9614120 Yeh Earthquakes which occur on ocean floors set in motion the entire water column above the region of tectonic plate motion, generating a tsunami (seismic sea wave). Such waves, when approaching shore, can reach a height of more than 10 meters and can cause extensive flooding, property damage, and the loss of human lives. This action is to support a comprehensive research program to understand local tsunami effects on man-made and natural structures. Particular emphasis is placed on understanding tsunami-structure interactions that can lead to effective damage mitigation measures. The program includes computational, experimental, and mitigation components conducted by research teams at Southern Methodist University, the University of Washington, and Urban Regional Research, respectively. The new robust method for the numerical simulation of waves and their interaction with structures developed at Southern Methodist University is used to simulate transient tsunami flows over and around coastal structures. The highly sensitive capacitance-type wave gage, and the optical water-surface profiler developed at the University of Washington is used to conduct tsunami experiments in a specialized three- dimensional wave basin. The direct field experience of Urban Regional Research in the assessment of tsunami damage and the identification of vulnerability patterns guides the computational and experimental research. The collaborative effort enables the development of tsunami mitigation measures. The set of laboratory experiments and numerical simulations are sufficiently simple that the basic physics of tsunami actions on structures can be explored. At the same time, the experimental set-up and choice of problems is realistic, so that the results provide the means for the design and modification of shoreline structures. Throughout the research, full advantage is taken of the multi-disciplinary nature of the research team. The analyses of actual tsunami even ts guides the numerical and experimental efforts by focusing the proposed investigations on the most practical and relevant problems for tsunami hazard reduction. The intended, primary impact of the proposed research is the mitigation of the devastating consequences of tsunami events, including loss of human life, destruction of property, damage to the environment, economic disruption, and social dislocation. ***
