Effect of Stairs on Modeling Building Structures Using Nonlinear ETABS

Abstract

In this modern era, engineers are greatly helped with various software, including ETABS software. Structural design, especially buildings carried out with software before the 1980s, either in the seismic region or in the non-seismic, do not consider the existence of stairs because stairs offer greater strength and stiffness and significantly affect the distribution of seismic forces. In this paper, the structure of a 6-story building with and without stairs is modeled and analyzed using ETABS Nonlinear v.9.7.4 software. This paper aims to determine the effect of stairs, in this case, the structure's natural vibration period. Furthermore, the results of the analysis of the building structure without and with stairs using ETABS Nonlinear v.9.7.4 software have been obtained. The analysis results show that the stairs are also modeled in designing the building structure with software. So, the value of the natural vibration period of the structure becomes smaller, with a difference for mode 1 of 11% and mode 2 of 12%.