Message from the Director

Since its establishment following the 1995 Kobe Earthquake, E-Defense has conducted more than 120 shaking table experiments since it began operations in 2005. In the early stages, the experiments focused primarily on understanding the failure processes of structures and evaluating their seismic performance. Subsequent experiments expanded to address not only structural collapse prevention but also the evaluation and enhancement of post-earthquake functional continuity, structural resilience against collapse, and response control technologies designed to actively enhance such resilience. Additionally, E-Defense has conducted tests that emphasize the evaluation of collapse margins including both structural and nonstructural components. Parallel to these experimental efforts, the development of numerical simulation technology, referred to as the “numerical shaking table”, has also been pursued to analytically reproduce these phenomena.

It can be said that this series of research and development efforts has primarily focused on the response of a single structure to a single seismic event. In other words, the core of our work has centered on advancing the understanding of the individual, refining the behavior and performance of individual structures. The significance of this focus remains unchanged and fundamental. At the same time, however, as Japan faces the potential threat of large-scale disasters such as a massive Nankai Trough Earthquake and the Tokyo Metropolitan Earthquake, both of which could cause widespread and severe damage, the ability to quickly restore and sustain social and economic activities becomes critically important. To achieve this, there is no question that enhancing the resilience of entire urban areas, which are composed of diverse groups of structures, is essential.

In response, we have launched a new phase of research and development that focuses squarely on the urban scale, with the goal of directly contributing to the enhancement of urban resilience. This involves expanding our scope from individual structures to multiple structures within urban spaces, in other words, the city itself, and from a single seismic event to multiple seismic events that are likely to occur over the medium to long term, from the immediate aftermath of a disaster through to the recovery phase. Our aim is to uncover challenges and phenomena that have not yet surfaced but may emerge in future large-scale earthquakes. By forecasting future risks, we seek to contribute to prevention and early response. To support this goal, we are actively developing a range of technologies that will strengthen urban resilience in a comprehensive and forward-looking manner.

In addition to physical destruction experiments, the advancement of risk prediction technologies through numerical simulation will become increasingly important in the future. In particular, when extending our focus to the urban scale, it becomes essential to develop simulation technologies that operate in a cyber environment modeled on real cities. Our numerical shaking table, which functions alongside large-scale physical experiments, not only focuses on high-fidelity reproduction of structural behavior, which is the foundation of simulation technology development, but also aims to realize high-cycle urban simulations within digital twin environments. At the same time, it is important to build services and infrastructure that can reliably provide high-quality data to those who need it, so that experimental and simulation research can advance together.

At E-Defense, we are committed to advancing research and development in order to generate tangible outcomes through these initiatives. Our goal is to continuously enhance technologies and knowledge that contribute to improving urban resilience.