INVESTIGATION OF THE EFFECTS OF P-DELTA ON TUBULAR TALL BUILDINGS

Due to rapid urbanization availability of land for buildings has become scarce, especially in urban landscape and the only way to overcome the same is go for vertical expansion resulting in tall buildings. Tubular tall buildings offer a viable solution for building heights greater than 120 m. However designing tall skyscrapers poses unique structural challenges which have to be overcome. There are several factors to be considered in the design of tall buildings out of which p-delta effect is an important one. Tall tubular buildings are designed not only to satisfy strength requirements but also serviceability considerations in the form of drift and deflections. P-delta effect is expected to cause additional deflections as well as moments. The configuration of the structure like its plan dimensions, height to least lateral plan dimension ratio and lateral stiffness play a significant role accentuating p-delta effect. This paper is an attempt to study systematically the effects of p-delta in tall tubular buildings. In this paper 9 models are analyzed and designed to understand the effect of p-delta. The models considered are of tubular rigid frame structures of total height of 126 m consisting of 42stories each. The models are analyzed for vertical as well as lateral earthquake loads using STAAD-Pro software.