Improving Total Moment Concept Equations for RC Coupled Shear Walls by Considering Coupling Beams Axial Load

Shear walls are widely used in steel and reinforced concrete buildings and have great importance among structural parts in medium and tall buildings as lateral loads are endured by shear walls. Coupled shear walls are being widely used in recent decades due to architectural and structural necessities. Most studies performed in this area, are addressing load transfer mechanisms, equilibrium equations of wall parts, fracture mechanisms, behavior of coupling beams and also system behavior against cyclic loads. However, effect of axial load in coupling beams has been neglected in these researches. Although many researchers considered this parameter as a negligible term in their works, a simple fact that if there is no axial load in coupling beams, there is no shear loads in the walls, proves inaccuracy of this assumption. The aim of this research is to use equilibrium equations and load transfer mechanisms for rearranging Total Moment Concept (TMC) equations and investigating coupled shear walls response against lateral loads. After improving TMC equations, a set of 3D finite element models are built to verify the results of this equations and compare the new equations to the original TMC equations. Afterwards, the required parameters for calculating TMC and Improved Total Moment Concept (ITMC) are extracted from these 3D models. It is shown that the improved equations are representing coupled shear walls behavior with more accuracy compared to the previous TMC equations. Finally, after comparing these two sets of results, some suggestions are given to improve the design process of coupled shear walls.