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 theCity of Kawartha Lakes’ Northwest Trunk Sewer project, which included installation and replacement of 4.5 km ofgravity sewer and 6 km of forcemain. The City of Kawartha Lakes relied on Federal Infrastructure stimulus fundingfor this project which was provided with strict project completion timelines. This led to an accelerated projectschedule.To facilitate efficient construction schedules, the project was split into six (6) independent contracts, the mostcomplex of which included a twin 500 mm diameter concrete pressure pipe (CPP) forcemain installation over a 220m crossing of the Scugog River by microtunneling. Given the scale of the project, the presence of provinciallysignificant wetlands in the region, and potentially contaminated sediments across the Scugog river crossing, it wasimperative to minimize risks and project delays.