highways and railways and port facilities, etc. were also heavily damaged. In addition, fires broke out razing many houses after the quake. The death toll was more then 6.400 including deaths due to various problems followint the earthquake. Unfortunately, mos deaths were caused due to collapse of structures. To mitigate casualties due to earthquakes, it is important to study the mechanism of collapse of structures during earthquakes. In this study, using the Extended Distinct Element Method(EDEM) wich is applicable to both a composite and continuous medium, and a perfect discrete one, the collapse mechanism of structures during the 1995 Great Hanshin earthquake is studied. Although the phenomena treated in this study were difficult to be simulated by the conventional methods such as the finite element method, the numerical results obtained agree well with the actual earthquake damage. (AU)