Showing papers in "Cold Regions Science and Technology in 1989"

TL;DR: In this paper, the formation of basal ice crystal structure is discussed, incuding the large crystal multi-maxima fabric ice and its flow properties, and results for uniaxial compression and simple shear are presented.

TL;DR: In this paper, a mechanistic model based on differential freezing in macro- and micro-pores of a clayey silt was used to investigate the effect of repeated freezing and thawing on the structure of the silt.

TL;DR: In this paper, the elastic deformation characteristics of a number of natural ice types have been determined using five single crystal compliances, and the analysis provides a basis on which measured values of the elastic moduli of various types of ice can be compared.

TL;DR: In this article, a simple operational model for estimating wet snow loads on overhead power lines is proposed, which can be used in mapping the wet snow load risk by routinely measured meteorological data.

TL;DR: In this article, it is argued that unconsolidated ice rubble undergoing continuous shear deformation is essentially cohesionless; i.e., in terms of the Mohr-Coulomb failure criterion, it should not exhibit a cohesive intercept at zero confining pressure and at large shear deformations.

TL;DR: In this paper, a new model for the ice-induced vibration of offshore structures is developed for the dynamic equations of equilibrium for the structure and the undamaged ice field coupled by a nonlinear element describing the crushing and clearing processes at the ice structure interface.

TL;DR: In this paper, the authors used Mie electromagnetic scattering theory, knowledge of the interception geometry formed by a snow particle and the beam and estimates of the snow particle size frequency distribution, a simple technique for calculating the blowing snow flux was developed and tested.

TL;DR: In this paper, a differential model for the pure flow of polycrystalline ice is proposed based on the concept of state variables and accounts for two deformation-rate mechanisms: (i) transient flow associated with generally reversible isotropic and kinematic hardening, and (ii) steady-state flow, associated with irreversible viscous deformation.

TL;DR: In this paper, the authors used the computer-controlled "ramped-freezing" mode associated with the X-ray photography technique developed at the National Research Council of Canada by Penner was used to study the variation of the maximum and minimum temperatures at the face of a growing ice lens during transient freezing in two different clayey silts.

TL;DR: In this article, combined measurements of soil temperature and electric potential in the upper 15 cm of a glacial sandy-loam soil were made during the winters of 1986-1987 and 1987-1988 at the University of Michigan Botanical Gardens at frequencies varying from 10 min to daily (midnight).

TL;DR: In this paper, a series of 42 fracture toughness tests were performed on laboratory-grown S2 columnar freshwater ice at high homologous temperatures (−2 to 0° C) to obtain an apparent fracture toughness, an effective elastic modulus, a lower bound estimate of the crack speed, and a sideloaded flexural strength of the ice.

TL;DR: In this article, a multiaxial differential model is proposed for pure flow in orthotropic polycrystalline ice, where the derivation of the constitutive equations is based on thermodynamics with internal-state variables.

TL;DR: In this paper, a previously developed thermodynamic ice growth model is used to predict temporal changes in the physical properties of the ice sheet relevant to breakup, allowing the susceptibility of ice to different destructive processes to be assessed on a seasonal basis.

TL;DR: In this article, an in-situ measurement technique was used to characterize the macroscopic optical properties of sea ice using an artificial light source and measuring the transmitted intensity with a light detector held under the ice.

TL;DR: In this paper, the water content as a function of temperature was measured in the laboratory using pulsed nuclear magnetic resonance (PNMR) for sixteen undisturbed frozen cores acquired from the Northwest Alaska Pipeline Company Chilled Gas Test Facility.

TL;DR: In this article, the bending strength of alluvium-reinforced ice has been investigated and it is shown that bending strength tends to increase with decreasing particle size, and also suggest that there is a critical percentage reinforcement, above which value considerably higher bending strengths are obtained.

TL;DR: In this paper, the authors present results of small-beam testing conducted in a test tank on ice corresponding in structure to the two major ice types encountered in lake ice-sheets.

TL;DR: In this article, a model for thermal growth of border ice in rivers is presented, which takes into account heat loss to the atmosphere, water temperature and local velocity and turbulence level of the river.

TL;DR: In this paper, improvements are developed to the concept of frost-susceptibility testing in order to reflect complex frost-heaving mechanisms of soils, specifically for road construction applications.

TL;DR: In this paper, the authors suggest that a strong crystallographic and growth alignment commonly observed in sea ice may form by the interaction of laminar fluid flow with the base of the growing ice cover.

TL;DR: The susceptibility of three highly aggregated, texturally contrasting, agricultural soils (in north-central Italy) to frost action and the role of organic matter in moderating the adverse effect of cyclic freezing and thawing on soil aggregate stability were investigated in this paper.

TL;DR: In order to increase water storage for hydroelectric purposes, a dam is being constructed across the outlet of Austdalsvatnet, the lake in which the glacierAustdalsbreen presently terminates as mentioned in this paper.

TL;DR: One dimensional freezing tests with fixed temperature boundary conditions and an applied back-pressure to the pore water were carried out on Devon silt in order to determine pore pressure at an ice lens.

TL;DR: In this article, accurate field data (pressures) and theoretical analysis of the problem using a linear creep law to define snow deformation are presented and it is demonstrated that the resulting linear theory underestimates the mean pressures by about 20%. Higher accuracy will require a nonlinear deformation law.

TL;DR: In this paper, Spectral analysis was applied to 940 kilometers of under-ice thickness data in the Canada Basin as recorded by the USS Queenfish, August 1970, and the spacing distributions of independent keels were compared to the theoretical negative exponential and lognormal distributions and were found to be significantly different from the expected frequencies of the negative exponential model, but generally agreed with the Lognormal model except for deep-draft keels.

TL;DR: In this paper, the authors have shown that the pressure field around a pressure meter is much more complex than the uniform stresses that exist in a compression specimen, and in the early stages of the pressure meter test, the stress field changes with time even though the pressure in the pressuremeter is held constant.

TL;DR: In this article, the authors conducted a survey of the borehole at Byrd Station, Antarctica and found that there has been little deformation in the Holocene ice comprising the upper 1000 m at the station and what deformation is occurring in the Wisconsin ice beginning at 1200 m depth.

TL;DR: In this paper, the results of constant load unconfined compression tests undertaken by Mellor and Cole are analyzed, assuming that, during the primary creep phase, ice behaves according to a power law.