Risk Mitigation when Microtunneling in Adverse Soil and Rock Conditions: A Case Study

摘要

In 2010 Stantec was awarded the environmental assessment (EA), detailed design and contract administration for the City of Kawartha Lakes’ Northwest Trunk Sewer project, which included installation and replacement of 4.5 km of gravity sewer and 6 km of forcemain. The City of Kawartha Lakes relied on Federal Infrastructure stimulus funding for this project which was provided with strict project completion timelines. This led to an accelerated project schedule. To facilitate efficient construction schedules, the project was split into six (6) independent contracts, the most complex of which included a twin 500 mm diameter concrete pressure pipe (CPP) forcemain installation over a 220 m crossing of the Scugog River by microtunneling. Given the scale of the project, the presence of provincially significant wetlands in the region, and potentially contaminated sediments across the Scugog river crossing, it was imperative to minimize risks and project delays.