Experimental investigation of end-plate splices with multiple bolt rows of large girders

Abstract

An experimental investigation of four extended end-plate welded girder splices with M20-grade 10.9 bolts, multiple bolt rows, and multiple bolts per row was conducted. Two splices of beam (1.5 m depth with 11 bolt rows and 2 or 6 bolts per row, and 2 splices 1.0 m high with 6 bolt rows and 4 bolts per row were investigated. In both these cases, the bolts were close to the tension flanges. All of these joints can be considered as rigid and partial-strength joints. Experimental research on such end-plate connections has not been previously conducted; therefore, the understanding of the overall structural behaviour of these types of connections is currently insufficient. The main objective of this study was to investigate the bolt-force distribution at the ultimate state of the bolt tension resistance in the connections. The longitudinal strains of bolts in three investigated splices were measured in all rows until the bolts ruptured. The test results for the splice with two bolts per row indicated that forces in bolts adjacent to the web (and distributed along the height of the beam web) were significantly smaller than the T-stub resistance computed according to EN 1993-1-8. Further, the bending-moment resistance of such a connection obtained using the component method overestimated the actual splice resistance. It is concluded that Eurocode procedures do not satisfy safety requirements in the case of multi-bolt row connections.