Application of a simplified model for the prediction of pore pressure build-up in sandy soils subjected to seismic loading

The most common procedures for predicting pore pressures generated by earthquake loading in saturated soil deposits are usually calibrated on laboratory data obtained in strain- or stress-controlled cyclic tests. A new stress-based approach under one-dimensional conditions is proposed, based on a single variable, called ‘damage parameter’, allowing the direct generalization of the cyclic test data to irregular stress histories. This method may greatly simplify dynamic response analyses of saturated sand deposits with both total and effective stress approaches, by removing the need for evaluating equivalent uniform stress cycles and avoiding to measure complex soil parameters for sophisticated plasticity-based models. Due to its simple and explicit formulation, the model can be incorporated in a time domain program to perform coupled effective stress dynamic analyses. Its implementation in a nonlinear 1D code has been examined through the analysis of a case study of a dyke damaged during the 2012 Emilia seismic sequence.