1. Dept. Geotech. Engrg., Univ. Napoli Federico II, Via Claudio 21, 80121 Napoli - Italy,.
2. Associate Professor, Dept. Civ. Engrg., 2nd Univ. Napoli, Via Roma 29, 81031 Aversa (CE) - Italy,.
3. Researcher, Dept. Geotech. Engrg., Univ. Napoli Federico II, Via Claudio 21, 80121 Napoli - Italy,.
4. Full Professor, Dept. Geotech. Engrg., Univ. Napoli Federico II, Via Claudio 21, 80121 Napoli - Italy,.