Effect of column shortening on the behavior of Tubular structures

Abstract

This paper presents the column shortening effect on the behavior of Tubular, Tube in tube and Bundled tube structure. Frame tube buildings consist of closely spaced column connected by deep spandrel beams placed on the perimeter in plan. A Tube in tube and Bundled tube structure of 50 storeys with storey height of 4 m is considered for the study, RC columnsand spandrel beams are modelled with M70 and M110 concrete mix. Models are developed using ETABS software and theeffect of elastic shortening of the RC column is included in the analysis to study the behavior by calculating member forces. From the analysis, the effects due to elastic shortening in parameters such as axial force, shear force, bending moment andtime period are obtained and compared between the tubular, tube in tube structure and bundled tube structure, there is avariation of about 25%, 20%, 23% and 74% and 23%, 17%, 25% and 57%. 19%, 15%, 31% and 60% respectively, whichresults in the reduction of member size, which ultimately reduces the dead load and the cost of construction.