Sammendrag
Sensitive clays are typically found in Norway, Sweden and Canada and are characterized by a remolded undrained
shear strength which is considerably lower than the intact undisturbed shear strength. In geotechnical engineering
the presence of sensitive clays pose a major challenge. The landslides at Rissa in 1978, and more recently at the
Skjeggestad bridge in Norway, are devastating reminders of the potential threats related to such soils. For the
geotechnical engineer in a construction project it is hence important to 1) determine if there is sensitive clay
present and 2) determine the extent of the quick clay deposit. This is currently done based on interpretations of
soundings and to some extent geophysical methods such as electrical resistivity. However, for verification of quick
clay, sampling and laboratory testing must be performed. Here, a set of updated and new guidelines for
classification of sensitive clays from in-situ measurements is presented. The aim is to provide the geotechnical
engineer with a practical classification tool where all available information is utilized and combined efficiently.
The methods included are CPTU, including measurement of total force, and vane shear testing in combination
with geophysical tools such as R-CPTU, 2D resistivity profiles (ERT) and airborne electromagnetic
measurements (AEM). An extensive database of Norwegian test sites forms the basis for the work. The results
show that the above mentioned site investigation methods holds information that complements each other to
form a solid basis for detecting the location of sensitive clays. In turn this opens for more efficient site
investigations where all available data is interpreted in a systematic manner to produce a reliable mapping of
sensitive clay deposits.
shear strength which is considerably lower than the intact undisturbed shear strength. In geotechnical engineering
the presence of sensitive clays pose a major challenge. The landslides at Rissa in 1978, and more recently at the
Skjeggestad bridge in Norway, are devastating reminders of the potential threats related to such soils. For the
geotechnical engineer in a construction project it is hence important to 1) determine if there is sensitive clay
present and 2) determine the extent of the quick clay deposit. This is currently done based on interpretations of
soundings and to some extent geophysical methods such as electrical resistivity. However, for verification of quick
clay, sampling and laboratory testing must be performed. Here, a set of updated and new guidelines for
classification of sensitive clays from in-situ measurements is presented. The aim is to provide the geotechnical
engineer with a practical classification tool where all available information is utilized and combined efficiently.
The methods included are CPTU, including measurement of total force, and vane shear testing in combination
with geophysical tools such as R-CPTU, 2D resistivity profiles (ERT) and airborne electromagnetic
measurements (AEM). An extensive database of Norwegian test sites forms the basis for the work. The results
show that the above mentioned site investigation methods holds information that complements each other to
form a solid basis for detecting the location of sensitive clays. In turn this opens for more efficient site
investigations where all available data is interpreted in a systematic manner to produce a reliable mapping of
sensitive clay deposits.