INFLUENCE OF AXIAL SHORTENING OF VERTICAL MEMBER IN THE TALL STRUCTURES

Abstract

Nowadays, there is major demand for commercial and the residential buildings due to population growth in our country, this results in construction of large no of tall structures. Reinforced concrete is the most common material used for the construction of the tall buildings. During the analysis the gravity load, lateral loads due to earthquake, other loads and their load combinations should be considered .Nowadays to avoid the lateral displacement large column sizes are provided which is not economical. Therefore , the core with shear wall are provided. These shear walls will not only resist the lateral loads due to earthquake but it also resist the axial loads acting on the tall structure. This may lead to shortening between two neighboring vertical member. The conventional method is the method of analysis considered for tall buildings. In this method all loads applied in a single step ie post construction stage analysis , but in practice self-weight and part of live load are released on the building gradually as the construction progresses and therefore construction stage analysis using E-TABS software dynamic analysis ie Response spectrum needs to be carried out. In the present work, a parametric study is carried out on Axial shortening of vertical members in tall structure. The parameters considered are varying the columns sizes, increasing storey height and grade of concrete. Comparison of various parameters such as differential shortening using post construction stage analysis and construction stage analysis is studied.