Numerical Analysis of the Load-carrying Capacity of Built-up Columns with Damaged or Missing Lacing Bars

Built-up columns with lacing bars are commonly used in old bridges. Typically, these columns consist of shaped steel members connected by riveted lacing bars. This design held the advantage of reducing steel usage, thereby lowering costs. However, these techniques have become outdated. Nevertheless, structures constructed using these methods persist today. Over time, some of these columns have experienced component loss because of ageing, damage, or corrosion. This study uses finite element analysis to determine the load-carrying capacity of built-up columns with lacing bars subjected to compressive forces. The results indicate that the loss of some lacing bars results in a 2% reduction in load-carrying capacity, while the loss of both lacing bars and rivets leads to a 5% reduction. Though the reduction may appear marginal, the presence or absence of lacing bars and rivets becomes a significant consideration in estimating the remaining load-carrying capacity. The results of this study have implications with respect to the ongoing use and maintenance of built-up columns with missing components, which has emerged as a critical concern.