A model test system with a dynamic load device for geotechnical engineering in cold regions is presented.This system consists of a model test tank,a refrigeration device and temperature controller,a dynamic load device,together with sensors and data loggers for detecting stress,deformation,and temperature changes.The system can accommodate soil blocks up to 3 m in length,2.5 m in width,and 1 m in height.The lowest temperature provided by the refrigeration device is-20 ℃.The maximum load provided by the dynamic load device is 100 kN and the vibration frequency of the dynamic load can range from 0.1 to 10 Hz.A number of waveforms,such as sine waves,rectangular waves,triangle waves,and other user-defined waves can be generated by the dynamic load device controller.
Frost heave is one of the main freezing problems for construction in permafrost regions.The Konrad-Morgenstern segregation potential(SP) model is being used in practice for frost heave using numerical techniques.However,the heat release from in-situ and migrated water in the freezing zone could result in some numerical instability,so the simulation of frost fringe is not ideal.In this study,a semi-analytical solution is developed for frost heave prediction of clay soil.The prediction results to the two tests with different freezing mode with clay soil agree well with the tested behavior,which indicates the feasibility of the solution.
