Title:
Reliability Analysis for Eccentrically Loaded Columns
Author(s):
Maria M. Szerszen, Aleksander Szwed, and Andrzej S. Nowak
Publication:
Structural Journal
Volume:
102
Issue:
5
Appears on pages(s):
676-688
Keywords:
columns; eccentricity; reinforced concrete
DOI:
10.14359/14663
Date:
9/1/2005
Abstract:
This paper presents reliability analysis for eccentrically loaded reinforced concrete (RC) columns, based on new improved statistical data for the constituent materials. The strength limit state functions were developed for reinforced rectangular columns, depending on the cross section size, reinforcement ratio, and load eccentricity. For a known eccentricity condition, closed-form solutions for the corresponding force-moment strength in the interaction diagram were developed. The calculations for cast-in-place and plant-cast columns made of normal concrete and high-strength concrete were performed. The statistical parameters of resistance were calculated using Monte Carlo simulations. Sensitivity analyses were performed to determine the design parameters that have the highest influence on the reliability index. Many two- and three-dimensional plots were generated to show the reliability index versus concrete strength, reinforcement ratio, load combination, normalized eccentricity, and tensile strain in steel. The required strength reduction factor is calculated for a predetermined target reliability index to achieve accepted level of structural safety. The strength reduction factor for RC columns is proposed in a convenient form for design procedures, depending on the tensile strain in steel and the reinforcement ratio.