Assessment of Design Long-period Earthquake Motions for High-rise and Base-isolated Buildings

It was presented in the previous joint panel in 2011 that we have made a proposal on method for evaluating the long-period earthquake motion time history with periods from 0.1 to 10 second using designated earthquake magnitude, shortest distance to the source area and location of hypocenter in view of establishing the generation scheme for design long-period motions for super high-rise buildings and applied it for the simulation of large subduction-zone earthquakes. The 2011 Off the Pacific coast of Tohoku earthquake has provided us with an opportunity to examine the method by comparing recorded motions with simulated ones. We had made revisions to this proposed method. We also made simulations for the Tohoku earthquake with the revised method. We have obtained better fit of the formula to the recorded motions. In addition, long-period ground motions were simulated for a three-events-connected source model expected to occur in the Nankai trough region.