FPrimeC Solutions Inc. was retained by the client to perform a subsurface investigation for identifying potential voids and cavities at an excavation site in Ottawa, ON. The client had been experiencing difficulty in building up their retaining walls and timber lagging supports as numerous sinkholes had been reported in the area, causing the soil prolife to be unpredictable.  The client wished to first locate all the cavities and voids in the soil, and then fill them to prevent further disruption to the project. FPrimeC was tasked to determine the position of the cavities and report it back to the client, for the purposes of appointing a contracting team the fill the voids based on the areas and locations determined by FPrimeC.

    Ground Penetrating Radar

    The investigation took way, using the Subsurface Mapping GPR GS8000, a Stepped-frequency Continuous-Wave GPR system with a cm-level real-time GNSS positioning system.  A Free Path scan was conducted, covering 80m longitudinally and 6m in width; on both sides of the excavation-pit, with a specific emphasis on identifying potential anomalies (voids and cavities) within the soil profile.