Title: A Predicting Method for Long-Term Behavior of Reinforced Concrete Moment Frames
Author(s): Mohammad Jalilzadeh Afshari and Ali Kheyroddin
Publication: Structural Journal
Appears on pages(s): 195-211
Keywords: conventional one-step analysis; creep; differential column shortening; long-term vertical displacement; nonlinear staged analysis; shrinkage; time variation of modulus of elasticity
The accumulative shortening of columns in conventional structural analyses and the resulting destructive effects are among the most important factors occurring due to neglection of compliance in the design of high-rise reinforced concrete structures and the practical stages of implementation. In this study, by performing modeling and nonlinear staged analysis on structures with different geometrical characteristics and environmental conditions, simple semi-empirical equations have been proposed to estimate vertical displacement of columns caused by creep, shrinkage, and time variations of the concrete modulus of elasticity in such a way that the equations are independent of the cross sections of the structural elements and common parameters in the estimation of the axial strains. The results of verification of the proposed equations were indicative of the highly desirable consistency of the values estimated by the proposed equations and the actual values obtained from nonlinear staged analysis, with a mean error of less than 4.33%, in structures of up to 30 stories considered as the scope of investigation of the present study.