Static and Dynamic Behavior of Coupled Shear Wall

Abstract

The reinforced concrete wall primarily resists the lateral load genrated from wind and earthquake. Due to concentration of flexural stresses at the base of solid wall, it exhibits brittle failure like concrete crushing in boundary element and sliding shear at construction joints. In the coupled shear wall (CSW), the sructural walls are connected through the coupling beams. The inherent behavior of CSW reduces the moment in the walls due to the coupling action. In plastic stage, the hinges are formed at the end of coupling beam and then at base of the walls, which causes the dissipation of energy and redistribution of forces through out the structure. The coupling beams also save the structural walls from the excessive damage. Therefore the CSW is not only used for the newly constructed structure but also for the seismic rehabilitation of the existing structure. In the present work seismic behavior of multistoried CSW is discussed with parametric study. The parameters considered in the study are: number of story, length of wall, depth and span of coupling beam. The response of CSW is observed in terms of axial forces, shear and moments in walls and the coupling beams at various floors. An important index to quantify the efficiency of the CSW is the degree of coupling (DC). In this study DC is also evaluated for the different parameters. Time period of CSW is observed to compare the time period formula suggested by Indian Code IS 1893 (Part 1) : 2002. It is found that with suitable dimensions the DC can be kept constant through out building and strong column and weak beam concept can be simulated. It is also found that the time period formulae given in code should include dimensions of CSW for better estimation of seismic forces.