Sequential time-history analysis of building structures under earthquake and tsunami loads

To develop the sophisticated evaluation method of tsunami-resistant performance for building structures, sequential non-linear time-history response analysis under earthquake and following tsunami loads was performed and the fundamental behavior of building structures was discussed. Then a time-history model for vertical profile of tsunami wave was developed based on the results of fluid analysis using smoothed-particle hydro-dynamics (SPH) method. Applying the proposed time-history model for vertical profile of tsunami wave as the input load after an earthquake load in the sequential non-linear time-history response analysis, the following results were revealed. (1) Froude number affects the vertical distribution of the maximum tsunami pressure to building structure. And Froude number affects also the vertical distribution of inter-story drift ratio of building structure. The proposed time-history model for vertical profile of tsunami wave shows the results of an approximate vertical distribution of inter-story drift ratio of building structure obtained from the results of SPH fluid analysis. (2) According to the sequential non-linear time-history response analysis under earthquake load and following tsunami load with the proposed time-history model for vertical profile of tsunami pressure, it is revealed that structural damage by earthquake affects the maximum displacement of building structure by tsunami. It is important to detect the deterioration of fundamental period caused by the seismic damage for detailed tsunami-resistant performance evaluation.