Development Of A Methodology For Quick Clay Mapping

Quick clays involve considerable risks because small initial slips may evolve into large landslides involving the entire quick clay formation. Most large clay slides in Sweden, Norway and Canada have been in quick clay areas. It is therefore necessary to develop cost-effective methods for mapping the extent of quick clay formations and areas with probable quick clay. The most important areas are those with existing infrastructure and buildings as well as areas planned for exploitation. The methodology should be well-designed in proper steps with different levels of accuracy and include overview studies of topographical and geological methods, detailed geophysical and geotechnical ground investigations, as well as airborne geophysical methods with greater coverage but less accuracy. Three areas in southwest Sweden and one area in the northeast have been selected for this study. In these areas, locations with and without quick-clay have been identified by geotechnical sounding and sampling. Airborne electromagnetic (ATEM) measurements have been carried out in all four areas. The preliminary results from the first two areas, which are presented in this paper, show a reasonable correlation between the different methods used.