Effective Stiffness of Reinforced Concrete Sections

Estimate the elastic stiffness ratio from digitized design curves using linear interpolation.

Section Parameters

Digitized range: 0.05 to 0.35; input step: 0.01.
Digitized range: 0.01 to 0.04.
Section type
Elastic stiffness ratio
0.49
Ie/Ig

Digitized Effective Stiffness Curves

a) Circular Sections

b) Rectangular Sections

The plotted values were visually digitized from Seismic Design and Retrofit of Bridges by Priestley, Seible and Calvi, John Wiley & Sons 1996. Interpolation is linear between axial-load data points and between adjacent reinforcement-ratio curves. Inputs outside the available range are not extrapolated.