Leda clay—deposited by the ancient Champlain Sea—has an extremely high sensitivity ratio, meaning it loses nearly all its shear strength when disturbed. Undisturbed, it behaves like firm soil; remolded, it flows like heavy liquid. This property causes retrogressive flowslides where an initial small failure triggers a chain reaction that can destroy hectares of terrain in minutes. GSI's chemical stabilization and drainage programs reduce both the clay's sensitivity and the pore pressures that trigger initial failure.

GSI injects lime, cement, or engineered chemical compounds into sensitive clay deposits through a grid of injection points. These additives create cementation bonds between clay particles that permanently increase the soil's shear strength and reduce its sensitivity. The treatment is designed based on laboratory testing of site-specific clay samples, ensuring the chemical program matches the actual soil mineralogy. Combined with drainage to reduce pore pressures, chemical stabilization transforms unstable clay slopes into engineered assets.

Along Route 138 and other North Shore corridors, GSI installs rock bolt systems that anchor unstable blocks within the Canadian Shield's fractured formations, attenuator barriers that absorb the kinetic energy of falling rock before it reaches the road, and draped mesh networks that contain debris on the slope face. Our rope access crews perform systematic scaling to remove loose rock, and our spider excavators access terrain between the highway and cliff face where conventional equipment cannot operate.

Yes. Historically, sea ice along the Gaspésie coast provided a natural buffer that protected shorelines from winter storm waves. As ice formation decreases and duration shortens, exposed coastlines absorb more wave energy during the most energetic storm season. GSI's coastal protection designs account for current erosion rates and projected future reductions in ice cover, engineering revetment and stabilization systems that perform under conditions that did not exist when much of the existing shoreline infrastructure was built.

GSI's engineering team understands Quebec's distinct regulatory environment, including the Ministère de l'Environnement requirements, the Politique de protection des rives, du littoral et des plaines inondables, and federal Fisheries Act provisions. Our design/build scope includes regulatory compliance from the project planning phase, ensuring that construction methods and materials meet all applicable standards without the delays that occur when permitting is treated as an afterthought.

GSI maintains 24/7 emergency response capability for landslide events in the St. Lawrence Valley and across Quebec. When a sensitive clay failure occurs or is imminent, our teams coordinate with Quebec's Ministère des Transports to assess the failure, establish exclusion zones, and design stabilization that prevents retrogressive expansion. Our emergency line at (855) 599-5217 connects directly to experienced project managers who mobilize crews and equipment immediately.