Towards geophysical and geotechnical integration for quick‐clay mapping in Norway

Abstract

Quick clay is a known hazard in formerly‐glaciated coastal areas in e.g., Norway, Sweden and Canada. In this paper, we review the physical properties of quick clays in order to find a suitable, integrated and multi‐disciplinary approach to improve our possibilities to accurately identify the occurrence of quick clay and map its extent both vertically and laterally. As no single geophysical method yields optimal information, one should combine a variety of geophysical methods with geotechnical data (in situ measurements using Cone Penetration Testing (CPTU), Seismic CPTU (SCPTU) and Resistivity CPTU (RCPTU); laboratory tests) for an in‐depth quick‐clay assessment at a given site. In this respect, geophysical data are used to fill the gaps between geotechnical boreholes providing ground‐truth. Such an integrated and multi‐disciplinary approach brings us closer to 2D or pseudo‐3D site characterization for quick clays and as such, an improved assessment of the potential hazard they pose. The integrated approach is applied in practice on two Norwegian quick‐clay sites. The first site, Hvittingfoss, was remediated against potential landslides in 2008 whereas the second one, Rissa, was the scene of a major quick‐clay landslide in 1978, quick clays being still present over a large area. The collected data and preliminary site characterizations illustrate the high diversity as well as the complexity and clearly emphasize the need for higher resolution, careful imaging and calibration of the data in order to accomplish the assessment of a quick‐clay hazard.

Airborne mapping of sensitive clay—stretching the limits of AEM resolution and accuracy

“…; Sauvin et al . ). In addition, groups in Sweden and Canada, where quick clay is commonly referred to as Leda or Champlain Sea clay, have studied the applicability of geophysical methods (Dahlin et al .…”

An overview of multimethod imaging approaches in environmental geophysics

“…Geophysical techniques are widely used to characterize these natural systems at scales that are representative of the key processes defining these systems, covering the pore to the catchment scale, and are known to supplement and link conventional local sampling approaches (e.g., by using boreholes) with observations from remote sensing. Applications range from characterizing subsurface hydrological features and critical zone properties (e.g., Holbrook et al, 2014;Thayer et al, 2018;Hausmann et al, 2013;Moravec et al, 2020;Yamakawa et al, 2012), to natural hazards such as landslides (e.g., Capizzi and Martorana, 2014;Sauvin et al, 2013;Sass et al, 2008;Bièvre et al, 2012) or sinkholes (e.g., Carbonel et al, 2014;Gómez-Ortiz and Martín-Crespo, 2012), permafrost degradation (e.g., Parsekian et al, 2019;Mollaret et al, 2020;Steiner et al, 2021), or geological CO 2 storage (e.g., Carcione et al, 2012;Bergmann et al, 2016).…”

Geotechnical site characterization using multichannel analysis of surface waves: A case study of an area prone to quick‐clay landslides in southwest Sweden

“…They have extensively been studied by geotechnical and resistivity methods (Dahlin et al 2013;Löfroth et al 2011;Lundström, Larsson and Dahlin 2009;Solberg et al 2012Solberg et al , 2016Wang, Malehmir and Bastani 2016), while only a few studies report the usage of surface-wave dispersion analysis for different investigations on quick clays (e.g. Comina et al 2017;Donohue et al 2012;Long, Wood and L'Heureux 2017;Sauvin et al 2013). Some of the most recent works on quick clays (leached clays) revealed that these materials cannot be distinguished from unleached clays using only shear-wave velocity (VS) measurements (Long et al 2017).…”