Effect of Outriggers Location on Performance of RC Building Subjected to Loss of a Column

Abstract

Progressive collapse denotes a failure of substantial part of the structure, causing greater damage to the structure than the initial impact, which has been initiated by failure of a relatively small part of the structure such as failure of any vertical load carrying elements (typically columns). Failure of large part of any structure will result into substantial loss of human lives and natural resources. Therefore, it is important to prevent progressive collapse, which is also known as disproportionate collapse. In the current study, progressive collapse potential of 50-storey RC building with outrigger structural system is evaluated. Outriggers are basically rigid horizontal structural members connected between external columns and central core. Effectiveness of different locations of two outriggers provided through the height of building on progressive collapse resistance is studied under two different column removal scenarios. Non-linear static analysis is performed for removal of corner column and side column, separately, from bottom storey, by following US general service administration (GSA) guidelines. Modelling, analysis and design of building is carried out using MIDAS Gen software. From the analysis results, it is observed that building with outriggers provided at top and at mid-height locations gives higher resistance during column removal condition.

Keywords: Progressive collapse, outrigger structural system, non-linear static analysis, high-rise building, column removal scenario