Slides in sensitive clays (also known as quick clay slides) are well known in Norway and are responsible for economic and human losses. The recent landslide that occurred at Gjerdrum on 30th December 2020 confirmed that:
- these landslides present a retrogressive behaviour and successive failures can be observed minutes, weeks and even years after the main failure;
- not only human activities can trigger these landslides, but a combination of natural and human activities is also common.
In the aftermath of these landslides many studies were carried out, but some questions remain still with no answer.
- What do we know about successive failures of old quick clay slides?
- What is the frequency and magnitude?
- How long it will take before the next failure?
- What are the causes that triggered successive failures?
It could be possible to better define the antecedent hydro-meteorological conditions before historical quick clays slides (those registered as caused by natural factors or a combination of natural and human factors)?
The thesis will investigate one of these questions. Landslide data from the national landslide database, historical documents, technical reports, as well as water discharge data and other data from xgeo.no will be used for the analyses. The expected results will be a better understanding of the dynamic behaviour of quick clay slides through time and main causes or/and a better definition of antecedent conditions that have triggered past quick clay slides.
The results of this research will be relevant for hazard mapping, land use plans, landslide early warning systems and emergency response.