Dynamic thermo-mechanical responses of road-soft ground system under vehicle load and daily temperature variation

A complete road-soft ground model is established in this paper to study the dynamic responses caused by vehicle loads and/or daily temperature variation. A dynamic thermo-elastic model is applied to capturing the behavior of the rigid pavement, the base course, and the subgrade, while the soft ground is characterized using a dynamic thermo-poroelastic model. Solutions to the road-soft ground system are derived in the Laplace-Hankel transform domain. The time domain solutions are obtained using an integration approach. The temperature, thermal stress, pore water pressure, and displacement responses caused by the vehicle load and the daily temperature variation are presented. Results show that obvious temperature change mainly exists within 0.3 m of the road when subjected to the daily temperature variation, whereas the stress responses can still be found in deeper places because of the thermal swelling/shrinkage deformation within the upper road structures. Moreover, it is important to consider the coupling effects of the vehicle load and the daily temperature variation when calculating the dynamic responses inside the road-soft ground system.