The role of forced convection in thawing a sloped frozen layer

Joel Steeves, Lee Barbour, Grant Ferguson, Sean Carey

In the proceedings of: GeoRegina 2014: 67th Canadian Geotechnical Conference

Session: Cold Regions Geotechnics

ABSTRACT: The contribution of heat convection by water flowing down-slope in a frozen slope was investigated as a potential failure mode for a proposed mine waste cover system design. Numerical models of two slopes within the Wolf Creek basin, Yukon, were simulated and thermal Peclet numbers were determined for a variety of water fluxes. The thermal Peclet number is the ratio between convection and conduction and can be used to determine the relative importance of convection. The calculated Peclet numbers reveal that horizontal convection within a surficial, high hydraulic conductivity layer, such as an organic layer, can result in sufficient water flow to initiate convective heat transfer. In the case of a lower hydraulic conductivity mineral soil, convection can likely be neglected. Under realistic snowmelt conditions, conduction dominates in both soils. R…SUM… La contribution de chaleur par convection par lÕeau qui coule en pente descendante dans une pente gel”e a ”t” investigu”e comme mode de d”faillance potentiel pour une conception de syst‘me propos” dÕun couvercle de d”chets miniers. Des mod‘les num”riques de deux pentes dans le basin de Wolf Creek, Yukon, ont ”t” simul”s et des nombres de P”clet thermaux ont ”t” d”termin”s pour une vari”t” de fluxes dÕeau. Le nombre de P”clet thermal est le rapport entre convection et conduction et peut ’tre utilis” pour d”terminer lÕimportance relative de la convection. Les nombres de P”clet calcul”s r”v‘lent que la convection horizontale dans une couche superficielle de haute conductivit” hydraulique, comme une couche organique, peut r”sult” en un montant suffisant dÕ”coulement dÕeau et de transfert de chaleur par convection. Dans le cas de sol min”ral ‹ conductivit” hydraulique plus base, cÕest probable que la convection peut ’tre n”glig”e. Sous des conditions de fonte de neiges r”alistes, la conduction domine dans les deux types de sol.

Please include this code when submitting a data update: GEO2014_261

Access this article:
Canadian Geotechnical Society members can access to this article, along with all other Canadian Geotechnical Conference proceedings, in the Member Area. Conference proceedings are also available in many libraries.

Cite this article: