Effect of wind loading pattern on shear lag phenomenon in framed-Tube Building

Abstract

High-rise tubular buildings experience the shear lag phenomenon due to wind load. This phenomenon results in tension in upper storey columns that may adversely affect building stability. Shear lag varies with many factors such as building layout, outer peripheral columns spacing, and load applied to the building. Therefore, it is essential to accurately analyze the shear lag phenomenon by considering these factors, especially, with due emphasize on the pattern of the applied wind loading. This paper attempts to study the effect of wind loading pattern on the shear lag phenomenon. Six load cases are taken from American and Canadian codes to analyze the wind load effects on a 40-storeyed tubular building. The results indicate that axial force distribution changes significantly with change in the loading patterns of the building. A difference in axial force distribution is observed between torsional and non-torsional load cases. Axial force in columns in the case of uniform loading is more significant as compared to partial loading cases. Due to loading on half of the face, axial force distribution becomes unsymmetrical, and a minimum axial force in corner columns is observed. Also, notable differences can be seen in the axial force distribution of load cases having both direction loadings compared to single direction loadings. Axial force distributions in cases of both face loading are unsymmetrical for the central column.

Keywords

• codal provisions
• framed tube
• shear lag phenomenon
• torsional wind load
• wind loading