Geotechnical Investigation for the Kingston Breakwater
Just west of downtown Kingston, Ontario, the City of Kingston reimagined the Confederation Basin breakwater as an accessible, pedestrian-friendly waterfront promenade (Visit Kingston | Kingston's Beautiful Breakwater Park). Originally constructed in the late 1980s, the breakwater consisted of armour stone, granular fill, and a granite-cappedstructure that protected the marina and public docking facilities along the shoreline. To support the design of a new landmark public space, Cambium was retained by Kehoe Marine to complete a comprehensive geotechnical investigation and foundation assessment.
Cambium and Kehoe conducted a three-part investigation to better understand the breakwater’s composition, subsurface conditions, and foundation requirements for the proposed elevated promenade.
Rock Probing: Cambium provided oversight for a detailed rock probing program involving 16 probe locations along the inner and outer shoreline of the breakwater. Using vibratory-driven tube piles, the team assessed the depth and profile of underlying bedrock, identifying significant variations in bedrock elevation and subsurface conditions. The results helped the design team refine the promenade alignment and determine appropriate pile lengths and foundation requirements.
Pile Testing: Cambium observed a pile driving program involving sheet piles, tube piles, and round piles of varying diameters installed at multiple locations across the breakwater. The testing evaluated pile performance during installation, established practical refusal criteria, and confirmed the ability of piles to achieve competent bedrock support. These findings provided critical input for the design of the promenade’s pile-supported structure.
Geotechnical Investigation: Cambium advanced three boreholes and completed laboratory testing to characterize the breakwater fill, native soils, and bedrock. The investigation revealed varying subsurface conditions, including rock fill, granular deposits, marine silts and clays, and bedrock depths ranging from approximately 4 to 21 metres below surface. The results were used to develop geotechnical design parameters, seismic site classifications, and foundation recommendations for the promenade.
Through close collaboration with Kehoe Marine and the City of Kingston, Cambium delivered the technical data needed to advance design with confidence. By combining rock probing, pile testing, and geotechnical engineering into a coordinated investigation program, Cambium helped reduce design uncertainty and support the successful planning of a resilient waterfront destination for residents and visitors alike.
