Nonlinear response potential of real versus simulated ground motions for the 11th March 2011 Great East Japan earthquake

This study compares the nonlinear response potential of generic inelastic single-degree-of-freedom systems subjected to three sets of ground motion records for the 2011 Tohoku mainshock. The compared record sets, all for the same sites, are: (i) observed accelerograms at 48 KiK-net strong motion stations; (ii) time-histories simulated from the empirical Green’s function method; and (iii) time-histories simulated using the stochastic finite-fault method (with multiple sub-events). The adopted techniques can capture a realistic source rupture process involving multiple strong motion generation areas in simulations. Statistical analysis of computed peak ductility demands for the three record sets is conducted via cloud and stripe analyses. Results indicate that for the 2011 Tohoku mainshock, different record sets produce similar average trends of the inelastic seismic demand curves. This conclusion is applicable to both cloud and stripe approaches and to structural systems with degrading and pinching hysteresis.