Seismic force modification factors for partitions in low-rise reinforced concrete buildings

Abstract

Present codes of practice do not consider the effect of arrangement of partitions in the plan of structure on the seismic demands of these non-structural components. In this paper, a modification factor has been proposed to modify provisions for those seismic demands. Seventy two regular low-rise reinforced concrete moment frames, supporting some partitions, exposed to seven appropriate ground motions. The nonlinear seismic response history analysis considering out-of-plane behavior of partitions has been conducted using the OpenSees platform. The average values of peak responses from those earthquakes were obtained. The forces generated using the analytical method, which some of them verified with existing study results, were compared with the values from the code and a factor denoted as seismic force modification factor, W, was proposed. A parametric study has been carried out to study the effect of dominent parameters such as the arrangement of partitions, partition to structure height ratio, and length to height ratio of partitions on the W values. For the majority of the models, the W values are larger for partitions located further with respect to the center of floor. Moreover the modification factor could be as large as 1.85 for the partitions located in the middle floors.