Tohoku Tsunami-Induced Building Failure Analysis with Implications for U.S. Tsunami and Seismic Design Codes

Abstract

The structural details of numerous damaged buildings in the Tohoku region were documented soon after the 11 March 2011 Tohoku-oki earthquake and tsunami by a reconnaissance team sponsored by the American Society of Civil Engineers. Tsunami flow depths and velocities were determined based on analysis of video records and the observed effects on simple benchmark structures in the flow. Equations for various conditions of fluid loading were then validated through failure analyses completed for several buildings, using finite element modeling and LiDAR scans. These analysis tools were applied full-scale to buildings with clearly identified failure mechanisms to validate methodologies to be included in a new chapter on “Tsunami Loads and Effects” in the ASCE 7-2016 Standard, Minimum Design Loads for Buildings and Other Structures. These findings, together with an analysis of the inherent seismic inelastic capacities of mid-rise buildings, are relevant for establishing the loadings and performance objectives proposed for the new chapter on “Tsunami Loads and Effects” in the ASCE 7 Standard.