Earthquake response of slender planar concrete walls with modern detailing

Reinforced concrete structural walls are used commonly as the primary lateral-load resisting system in buildings. The research presented here represents the results of the first phase of a multi-year research effort aimed at developing tools to enable performance-based earthquake engineering (PBEE) of structural walls. The first phase of the research effort focused on the seismic behavior and analysis of slender planar walls and included laboratory testing of four planar wall sub-assemblages. The walls simulated the bottom three stories of a 10-story prototype building; loading apparatus available at the University of Illinois, Network for Earthquake Engineering Simulation laboratory were used to simulate the load demands, permitting maximum test-specimen scale and realistic demand patterns. The walls were detailed to modern code requirements and standard practice and included heavily reinforced boundary elements. The test matrix studied the effects of reinforcement layout, shear demand, and lap splices at the base of the wall. All of the walls exhibited damage in the compression region, even at relatively low drifts. The splice affected the location of the damage. Walls without splices sustained damage at the base of the wall; walls with splices sustained damage at both the top of the splice and the base of the wall, with the critical region depending on the shear demand. Shear demand also affected response; a moderate increase in shear demand resulted in the failure mechanism changing from bar fracture to flexure–compression failure of the boundary elements.

► Large-scale tests of slender reinforced concrete walls.
► Studied impact of shear and reinforcement layout, including lap splices at base.
► Walls sustained flexural (low shear) or flexural–compression (higher shear) damage.
► Drift capacity ranged from 1.2% to 1.9% drift. Increased shear reduced drift capacity.
► Lap splices impacted location of damage but did not reduce drift capacity.