1. Swiss Reinsurance Company, Zurich, Switzerland; formerly, Research Associate, Laboratory of Hydraulic Constructions (LCH), Civil Engineering Dept., Ecole Polytechnique Fédérale de Lausanne, Station 18, 1015 Lausanne, Switzerland.
2. Professor, Laboratory of Hydraulic Constructions (LCH), Civil Engineering Dept., Ecole Polytechnique Fédérale de Lausanne, Station 18, 1015 Lausanne, Switzerland (corresponding author).