Torsional Improvements in a Multistoried Building with Plan Irregularities

Abstract

Irregular buildings consist of large number of modern urban structures. Though some buildings look symmetrical in plan might have irregular distribution of mass, strength and stiffness along the plan and height of the buildings. In common sense, a building with a regular geometry is supposed to be regular building. While the building is designed to be used for different functions along the building area and along the building plan the presence of opening, staircase positioning and positioning of the shear/core wall for different purpose like lift and HVAC (Heating, Ventilation and Air Conditioning) leads to the irregularity in the plan. Ultimately, torsion irregularity occurs, which if remains not taken care properly may create substantial damage of the building structures. The purpose of this study is to determine the conditions for excessive torsional irregularity and solve them with the proper positioning of the shear wall to counter the torsional behavior of the building. A linear response analysis was conducted and the studied structures were both six- storey buildings. First building has opening left for different purpose like lift and HVAC systems. While the second building has shear wall for lift at the edge of the building. Though both buildings seem fine with their geometrical orientation after the analysis torsional irregularity was evident. The proper placement of the shear wall has been used to stiffen the building to counter for the torsional modal and make to regular in terms of the mass and stiffness distribution.