STRUCTURAL FIRE RESPONSE OF TALL BUILDINGS WITH INCLINED AND BI-LINEARPERIMETER COLUMNS

摘要

This paper considers the effect of perimeter column angle-of-inclination on the structural response of tall buildings subject to fire.The purpose of the study is to aiddesigners when doing structural fire assessments of tall buildings.The consequences of columnangle-of-inclination and its interaction with the floor-plate are examined.It has been found that inclined and vertical columns have a similar structural fire response.However, bi-linear columns that have two angles-of-inclination have been found to behave differently compared to linear columns when exposed to fire.Bi-linear columns induce increased in-plane axial forces on the floor slab during both ambient and fire conditions.Thisaffects the behaviour of the floor under fire conditions.A parametric study was carried out for a range of bi-linear columns by varying the angle-of-inclination and applied axial load.It was found that bi-linear outwards columns are more vulnerable to the effects of fire than bi-linear inwards columns due to the P-delta effect on the adjoining beams.This may result in bi-linear columns not achieving their specified fire resistance period unless additional mitigation measures are provided and/or an analysis is conducted to verify the performance under fire conditions.