1. Chair of Soil Mechanics, Foundation Engineering and Environmental Geotechnics, Department of Civil and Environmental Engineering, Ruhr-Universität Bochum, 44801 Bochum, Germany
2. Department of Civil and Environmental Engineering, Institute of Geotechnics, Technische Universität Darmstadt, 64289 Darmstadt, Germany
3. Department of Civil and Architectural Engineering, Aarhus University, DK-8200 Aarhus, Denmark