Reliability Analysis of Slender Reinforced Concrete Column under Biaxial Loading
Authors: Suleiman A, Uche OAU, And Abdulwahab MT
Limit state equations for slender reinforced concrete column subjected to biaxial bending, considering axial, deflection and bending mode of failure were derived. Their reliability levels were then evaluated as the axial mode of failure is 4.52 (Pf = 1.08E-03), deflection mode of failure is 3.47 (Pf = 1.38E-03) and biaxial bending mode of failure is 4.61 (Pf = 1.84E-03). All basic design variables involved were treated as random variables with their statistical distribution adopted from literature. The results showed that safety index decreases with increase in load and largely depends on their variable parameters. Sensitivity analysis was also carried out on the column section to determine how the design variables behave in respect of their safety indices. The result showed that safety index increased with increase in variables such as characteristic strength of concrete, area of concrete section, characteristic strength of steel reinforcement, area of steel reinforcement, width of concrete section and overall depth of concrete section while it decreased with increase in the applied load. The design becomes critical for all the variables at the applied axial load of 2243 kN and beyond. This is in line with the safety indices range of 3.70 (Pf ?10-6) to 4.70 (Pf ?10-6) recommended by Joint Committee on Structural Safety for structure with large consequences of failure.
Affiliations: Department of Civil Engineering, Kebbi State University of Science and Technology, Kebbi, Nigeria.
Keywords: Reinforced Concrete, Slender Column, Reliability Analysis, Uncertainties, Safety Index
Published date: 2019/06/30