UCI was called on by Imperial Oil and its consultants, SNC-LAVALIN, to inspect the corroding product pipe tunnel under Vidal Street in Sarnia and recommend a solution to extend its life.
Inspection revealed an original liner plate tunnel with a corrugated steel pipe connected to it to accommodate a road widening many years ago. Both tunnel types had areas of severe corrosion which jeopardized the structural integrity of the tunnels. Any collapse onto the active petroleum product piping would be a serious situation.
The recommended solution is the building of slightly smaller tunnel liner sections within the existing corroded tunnel at three locations. The annular space between the existing and new culverts will be filled with concrete grout.
Working conditions within the tunnel are difficult. The multitude of pipes and the necessity of workers carrying self contained breathing apparatus and dragging an extraction line to meet Imperial Oil confined space requirements will severely impede productivity.
The work is being fast-tracked for completion in late 2010.