Journal of Cold Regions Engineering

This paper presents the formulation of a one-dimensional river-ice simulation model RICEN. The model consists of two major parts: (1) An unsteady flow model for a channel network with ice; and (2) a thermal and ice condition simulation model. The model simulates the water-temperature variation along the river, including supercooling; frazil-ice concentration distribution; anchor-ice growth, decay, and release; surface ice transport; ice-cover progression; undercover ice transport, deposition, and erosion; thermal growth and decay of ice covers; and ice-cover stability.

This paper presents the results of model calibration and a parametric study of the ice-jamming processes in the Tonawanda Channel of the upper Niagara River using the one-dimensional river-ice model RICEN. The model is calibrated using observations and data from historical ice-jam events. A parametric study is carried out to examine the effects of various weather and flow conditions on ice-jam formation and the ice jam's concomitant effects on the flow characteristics.

An 18.2-ha coal tailings impoundment that reached full capacity in 1989 has since been undergoing reclamation activities. The impoundment is sectioned into coarse, intermediate, and fine tails regions. The fine tails region, which consists of saturated silt and clay-size soil and coal particles of high void ratio and negligible shear strength, offers unique problems in terms of reclamation to a dry-surface landscape condition. Freeze-thaw consolidation and dewatering is an effective process for transforming these fine coal tails to a condition of a weak soil with measurable shear strength. Consolidation of the fine tails is found to occur both within and below the frost front. Within the frozen zone, localized moisture migration results in the development of a three-dimensional consolidated soil ped and ice-lense structure. Upon thaw, the consolidated peds settle by gravity, with the water escaping to the surface through the fissured soil ped structure. Thermal-induced suction gradients developed at the advancing frost front result in moisture migration and dewatering of saturated fine tails below the frost front. These two freeze-thaw consolidation and dewatering processes are described, along with models for predicting potential volumes of freeze-thaw treated material for given climatic conditions. Field results showing the significance of these processes on the dewatering and strength enhancement of fine coal tails are also presented. This dewatering and strength development provides the opportunity to implement dry rather than wet landscape reclamation procedures during reclamation of these waste-storage facilities.

Construction in remote Arctic locations is made more difficult and expensive by the need to bring to site bulky building materials. This need can be reduced by the use of ice-soil mixtures. The strength of this reinforced ice is a function of the percentage of reinforcing soil mixed with the ice. To determine this function, beams of sand-reinforced ice were made, with volume percentage reinforcement of sand between 1.4 and 66.9%. The beams were loaded in bending, at a crosshead displacement rate of 50 mm/min and a temperature of −5°C. All samples failed in a brittle manner. The bending strength increased with increasing reinforcement. This behavior is explained by a simple model, extending the work of Nixon and Weber (1991), which assumes that failure arises from the propagation of flaws within the ice matrix. The model, which is semiempirical, describes the observed bending strength behavior very well. Further work is required to refine the model and account quantitatively for the effect of unfrozen water on the beam strength.