A Study on Load Combination Method Considering the Correlation among Dynamic Loads : 1st Report, Load Combination for seismic Response Analysis of Liquid Storage Tank

Abstract

This report deals with fundamental study concerning various kinds of dynamic load combination problems. Up to the present, the square root of sum of squares (SRSS) law has been widely utilized for various load combination problems. However, considerable error is produced during the combination based upon SRSS law, particularly when correlation among loads to be combined becomes significant. In this study, a load combination technique introducing an evaluation of the correlation is proposed. It is applied to a seismic response analysis problem of a large-scale liquid storage tank inducing sloshing effect in order to evaluate the base shear coefficient and the overturning moment. It has been made clear that the proposed method is reasonable by comparing with the SRSS-based law and the absolute value summation. And, the merit becomes dominant when combination is carried out not based upon ordinary absolute acceleration response spectrum but based upon relative acceleration response spectrum as input load.