Effects of Torsion Lateral Stability of Building Structure

Abstract

This paper surveys the effects of torsion on the global lateral stability of a shear wall building with typical plan and elevation layouts. In order to achieve the goal of study, a parametric investigation procedure is undertaken, on a series of sample structures with a condition which can cause torsion and their lateral stability under earthquake and gravity loading is investigated and discussed. To study the effects of torsion on the lateral stability of building structures, three asymmetric models are constructed by moving the shear-wall couple in the centric model from grid lines “-X1_X1” to grid lines “X1_ X2” in one model, and to grid lines “X2_X3” and grid lines “X3_X4” in another models. In addition the effects of axial loading and increasing storey number on the lateral stability of building structures are parallely studied on one of the series models. To study the influence of storey number, three different stories are constructed on the same series model keeping their inter storey height constant. Load-displacement diagrams are constructed for the above three conditions and are shown in Figure 6-1_Figure 6-10. From the Load-displacement diagrams, global lateral stability “D” is computed. Reduction in global lateral stability due to the induced asymmetry proved to be (89%, 97% and 98%) respectively. Furthermore it is shown that the effect of axial loading is considerable in both the centric and eccentric wall configurations. And the lateral stability of a structure on the same configuration decreases while increasing storey number. Thus depending on the analysis results conclusions and recommendations are made and some further studies are forecasted