This award will provide supplementary support to enable Dr. Mohsen Sultan of the California Department of Transportation (Caltrans) to conduct collaborative research with Dr. Kazuhiko Kawashima for 12 months at the Public Works Research Institute in Japan. They will conduct research on seismic design methods of highway bridges, comparing the California and Japanese methods. Since the 1989 Loma Prieta earthquake, the importance of accurate prediction of structures' behavior during large magnitude earthquakes has been reemphasized. An expert in bridge design and Project Manager of the Division of Structures, Caltrans, Dr. Sultan investigated the structural damage caused by the 1989 earthquake as a member of the Caltrans Post Earthquake Investigation Team. Dr. Sultan's expertise in the ductility method in seismic design will complement Dr. Kawashima's expertise in a seismic design method of rigid foundations as they compare designs of several bridges. Yielding a much better understanding of the differences between the two systems, the research will help in retrofitting existing bridges, in designing new bridge projects, such as a long span bridge to cross the Carquinez Straight, and in evaluating the seismic safety of existing bridges such as the San Francisco Bay Bridge.