Development of Post-to-Deck Connections for Use in a MASH TL-4 Steel-Tube Bridge Rail

A new post-to-deck connection was designed for mounting an upcoming Manual for Assessing Safety Hardware (MASH) Test Level 4 steel-tube bridge rail to the side of the bridge deck to limit impact load transferred to the deck and to minimize the propensity for deck damage during impacts. With preference for the bridge rail system to be compatible for use on all deck configurations, the Illinois and Ohio Departments of Transportation desired the new system to attach to bridge decks comprised of concrete slabs or precasted prestressed, concrete box-beam girders. A new post-to-deck connection for a new MASH 2016 TL-4 steel-tube bridge rail was developed and tested. The connection featured a W6x15 steel post to be side-mounted to the deck. The post-to-deck connection was designed to fully develop the plastic bending capacity of the W6x15 post without causing deck damage. Post anchorage hardware was also designed to sustain impact loads transferred to the deck while preventing deck damage. Four post-to-deck connection concepts were developed and optimized through dynamic component testing. Only lateral impacts were conducted on the design concepts, side-mounted to a concrete box-beam girder. For the dynamic component testing, post-to-deck connection concepts varied on the type of welded post assembly connecting to longitudinal tube spacers, which in turn mounted to various post anchorages casted within the concrete box-beam girder. The resulting damage from each test varied from plastic deformation of the post between two plate attachments on the post assembly or post bending above one singular plate attachment due to the development of a plastic hinge near the surface of the deck. The post-to-deck connection featuring a singular plate attachment with longitudinal tube spacers was recommended for use based on the post bending near the surface of the deck, as intended. Advisor: Jennifer D. Schmid