Site characterisation and some examples from large scale testing at the Klett quick clay research site

Abstract

The Klett research site was developed in conjunction with the new E6 developments south of Trondheim, Norway. The site comprises non-sensitive clay to about 6 m to 8 m and quick clay with significant silt lenses below this down to at least 30 m. The materials encountered are typical of the marine clays found in Scandinavia and North America. Classical geophysical and geotechnical techniques such as total soundings, rotary pressure soundings and ERT proved very useful in characterising the quick clay. The material is particularly susceptible to sample disturbance effects and the work showed that it is important to test any samples as soon as possible after sampling. CPTU data proved particularly useful for the determination of some soil properties as well as general soil classification. Several full-scale experiments have been performed at the site. Pile capacity tests showed that significant ageing effects occurred. Lime-cement column tests, as well as laboratory trials, allowed considerable savings to be made in the amount of binder required for foundations and slope improvement. A full-scale embankment test provided very useful data for the calibration of soil constitutive models.