The Confederation Bridge spans the Northumberland Strait and connects Prince Edward Island to mainland Canada. Baird completed a comprehensive scour investigation for the project, including the assessment of scour potential, design of scour protection for selected piers and the design and implementation of a scour monitoring program.
The $840M Confederation Bridge, constructed in 1994-97, is the world’s longest bridge over ice-covered water. Extreme ice loads in combination with seabed scour was a key failure mechanism to be addressed in the design. Baird completed a multi-faceted study to assess scour potential, including numerical modeling to define metocean conditions, physical modelling of wave-current interaction with the bridge piers, review/analyses of borehole records at 65 piers, and development of a new methodology to estimate scour potential in “complex” materials (cohesive tills and weak, fractured bedrock). The physical model was also used to design scour protection for piers where scour was predicted to occur during the 100 year event.
Given significant variability in the subsurface conditions and uncertainty associated with the use of the new scour assessment methodology, Baird was retained to design and implement a scour monitoring system. The resulting SCOUR system provides bi-weekly hindcasts of waves and currents as required to estimate scour potential at each pier and define the requirement for seabed surveys. The SCOUR system was installed in 1997, and has led to the identification of scour and the installation of scour protection at two additional piers. Comprehensive reviews of the scour monitoring data were completed by Baird in 2003 and 2011, leading to refinements in the scour assessment methodology and a reduction in the scour monitoring requirements.
The project resulted in the development of a new approach to assess the potential for scour around bridge piers. This method can address complex hydrodynamic, pier geometry and foundation material conditions, but can also be applied to less complicated scour problems.
Whiting, IN, USA
An assessment of storm damage to a rubble mound revetment protecting a park in Whiting, IN, along with the design and construction of emergency repair works and preliminary design development for comprehensive rehabilitation works for the structure.
Lake Nipigon, ON, Canada
Baird was retained to complete the planning, design and construction services to protect 1,400 metres of eroding shoreline on Whitesand First Nation traditional land, located on the north shore of Lake Nipigon. The design consisted of an armour stone revetment and slope stabilization.
