Effective Stiffness of Rectangular Confined Concrete Columns with Continuous Compound Spiral Hoop

Abstract:

Existing models appropriate for design applications tend to overestimate the measured effective stiffness and are unacceptably inaccurate, because they generally neglect the influence of anchorage slip on the effective stiffness of the column. A three-component model that explicitly accounts for deformations due to flexure, anchorage-slip, and shear is shown to provide a more accurate estimate of the measured effective stiffness for the database columns. This model is simplified by neglecting small terms and approximating the results of moment-curvature analysis to obtain an accurate and rational effective stiffness model appropriate for design applications. Comparison the measured effective stiffness of reinforced concrete columns from the PEER Structural Performance Database with stiffness calculated following the FEMA 356. The FEMA 356 procedure substantially overestimates the stiffness of columns with low axial loads, in which there can be significant bar slip in the beam-column joints or footings. This model provides practical recommendations for improving estimates of effective stiffness.

• Periodical: Applied Mechanics and Materials (Volumes 166-169)
• Pages: 674-679
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.166-169.674
• Online since: May 2012
• Authors: Wei Li, Lei Jiang, Lin Zhu Sun
• Keywords: Bar Slip, Continuous Compound Spiral Hoop, Effective Stiffness, Flexure, Rectangular Concrete Columns, Shear

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