LATERAL DISPLACEMENT OF HIGH-RISE BUILDINGS DURING CONSTRUCTION USING STAGED CONSTRUCTION ANALYSIS

Abstract

This study investigates the lateral displacement of a 30-story reinforced concrete building (24×24 m) under construction dead load. Wind and earthquake loads are excluded. The aim is to evaluate the effects of the construction sequence and of the shear-wall layout (symmetric and asymmetric). A three-dimensional structural model was developed using linear-elastic material behavior and including P–Δ effects. The results from instantaneous analysis (IA) were compared with those from staged construction analysis (SCA) for both symmetric and asymmetric lateral systems. IA predicts a monotonic increase in lateral displacement with height, reaching 66.8 mm at the top floor. In contrast, SCA gives a maximum of 17.5 mm at the 21st floor. The asymmetric case shows much larger displacement than the symmetric case (17.5 mm versus less than 1 mm). The displacement is largest in the direction of lower overall lateral stiffness. This response is mainly a one-directional sway rather than torsion. The maximum inter-story drift ratio is about 0.45/500, well within the typical serviceability limit (1/400 to 1/500). These findings indicate that both the location and magnitude of peak deformation during construction can differ from those predicted by instantaneous analysis. It can be concluded that staged construction analysis is appropriate for evaluating deformation during construction. This is especially true for high-rise buildings with asymmetric lateral systems, where the maximum displacement may not occur at the top floor.