SASW for G-determination in Swedish glacial clays

During the last ten years the building activities in Sweden have been focusing on infrastructure projects like tunnels, railroads, highways and bridges. Many of these projects have not only been extensive but also located in places with a less known geology and especially geotechnically or mechanically Iittle known. A few of these projects have been carried out (eg the Öresund link, City tunnel in Malmö) or are under construction, in the most southern part, Scania, where the geology is quite different from the rest of the country. The south-western part of Scania is typically built up by a few meters of a stiff clay till on top of a limestone basement. Due to the size and the type of constructions, this Iimestone often has to be penetrated, if not by the construction itself so definitely by the different geotechnical investigations carried out before each project. However, the heterogeneous sedimentary limestone, varying from very soft silty layers to the hardest flint nodules, has demonstrated that many of the traditional Swedish methods are less favourable for the different purposes. Therefore, in this project the applicability of the geophysical method SASW, Speetral Analysis of Surface Waves, on Swedish ground was tested, [Svensson M, 1998]. Due to lack of methods applicable to sedimentary rock giving cornparable results, two different clay materials were tested.