Title: Strength Reduction Factor for Circular Reinforced Concrete Columns

Author(s): Tomasz A. Lutomirski, Andrzej S. Nowak, and Marta Lutomirska

Publication: Structural Journal

Volume: 119

Issue: 4

Appears on pages(s): 303-310

Keywords: calibration; circular columns; reinforced concrete; reliability model; resistance factor; strength reduction factor

DOI: 10.14359/51734653

Date: 7/1/2022

Abstract:
A reliability-based calibration for new strength reduction factors for eccentrically loaded short circular reinforced concrete columns is presented. The statistical parameters of resistance used in the calibration procedure are based on a developed procedure for the determination of the capacity of columns and Monte Carlo simulations for representative design cases. The reliability indexes were calculated for predetermined resistance factors considering various dead load to live load ratios and all possible failure modes represented by the steel strain. Then, they were compared to the target reliability index, which was assumed as βT = 4.0. The determined strength reduction factors correspond to load and load-combination factors specified by ASCE 7-16 and adopted by ACI 318-19. They are compatible with the existing provisions for resistance factors for rectangular columns.