Development and application of large-scale multi-functional frozen soil-structure interface cycle-shearing system

In the permafrost regions and artificial frozen soil projects, there are many problems of interface between frozen soils and architectural construction, but there is no related test equipment, which can be used for researches on frozen soil-structure interface. Based on this, a new apparatus called large-scale multi-functional cycle direct shear apparatus for frozen soil-structure interface (DDJ — 1) is developed. The shear system is excellent in many performances: (1) the system can precisely realize the temperature control in the range of 0～-20℃; (2) four normal boundary conditions, including constant stress, constant displacement, constant stiffness and zero stress, can be exerted accurately in the system; (3) various roughnesses of interface can be simulated; (4) two shear forms, circular shear and drab shear, can be provided; (5) the state of failure, thickness and shear displacement of the shear bands in frozen soils can be monitored; and (6) the stress applying, displacement control and temperature regulation can be precisely measured. The test results show that the apparatus can accurately reproduce the mechanical and deformational behaviors of the interface between frozen soils and structures, meanwhile, it can provide a experimental basis and important ideas for carrying out researches on the frozen soil-structure interface.