Investigation of Seismic Failure Modes in Flexural Concrete Walls Using Finite Element Analysis

Thesis (Master's)--University of Washington, 2015Reinforced concrete structural walls are a common seismic lateral force resisting system in concrete buildings. They possess high strength and stiffness, which are desirable in resisting low-to-moderate seismic demands. When subjected to larger seismic demands, walls are assumed to develop a flexural response mechanism controlled by tensile failure of the longitudinal reinforcement. However, in recent earthquakes (2010 Chile, 2011 New Zealand) compression failures have been observed in the boundary elements at the ends of the wall, in the interior web region of the wall, or both. These failure modes have been observed in experimental tests as well. In lab settings, the size of the wall specimen and the magnitude of the applied loads (vertical and lateral loads) are limited by the capacity of the laboratory equipment. This study utilized nonlinear high-resolution finite element modeling to enable investigation of the influence of a wide range of design parameters on the behavior of planar walls, including failure mechanisms. The finite element model was developed and calibrated using data from multiple laboratory tests of walls. The calibrated model was used to conduct an extensive parameter study. The results of this study were used to develop new shear stress limits and boundary element length requirements to prevent walls from developing non-ductile failure modes