COXHEATH ROAD BRIDGE RECONSTRUCTION STAGED CONSTRUCTION USING INNOVATIVE GEOTECHNICAL DESIGNS

With increased traffic volumes and limited space to rebuild ageing bridge structures, engineers look for innovative methods to resolve design challenges. The Nova Scotia Department of Transportation (TPW) needed to reconstruct the Coxheath Road Bridge over Highway #125 in Sydney, Nova Scotia due a combination of repairs and additional exit ramps required near the Sydney River area to relieve traffic congestion at the Kings Road Interchange. This paper will illustrate the innovative geotechnical design approach the NSDOT incorporated in the reconstruction of the bridge. It will explain and highlight the various aspects the stage construction to allow continuous traffic flow on the Coxheath Road Bridge and Highway #125 with a minimal traffic stoppage. The application of mechanically stabilized earth (MSE) for retaining structures is ever increasing. In the Coxheath Road Bridge Reconstruction, the contractor chose the material known as Terratrel, designed and manufactured by the Reinforced Earth Company Ltd. (RECO), for temporary abutment walls as a wire-faced MSE system to construct, disassemble and then recycle the internal gravel as the most efficient method. The temporary wire-faced Terratrel system was designed as a true bridge abutment capable of withstanding the launching load of the temporary truss bridge used to re-route the Coxheath Road traffic. Once the detour was in place, the exiting structure was demolished and a new permanent bridge was constructed on a RECO supplied concrete –faced MSE system called Terraclass. The new design allowed for exit ramps to relieve the congestion issues in this area.