Geospatial modelling of shear-wave velocity and fundamental site period of Quaternary marine and glacial sediments in the Ottawa and St. Lawrence Valleys, Canada

Susceptibility modelling of seismically induced effects (landslides and rock falls) integrated to rapid scoring procedures for bridges using GIS tools for the Lowlands of the Saint-Lawrence Valley

“…Bedrock outcrops in few regions but predominant geology is composed of glacial and post-glacial unconsolidated deposits. It is mainly dominated in the north-west by metamorphic and igneous rocks dated from Precambrian, in the centre by sedimentary rocks from the Iapetus ocean (Ordovician-Silurian) and in the south-east by the metamorphic rocks of Appalachians orogeny (Cambrian-High Ordovician) (Nastev et al 2016). Till deposits (identified by T in Figure 1), which are predominant at the bottom of the quaternary deposits, are very heterogeneous with a large variety of grain size cemented by a compacted silty or sandy silt matrix (Russell et al 2011;Nastev et al 2016).…”

“…It is mainly dominated in the north-west by metamorphic and igneous rocks dated from Precambrian, in the centre by sedimentary rocks from the Iapetus ocean (Ordovician-Silurian) and in the south-east by the metamorphic rocks of Appalachians orogeny (Cambrian-High Ordovician) (Nastev et al 2016). Till deposits (identified by T in Figure 1), which are predominant at the bottom of the quaternary deposits, are very heterogeneous with a large variety of grain size cemented by a compacted silty or sandy silt matrix (Russell et al 2011;Nastev et al 2016). During the last deglaciation (between 18,000 and 12,000 years BP), the moraine was eroded by the eskers and replaced by glaciofluvial (GF) or glaciolacustrine (GL) deposits (Parent and Occhietti 1999;Russell et al 2011;Savard 2013).…”

“…During the last deglaciation (between 18,000 and 12,000 years BP), the moraine was eroded by the eskers and replaced by glaciofluvial (GF) or glaciolacustrine (GL) deposits (Parent and Occhietti 1999;Russell et al 2011;Savard 2013). GF deposits are mainly composed of sands and gravels (Nastev et al 2016) while GL are mostly composed of clays (Parent and Occhietti 1988). During the interglacial stage, glacial deposits were covered by up to 30 m of marine clays (M) (Lefebvre 1986;Nastev et al 2016).…”

“…GF deposits are mainly composed of sands and gravels (Nastev et al 2016) while GL are mostly composed of clays (Parent and Occhietti 1988). During the interglacial stage, glacial deposits were covered by up to 30 m of marine clays (M) (Lefebvre 1986;Nastev et al 2016). For the region of study, the source of these deposits is mainly the Champlain sea dated between 12,000 and 10,000 years BP (Parent and Occhietti 1999;Savard 2013).…”

“…Group B includes weakly cemented rocks and soils (sandy soils and poorly cemented sandstone, c 0 = 0, ɸ 0 = 35 ), such as sand, silt and gravels including alluvial (A) (Nastev et al 2016), eolian (E) Figure 2. Factors used for landslides and rock falls susceptibility mapping.…”