Time-Dependent Deflection of Slab Affected by Construction Load

Abstract

Long-term deflection is a critical issue in the design and construction of long-span flat-plate slabs that have become popular for tall buildings. In the present study, a numerical analysis method was developed to predict the long-term deflection of flat plates. In the proposed method, variations of construction load, moment redistribution due to slab cracking, and long-term effect of creep and shrinkage were addressed. The proposed method was applied to slabs in two actual multi-story buildings under construction. The predicted long-term deflections were compared with the on-site measurements. The results showed that the immediate deflection due to the construction load significantly increased the long-term deflection, and the predictions agree with the measurements.