4 CONCLUSIONS
Through a controlled-temperature direct shear test system, this paper
systematically investigates the shear characteristics of the interface
between frozen soil and concrete under constant normal stiffness
conditions, and arrives at the following conclusions:
(1) With the increase in temperature and water content, the interfacial
curve gradually transitions from a strongly hardening type to a weakly
hardening type. The initial shear stiffness of the interfacial shear
stress-shear displacement curve gradually increases, and the interfacial
shear strength also gradually increases.
(2) In the thawed state, there is no significant change in the curve
morphology as the normal stiffness increases, all exhibiting strong
strain hardening with a relatively small elastic deformation stage. In
the frozen state, as the normal stiffness increases, the curve
morphology transitions from a strongly hardening type to a weakly
hardening type. The initial elastic stage of shearing is more
pronounced, corresponding to a larger displacement. In the residual
stage, the increment of shear stress decreases as the shear displacement
increases.
(3) Under normal temperature conditions, the peak interfacial shear
strength gradually increases with the increase in normal stiffness, and
this trend becomes more pronounced as the normal stress increases. Under
negative temperature conditions, the peak shear strength significantly
increases with the increase in normal stiffness, and this trend becomes
more evident as the temperature decreases. Correspondingly, the
interfacial cohesion and friction angle also increase with the increase
in normal stiffness.