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.

The surge in the number of cars has generated enormous numbers of waste tires in recent years. How to utilize the waste tires in engineering construction in an environmentally friendly way is a problem that China and many other countries have to tackle. In this study, the dynamic response of a retaining wall reinforced with combined waste tires and geogrid was experimentally investigated. The simulated dynamic vehicle load was exerted by a self-developed loading system. The performance of the combined waste tire and geogrid reinforcement for a retaining wall system was compared with that of systems reinforced with biaxial geogrid, geocell, and waste tire. The accelerations and vertical earth pressures at selected locations within the model and deformations of different reinforced retaining walls subjected to simulated dynamic vehicle loads were measured. The test results demonstrated that the combined waste tire and geogrid reinforcement enhanced the dynamic performance and stability of the retaining wall. Furthermore, the influences of tire spacing, vehicle speed and loading magnitude on the dynamic responses of the reinforced retaining wall system also were examined. The findings drawn from this study along with the derived correlations likely will benefit both relevant engineering practice and the recycling of waste tires.

The study of dynamic responses of a layered road system under heavy duty vehicle is one of the most important areas in the field of transportation. This paper introduced a field testing programme of traffic-induced road vibration in Guangxi, China and investigated the subgrade vibration induced by a heavy duty truck with various axle weights and speeds through a series of field tests. The vertical stress and acceleration of the road subgrade at different depths from the tests were presented and analysed. According to the test road, a semi-analytical model of the layered road was established via the stiffness matrix method and the heavy duty vehicle was simulated by ten moving rectangular load pressures. Numerical results in the space domain were derived by performing Fast Fourier Transform and were used to compare its results with the field measurements. The agreement between the numerical and the field results was good, which indicates that the proposed method is useful in predicting the dynamic stress and acceleration of a multi-layered road structure.

In this paper, a full vehicle–track–ground coupling model is presented to evaluate the dynamic response of the subgrade due to high-speed trains. The vehicle was modeled as a multibody. The track was considered as an Euler beam. The ground soil was regarded as two elastic layers and a poroelastic half-space, taking into account a complete subgrade/subsoil system. The wheel–track interaction was considered by using the linear Hertzian contact theorem. The stiffness matrix method and the Fourier transform were introduced to deal with formulations of the coupling model in a transformed domain, and the time-domain solutions were derived by using the fast Fourier transform algorithm. The wheel–track contact forces and the dynamic responses of the subgrade were studied, and the effects of the rail irregularity and the properties of the subgrade bed were then investigated. It was concluded that the dynamic responses of the subgrade are significant compared with responses induced by the axle load and are influenced greatly by rail irregularity and parameters of the subgrade bed.