Contribution of coupling elements to the seismic demand of walls in reinforced concrete buildings

Architectural configurations of reinforced concrete (RC) wall buildings force the connection of structural walls with beams, slabs and adjacent walls to distribute habitational spaces, generating interaction between those structural elements that results in a coupled structural system. Studies on resisting planes of RC buildings damaged during 2010 Chile earthquake suggest that the behavior of structural walls was highly influenced by the interaction of the resisting plane with the rest of the structure. Furthermore, researchers have identified 7the high levels of axial load as one of the principal causes of the observed wall damage on these buildings, and that a significant amount of this load comes from the seismic demands. However, there is uncertainty about how different coupling elements contribute to the seismic demands in RC walls. In this work, the seismic demands of axial load, shear and moment of RC walls are estimated from three buildings damaged during the 2010 earthquake using detailed finite element models that consider their three-dimensional layout. the contribution of coupling elements to the seismic demands of the studied RC walls is determined. Additionally, the effects of the assumed stiffness of structural elements over the seismic demands is evaluated. The results show that slabs have the largest contribution to the seismic axial load in walls, contributing with more that 90%, followed by adjacent walls and connecting beams. Furthermore, the obtained moment and shear diagrams of the studied walls are significantly different than those of cantilever walls, and it was found that the assumed stiffness of structural elements exerts an important effect on the prediction of the seismic demands in RC walls.