Seismic Response of Structural Walls with Reinforcement and Geometric Discontinuities
The objective of the project was to study the seismic response of structural walls with a vertical stack of openings that terminate in a solid wall in the lower stories in building structures. Abundant field evidence shows that panel zones below the stack of openings are vulnerable to shear distress when subjected to lateral loads. Shear stresses can be increased if there are reinforcement discontinuities in or near the panel zone.
Two walls were tested to study the response of structural walls with a stack of openings subjected to lateral loads (see attachment). One specimen had all longitudinal reinforcement continuous. The second specimen had the longitudinal boundary-element reinforcement flanking the openings anchored in the solid wall region.
Distress caused by shear below the openings shifted the critical section resisting bending moments to the base of the first story. This shift caused an anchorage failure in the wall where the longitudinal reinforcement that flanks the openings was anchored in the solid wall panel.
Project website: http://nees.org/warehouse/project/1050
Faculty Investigator: Santiago Pujol
Graduate Student: Enrique Villalobos