Journal of Cold Regions Engineering

The effect of artificial salting on the freezing behavior of a silt soil was investigated through open‐system unidirectional freezing tests. Specimens were prepared in 5‐cm‐by‐15‐cm segmented columns. Initial soil dry densities ranged from $1.5-2.0\mathrm{gm}/{\mathrm{cm}}^3\text{.}$ Artificial salting was applied by wetting the soil with salt solutions before compaction. Sodium chloride solutions at concentrations of 0.1 N, 0.25 N, and 0.5 N were used. Specimens were subjected to a top and a bottom temperature of $-10°C$ and $+4°C\text{,}$ respectively. The results show that artificial salting is an effective treatment in reducing rate and magnitude of heave, moisture transfer to the frozen zone, and depth of frost penetration. The freezing behavior of the soil tested was also influenced by the degree of compaction, suggesting that a critical density exists at which maximum frost‐heave is reached. Increasing or decreasing soil density from this value resulted in reduction of frost‐heave. An explanation of the soil behavior was attempted.

The magnitude of the force acting on a structure during an ice‐structure interaction is obtained using an approach based on linear elastic fracture mechanics. The magnitude of the ice‐structure interaction force makes the ice fail in one of many possible failure modes of ice. Crack propagation, which is one of the most significant failure modes of ice, is analyzed in this work. A crack in an ice sheet will propagate when the stress intensity factor equals the fracture toughness of ice. The ice sheet is assumed to contain a system of cracks having the same length and orientation and equally spaced in both directions. The magnitude of the contact stresses acting on the structure, therefore, makes the stress intensity factor at the tip of the critical crack reach the fracture toughness of ice. Results of the analysis show that fracture solutions give contact stresses that fall within the range of measured values and depend on the crack densities and orientations as well as on the structure shape.

A multistage, lateral, pile‐load creep test is carried out in a frozen sand maintained at $-3°C\text{.}$ The pile is a tubular pipe, 150 mm square and 1,800 mm long. A series of plate load cells is mounted along the primary bearing face of the pile. Application of lateral loads of 35, 65, and 115 kN result in attenuating creep, whereas a lateral load of 145 kN leads to accelerating creep. The immediate components of pile displacement increase approximately linearly with applied load, while the creep components increase exponentially. Generally, the soil reaction forces near the ground surface decrease as the result of pile creep, and those further down the pile increase. Moduli of horizontal subgrade reaction computed on the basis of the measured soil reaction forces and the pile displacement are found to vary with applied pressure and creep. Magnitudes based on immediate displacements range from 1 to $7.5\mathrm{GN}/m^3\text{,}$ while those based on total displacements range from 0.3 to $2\mathrm{GN}/m^3\text{.}$