Nonlinear pushover analyses are widely used today for the seismic analysis of existing structures. This paper aims to investigate the effects of the multidirectional seismic load and the combination rules in the pushover analysis of reinforced concrete structures. In order to consider concurrent seismic effects on 3D models, current seismic codes indicate that elements and components shall be verified considering the seismic demand derived from the same combination rules used in linear dynamic analyses (SRSS or 30% rule). In this study, the above code provision is applied to the pushover analyses performed on several irregular reinforced concrete structures and the results are compared upon application of the lateral loads in different directions. The seismic demand in terms of shear demand and inter-story drift are calculated with the N2 method applying the seismic force both along the conventional structural directions x and y and along incident angles θi varying between 0° and 360° with steps of 22.5°. In order to verify the validity of the multidirectional lateral load application and the code-conforming combination rules, the structural demands obtained from the different pushover analyses are compared with those computed by Non-Linear Time History Analyses (NLTHA) performed by using suites of twenty pairs of both real and generated ground motion records.
Multidirectional Lateral Loads and Combination Rules in Pushover Analysis
Cantagallo, C;Spacone, E;Camata, G
2022-01-01
Abstract
Nonlinear pushover analyses are widely used today for the seismic analysis of existing structures. This paper aims to investigate the effects of the multidirectional seismic load and the combination rules in the pushover analysis of reinforced concrete structures. In order to consider concurrent seismic effects on 3D models, current seismic codes indicate that elements and components shall be verified considering the seismic demand derived from the same combination rules used in linear dynamic analyses (SRSS or 30% rule). In this study, the above code provision is applied to the pushover analyses performed on several irregular reinforced concrete structures and the results are compared upon application of the lateral loads in different directions. The seismic demand in terms of shear demand and inter-story drift are calculated with the N2 method applying the seismic force both along the conventional structural directions x and y and along incident angles θi varying between 0° and 360° with steps of 22.5°. In order to verify the validity of the multidirectional lateral load application and the code-conforming combination rules, the structural demands obtained from the different pushover analyses are compared with those computed by Non-Linear Time History Analyses (NLTHA) performed by using suites of twenty pairs of both real and generated ground motion records.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
