The elastic response of a Champlain Sea clay deposit under test embankment loading conditions in Beauharnois, Quebec

ABSTRACT: Two test embankments were constructed and instrumented over a Champlain Sea clay deposit in Beauharnois, Quebec, in 2017. The general soil stratigraphy of this area consists of a layer of organic soil followed by a 25 m deep, highly compressible Champlain Sea clay deposit. Below a depth of approximately 4 m, the clay is classified to be extra sensitive to quick and over-to-normally consolidated. The test embankments were 2 m and 3 m in height and both had plan areas of 50 m by 50 m. The instrumentation included vibrating-wire settlement gauges and multi-stage vibrating-wire piezometers, both equipped with data-loggers to collect pore-water pressures and ground settlements. The embankments were constructed and maintained for about four months. Primary consolidation was not initiated during the monitoring period; however, ground surface rebound measurements were obtained as the embankments were removed. In addition, an interpretation of the rebound measurements was completed to estimate the aggregate elastic modulus of the soil deposit.