Assessment and Retrofitting of an Existing Steel Structure subjected to Wind-Induced Failure Analysis

Wind loads are a major threat for old corroded steel structures constructed near the sea where wind speeds can be very high. This paper presents a case study of a wind-induced failure analysis of an existing steel structure and the proposed retrofitting methods. The examined steel structure was constructed in the 1970s in Syros, Greece and is currently operating as an athletic centre. The first part of this study presents the wind-induced failure analysis, from which a domino effect is documented. A corroded bracing that was buckled due to wind load governs the reduction of vertical load carrying of the steel structure and creates an asymmetry under horizontal loading before a number of other steel members failed due to buckling. To understand the structure's performance, failure analysis, as well as time history and incremental dynamic analysis, were performed. The second part of this paper presents the proposed retrofitting methods for improving the vertical load carrying capacity under wind loads. The goal was to improve the load-carrying capacity of the structure so as to comply with current design European codes. In addition, enhancement of the dynamic properties of the strengthened structure was demonstrated using modal analyses. The structural behaviour was determined in a more precise manner via non-linear wind time-history and incremental static analyses. The analytical results explain the development of failures in the existing structure.