ABSTRACT
The federal motorway A70 in Bavaria crosses a mass movement area of at least 1.5 km length. Several costly reconstruction measures were conducted to remedy the damage, but they could only affect a deceleration of the deformation velocity. Until the relocation of the route is finished, a detailed monitoring program including risk levels acc. to the guidelines of Eurocode 7 (EC7) was installed. Topic of this paper is the interpretation of the complex ground conditions (disintegrated sandstone layer overlying massive clay layer) and corresponding movement process (block spreading). Therefore, measuring results (inclinometer, pore-water pressure and geodetic measurements) were combined with extensive laboratory tests on the clayey material that is decisive for the formation of a sliding surface. Monitoring results shown, that the clay has a high swelling potential and heavy rainfall trigger the movement. Laboratory tests reveal that the clay has distinct inhomogeneity with highly varying soil parameters. Therefore, statitical evaluation has been performed to determine representative input parameters for a slope stability analysis. The stability analysis combines the results of the field and laboratory tests to achieve a deep understanding of the landslide at the motorway A70.
