Evaluation and Analysis of the Traffic Load-Induced Settlement of Roads on Soft Subsoils with Low Embankments

A large number of laboratory triaxial experiments were performed to evaluate the likely cumulative settlement of a low embankment road on soft subsoil due to the traffic loads, for the purpose of determining the undrained cumulative strain and cumulative pore-water pressure for different loading conditions. A cumulative settlement model of soft subsoil was then derived with the provision for dynamic stress, confining pressure, initial static deviatoric stress, number of load cycles, and loading frequency. Based on a particular vehicle-road-ground coupling model, the dynamic stress induced by traffic loads, which has a great influence on the cumulative settlement of soft subsoil, is given in explicit form. The cumulative settlement of a road with a low embankment was evaluated, and the results were compared with the field data. The calculated results agreed well with those from the field, which implies that the method proposed in this paper can give precise predictions of the likely cumulative settlement of low embankment roads on soft subsoils due to traffic loads. Moreover, a parametric study was conducted using numerical computation, and the results show that the vehicle types and the pavement unevenness parameters have a major influence on the settlement caused by traffic loads. The influences of the pavement and embankment properties on the cumulative settlement also are significant.