Reliability-Based Design Methodology for Reinforced Concrete Structural Walls with Special Boundary Elements

Theunderlying premise of the ASCE 7-10 and ACI 318-14 provisions is that special structural walls satisfying the provisions of ACI 318-14, Sections 18.10.6.2 through 18.10.6.4, possess adequatedeformation capacity to exceed the expected deformation demand determined using ASCE 7-10 analysis procedures. However, observations from recent laboratory tests and strong earthquakes,where significant damage occurred at wall boundaries due to concrete crushing, reinforcing bar buckling, and lateralinstability, have raised concerns that current design provisions areinadequate. Recent studies have identified that deformation capacity of code-compliant walls is primarily a function of wall cross section geometry, neutral axis depth, shear stress demands,and the configuration of boundary transverse reinforcement, and that, in some cases, the provisions of ACI 318-14 may not result in buildings that meet the stated performance objectives. To address this issue, this study proposes a new reliability-based design methodology for structural walls where a drift demand-to-capacity ratio(DDCR) check is performed to provide a low probability that roof drift demands exceed roof drift capacity at strength loss for a specified hazard level. Keywords: design earthquake; design methodology; drift capacity; drift demand; maximum considered earthquake (MCE)-level shaking; special structural walls; strength loss; wall shear stress.