Lateral stiffness characteristics of tall reinforced concrete buildings under service loads

This paper presents an analytical method for quantitatively predicting the effects of cracking on the lateral deflection and stiffness characteristics of tall reinforced concrete buildings under service loads. The effects of cracking in tall reinforced concrete buildings can be considered using an element stiffness reduction model. This model determines the probability of cracking occurrence by dividing the area of the moment diagram, S-cr, where the working moment exceeds the cracking moment by the total area of the moment diagram, S. A practical cracking analysis method can be established by integrating the proposed stiffness reduction model with an iterative algorithm and commercial linear finite element analysis package. The proposed method has been validated by good agreement of results between the numerical computation and experimental testing of large-scale rigid-frame and wall-frame structural sub-assemblages. The effectiveness of the numerical analysis method is also illustrated through a practical 40-storey reinforced concrete building example. The cracking effects on the lateral deflection and stiffness characteristics of this building were analysed both explicitly and quantitatively. Copyright (C) 2000 John Wiley & Sons, Ltd.