In this paper, an elastoplastic model with a non-smooth friction mechanism and a volumetric mechanism is proposed to determine loads on pipes due to relative movements. The model requires the input of the stress-strain curves obtained directly from laboratory stress path on the particular soil studied, in the form of discrete data points. Various axisymmetric triaxial paths are simulated in order to demonstrate the good performance of the proposed model. In addition, several finite element analyses of soil-pipeline interaction under lateral loading have been carried out.