Researchers Reveal Mechanical Properties of Interface between Warm Frozen Silt and Cemented Soil
Chinese researchers recently established an elastoplastic damage constitutive model for the interface between cemented soil structure and warm frozen soil, providing a basis for the numerical simulation and theoretical calculation of the structures in warm frozen ground.
Previous studies on the soil-structure interface mainly focused on unfrozen soil environment, which is not suitable for frozen soil. Furthermore, few studies have been conducted on mechanical properties of the interface between cemented soil and warm frozen soil, and neither microscopic deformation mechanism nor constitutive model has been established in a real sense.
By designing direct shear tests of the cemented soil-frozen soil interface under the influence of various factors at negative temperature, researchers from Northwest Institute of Eco-Environment and Resources of Chinese Academy of Sciences (CAS) investigated mechanical properties on the cemented soil-warm frozen soil interface.
They abstracted the frozen silt with high ice content on the interface as the binary medium composed of bonded elements and frictional elements on the mesoscopic scale. This model was established based on the micro-deformational mechanism of the interface between cemented soil and warm frozen soil, and combined with the theory of breakage mechanics for geomaterials and the binary medium model.
The researchers also established equations of the breakage rate and stress sharing rate, and discussed the micro deformational mechanism and macro mechanical characteristics of the structure-soil interface using a binary medium model. Finally they established an elastoplastic damage constitutive model for the cemented soil structure-frozen soil interface.
The results shows that the damage constitutive model of the interface unveils the microscopic damage mechanism and meso-mechanical properties of the cemented soil-frozen soil interface and simulates the whole process of stress–displacement curve of the interface, especially the strain softening characteristics of the interface.
Furthermore, it has good applicability to simulate the stress–displacement relationship of cemented soil-warm frozen soil interface.
The research has been published in Transportation Geotechnics as an article entitled Mechanical behavior and constitutive relation of the interface between warm frozen silt and cemented soil. This work was financially supported by the National Natural Science Foundations of China (41971086).
State Key Laboratory of Frozen Soil Engineering, Northwest Institute of Eco-Environment and Resource, Chinese Academy of Sciences, Lanzhou, China.