Effects of excess pore water pressure generation on soil seismic behaviour in a sandy deposit at Nocera Scalo, Italy

ABSTRACT: To highlight soil non linearity effects due to excess pore water pressure generation on soil response and liquefaction in a sandy deposit located in Central Italy, a stress-strain analysis was performed both in terms of total and effective stresses, by using DESRAMOD computer code. This paper illustrates the results of a comparison of the two stress-strain approaches. The analyses were carried out on the subsoil of the hamlet of Nocera Scalo, one of the villages most damaged by the seismic crisis of September- October 1997, Two sites within the deposit were selected for the application of stress-strain procedures. The dynamic initial and strain dependent parameters, the excess pore water pressure time history and the other properties necessary for numerical computation were determined using experimental in situ and laboratory investigations, including soundings, crosshole and downhole testing, laboratory dynamic tests with cyclic triaxial apparatus, resonant column and torsional shear equipment, and non standard oedometric tests. In this work, the results of the experiments and of total and effective stress analyses are presented.