1. Inst. for Geotechnical Engineering, Leibniz Univ. of Hannover, 30167 Hannover, DE e-mail: j.albiker@web.de
2. Inst. for Geotechnical Engineering, Leibniz Univ. of Hannover, 30167 Hannover, DE (Corresponding author) e-mail: achmus@igth.uni-hannover.de
3. Inst. for Geotechnical Engineering, Leibniz Univ. of Hannover, 30167 Hannover, DE e-mail: frick@igth.uni-hannover.de
4. Inst. for Geotechnical Engineering, Leibniz Univ. of Hannover, 30167 Hannover, DE e-mail: FalkA.Flindt@gmx.de