Reliability of structural wall shear design for tall reinforced-concrete core wall buildings

• Published in: Engineering structures Vol. 252; p. 113492
• Main Authors: Kim, Sunai, Wallace, John W
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.02.2022; Elsevier BV
• Subjects: Acceptance criteria; Concrete; Concrete construction; Demand; Design; Ground motion; Guidelines; Material properties; Nonlinear response history analysis; Performance-based design; Population studies; Reinforced concrete; Reliability; Reliability analysis; Reliability aspects; Reliability engineering; Safety; Shaking; Shear design; Shear strength; Structural reliability; Tall buildings; Tall core wall building; Performance-based design; Reliability; Nonlinear response history analysis; Shear design; Tall core wall building; Reinforced concrete
• ISSN: 0141-0296; 1873-7323
• DOI: 10.1016/j.engstruct.2021.113492

•Literature review was conducted for the shear design of tall RC structural walls.•Reliability studies were conducted for the shear design acceptance criterion.•Recommendations in the current tall building guidelines were reviewed. The developments of shear design acceptance criterion for structural walls in tall reinforced-concrete core wall buildings were reviewed and reliability studies were conducted. Over the past 10 years, the seismic action portion of the shear design acceptance criterion has consistently been in the general format of γFu ≤ ϕFn,e, where γ is the demand factor, Fu is the mean shear demand resulting from a suite of ground motions, Fn,e is the nominal shear strength computed from expected material properties, and ϕ is the uncertainty in Fn,e. Between the governing code, ASCE7-16, and the tall building guidelines, PEER TBI (2010, 2017) and LATBSDC (2011, 2014, 2017, 2020), there has been a lack of consensus in the recommendations for γ and ϕ factors. Thus, reliability studies were conducted on the shear design acceptance criterion, with 20- and 30-story case study buildings designed and analyzed per LATBSDC (2014) guidelines. Using closed-form solutions and Monte Carlo simulations, for the range of f’c considered, the shear design acceptance criterion using γ = 1.5, ϕ = 1.0, and a conservative dispersion in shear demand of ρD = 0.50 resulted in at least 94.2% reliability, conditioned upon MCE hazard level ground shaking, suggesting that the current LATBSDC (2020) recommendations provide adequate safety. For a reduction in safety (e.g., use of γ < 1.5), further reliability studies including a larger population of tall buildings will be needed to calibrate γ and ϕ factors.