Closed-Form Solution To P-δ Effects on the Nonlinear Response of Slender Reinforced Concrete Bridge Columns


Abstract eng:
Inelastic response of columns is governed by geometrical second-order effects in proportion to their slenderness. Experiments on slender reinforced concrete (RC) columns have demonstrated that second-order effects, namely, nonlinear moment gradient and P-δ moments increase the inelastic demands along the column beyond the limits predicted by current expressions for L pr . In this paper, geometrical nonlinear beam theory in conjunction with a bilinear inelastic momentcurvature section response was utilized to determine: (1) the magnitude by which the inelastic response of RC columns is affected due to their slenderness, (2) a slenderness limit for RC bridge columns defined in terms of design variables, and (3) the influence of different structural, geometrical and material parameters on the vulnerability of slender columns to secondorder actions. To investigate the slenderness effects, a parametric study was conducted on all the possible design configurations that are permitted by the latest seismic design guidelines for bridge columns. It was found that the susceptibility of RC bridge columns to second-order effects were mainly dominated by three parameters, namely, the longitudinal steel reinforcement, axial load, and aspect ratios. This study led to the identification of accurate slenderness limits for the noted parameters beyond which the second-order effects on the inelastic response of RC bridge columns are significant and can no longer be ignored. Recommendations are made based on the presented findings to update the current design guidelines for consideration of second-order effects. Finally, simple expressions are proposed to predict the effects of second-order P-δ moments on the length of the plastic region (L pr ).

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Conference Title:
Conference Title:
16th World Conference on Earthquake Engineering
Conference Venue:
Santiago (CL)
Conference Dates:
2017-01-09 / 2017-01-13
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Text je chráněný podle autorského zákona č. 121/2000 Sb.



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 Record created 2017-01-18, last modified 2017-01-18


Original version of the author's contribution as presented on USB, paper 3095.:
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