In Japan, and other seismically active countries, the importance of soil-structure interaction phenomenon has been recognized for many years. Various researchers and organizations have actively carried out both theoretical and experimental researches on soil-structure interaction (SSI), and developed analytical tools to be used in structural design.

With the experience of the 1995 Kobe earthquake, preparedness for future destructive earthquakes is recognized as the main goal. To this end, large-scale earthquake observation networks and large scale testing facilities are being planned.

This year, the Building Standard Law in Japan has been revised. For the first time, it includes the earthquake load considering the SSI effect. We recognize that this is just a starting point.

To incorporate SSI effects into the design procedures, the following general issues have yet to be solved.

To clearly determine the SSI phenomenon during vibration caused by earthquakes and wind.
To carry out research on understanding the inelastic and/or nonlinear behaviour caused by SSI, particularly during strong shaking.
To clarify the external loads which are a combination of inertial force and ground displacements in case of pile foundations.

It is the aim of this workshop to discuss these issues. The Japanese Organizing Committee cordially invites leading researchers from U.S. and Japan to share their researches and experiences, to identify the issues to be solved urgently and to facilitate suggestions for future research direction in the field.

During the workshop, the following essential topics will be covered:

Current methods of practice of SSI in US and Japan
1. Geotechnical point of view
2. Structural point of view
Code provisions and limitations.
Observed data.
Observational arrays and testing facilities - Current, future and needs.
Recent research results and how to implement them into practice.
Needed additional research.
Needed additional observational arrays and testing facilities.