Numerical study of reliability index of structure rehabilitated with steel shear wall

Abstract

Uncertainties in seismic demand and structural capacity create conservatism in the acceptance criteria of structural performance levels. This conservatism can be reduced and designs optimised by considering and reducing uncertainties. In seismic rehabilitation, a secondary system added to an existing structure has probabilistic parameters that can lead to changes in existing uncertainties. In this work, a steel moment frame was rehabilitated with a steel shear wall (SSW). Structural uncertainties were investigated by considering probabilistic variables of the force–deformation relationship of the SSW. The results showed that structural uncertainty increased the total uncertainty by 2.0–9.3%. Previous studies that have not considered structural uncertainty due to the force–deformation relationship and may not provide results with appropriate conservatism. As a result, the dispersion of the total uncertainties of a structure rehabilitated with a SSW is close to the dispersion value of a moment frame equipped with a brace, but is more than the dispersion value of the moment frame structure. A parametric study of the reliability index was performed based on probabilistic variables. Based on the results, the structural uncertainty reduced the reliability index by 0.57–1.28%.