Resources

There are approximately 270 bridges on New Zealand’s state highway network and many more bridges on local roads with steel concrete composite superstructures. From an investigation of as-built records, most of these consist of reinforced concrete decks connected to braced steel I-beams, with welded channels or studs used to provide longitudinal shear connection. Over 70% of these bridges were constructed between 1950 and 1970, of which approximately three quarters were designed by the Ministry of Works. Significant variability currently exists in the assessed live load capacity of composite bridges, even when they are designed to identical design loadings.

This report reviews international experiments for shear connectors and the development of design equations in different national standards. A new equation for channel shear connectors was developed and evaluated through reliability analysis to ensure the target margin of safety was achieved.

An evaluation procedure for composite bending capacity is proposed in this report, incorporating the newly developed design equation of the channel shear connectors and adopting the Eurocode-based solution, which covers a wide range of application. The evaluation procedure is an extension of the existing evaluation steps in the NZ Transport Agency’s Bridge manual (3rd edition).

Keywords: angles, composite bridges, channels, historic, material properties, NZ Transport Agency, NZ Transport Agency Bridge manual 3rd edition, shear connector, shear studs, standards.