Project engineer Philipp Holzmann, Frankfurt, Germany, 1987—1989, construction manager Dusseldorf, Germany, 1989—1992, Nuremburg, Germany, 1992—1995. Managing director PH Planungsgesellschaft, Frankfurt, 1995—2000. Professor civil engineering University Aachen, Germany, since 2000.
Teacher private university, Witten, Germany, 1996—1999, Technology College, Darmstadt, Germany, 1995.
Member of Center for German and International Law Civil Engineering (member advisory committee), Research Association for Underground Transportation Facilities (president), International Geosynthetics Society (president German chapter, council member), German Society Geotechnical Engineering (board member, president special section on geosynthetics in geotechnics).
1987 - 1989
1992 - 1995