ABSTRACT
A reduction in the local groundwater table surrounding a mine, in the Abitibi-Témiscamingue region of Quebec, Canada, has led to dissipation of porewater pressure and displacement of the ground surface. The mechanical behavior of the site’s fine-grained soil has been studied in the laboratory (consolidation tests) and in-situ tests, particularly cone penetration tests (CPT). Additionally, displacements of the ground surface have been monitored for over 10 years. The consolidation settlements due to the groundwater table drawdown were calculated based on tip resistance values measured during the CPT. By comparing the calculated magnitudes and trends of vertical displacement with measured values, the consolidation calculation method using CPT data was validated. At some locations, there was a good match between the calculated and measured trends. At other survey monuments, the measured displacements were greater than calculated values. It was concluded that additional mechanisms were contributing to the displacements. The possible influence of these mechanisms varies spatially within the studied site.
