BRAMPTON, ON

407 ETR Over Gorewood Drive

Highway 407ETR Over Gorewood Drive is a single-span bridge, originally constructed in the early 1980s in advance of the Highway 407 Design-Build project.

TRANSPORTATION

The bridge had conventional expansion joints at each abutment, with full-heigh, reinforced-earth abutments. Over time, the expansion joints closed up and became ineffective due to damage to the seal.

The 407ETR determined that the joints should be removed and replaced with semi-integral abutments and that the work should be completed during weekend partial closures. The critical design considerations included methodology for completing the work in the limited time, traffic management in the partial closure, and durability of the completed rehabilitation. The timing of the construction window was critical in order to maintain the high level of service delivered by 407ETR.

Entuitive, with BTE, elected to put the project through a Value Engineering exercise led by BTE with participation from potential contractors for the work and the owner’s operational staff. Our team developed alternate designs for consideration with sufficient information to clearly indicate the construction work required prior to the meeting. These were presented and discussed, with further alternates being developed. The process yielded valuable insight into the vulnerabilities of the original concept which were translated into significant improvements to the project design.

The process of design improvement continued in the implementation of the project with ongoing discussions with the selected contractor to identify and minimize time on critical path tasks.

Unusual aspects of the completed design include incorporation of a steel link plate to join the approach slab to the structure rather than providing a conventional extension of the bridge structure, incorporating rapid strength gain concrete in the repair work with waterproofing selected to be compatible with the young concrete, and creation of safe work areas along the barriers to isolate critical work items. All these items were critical in reducing the timing risk.