NEW BRUNSWICK ROUTE # 126 (KOUCHIBOUGUAC RIVER BRIDGE NO. 5) REALIGNMENT, RIGHT-OF-WAY AND STAGED CONSTRUCTION TECHNIQUES

The desire to improve Canada’s roadways in the interest of safety is one of the prime focal points in highway and bridge design. Replacement of a bridge structure within a crowded right-of-way can pose interesting challenges for designers and for construction crews, when requirements of maintaining traffic and river flow are taken into consideration. This paper will discuss the innovative approach the New Brunswick Department of Transportation (NBDOT) implemented on the road realignment construction project of Route #126 at the Kouchibouguac River located near Rogersville, New Brunswick. Improved vertical geometry associated with the new highway design for this section of Route #126 required the removal of an existing cast-in-place bridge, a significant increase in road grade elevation at the Kouchibouguac River, maintaining two lanes of traffic by means of three temporary detours over the existing and new bridge structures during the phases of construction, all within the confines of the narrow road right-of-way. A 100 year design life criteria was required for this structure, therefore NBDOT specified a pre-cast concrete segmental arch for the new bridge and mechanically stabilized earth (MSE) for the retaining wall structures. The adjacent property, running parallel to Route # 126 for the length of contract is owned by New Brunswick East Coast Railway Company Inc. No impact on the railway bridge structure or the railway embankment was permitted, therefore an MSE wall with a pre-cast concrete traffic barrier was constructed to retain highway embankment slopes and to remain within the designated provincial right-of-way. The new bridge structure was spanning the Kouchibouguac River, which was environmentally sensitive. In-stream construction activity was strictly prohibited outside the June 1 to September 30 window and in an effort to protect fish habitat, work areas were isolated from the stream flow. Finally, this paper will illustrate the various construction stages, erection technique of the TechSpan arch, detours implemented for road safety considerations and human factors involved in the successful completion of this project.