Alternative Design of Column Web Doubler Plates in Steel Pipe Rack Modules

Heavy industrial structures are commonly constructed using structural steel. Pipe-supporting structures which are also referred to as pipe racks are an example of these types of structures. They carry the anticipated loads using a gravity load-resisting system combined with concentrically braced frames and moment-resisting frames. Due to similar loading conditions along the network, pipe rack structures are broken into several repetitive volumetric modules that can be prefabricated off-site. To resist all the loads that these structures anticipate, continuity plates and complex welding applications are used in the design of the connections of these modules. The connections to be designed are beam-to-column moment connections. To transfer flexural bending from beams to the column in these types of connections, web doubler plates are often required when the thickness of the column web is not sufficient to carry the moments. Groove welds are typically used to attach the web doubler plates to the column radius in the connection region. The detail and type of weld can vary from fabricator to fabricator because of the challenges associated with the implementation of such welds in the K-region of the column section. The industry partner of this study (WF Steel & Crane) uses a detail that can be treated as a PJP weld due to the welding position and the inherent difficulty with surface preparation and inspection. The target is the development of an alternative design for steel moment connections used in modular pipe racks by means of laboratory testing and advanced numerical simulations to improve the fabrication process of such connections.