STRUCTURAL RISK ASSESSMENT AND OPTIMIZED UPGRADES OF AN INDUSTRIAL STRUCTURE 

A structural risk assessment was conducted for a 100 m tall steel oil production structure. The structure was assessed against the governing design load of wind. A pushover analysis was completed using SAP2000 to determine the capacity of the structure against wind. A Reliability-Based analysis was used to assess the safety of the structure given its capacity and the magnitude of the applied wind load. The Reliability Index, a statistical parameter used in defining structural safety, under the existing condition was calculated and compared with code values. The structure was demonstrated to be unsafe. Reliability-Based structural methods were implemented to optimize the upgrades by selectively repairing/replacing members based on the critical failure path. The iterative analysis approach defined the operational safety limitations which relaxed coincidental to the repairs, allowing production to proceed without significant interruption. The innovative optimization approach yielded a 78% reduction in the overall number of members that required upgrades as compared with conventional methods as defined by “Acceptable Solutions” in Part B of the Alberta Building Code.