Frost Penetration Research Articles

Performance of concrete sidewalks: field studies

This article examines the different failure modes of concrete sidewalks through an extensive field survey of sidewalk inventories in major cities in the Canadian Prairies. The major form of sidewalk damage is longitudinal cracks. There was no correlation of either the liquid limit or the plastic limit of the soil beneath the sidewalk with the type of sidewalk damage observed in each city. However, the extent of longitudinal sidewalk damage increases when the sidewalks are founded on soils with high plasticity index. Two failure modes (hogging and sagging) are closely examined through the analysis of observed vertical surface movements to explain the occurrence of longitudinal cracks. It is concluded that the rigid body movements (both uniform vertical movement and tilt) are mainly a consequence of frost penetration beneath the sidewalk. Uniform vertical movement is not very sensitive to moisture changes in the soil underneath the sidewalk. The dominant mode of deformation for sidewalks is hogging. The seasonal temperatures have considerable impact on the interaction of the sidewalk with the underlying soil, but an indirect estimate of the flexural strain or differential movement ratio is not sufficient to determine if they are large enough to exceed the tensile strain of concrete.

Frost penetration in soil with an inclusion of sand: dependence on soil moisture content and winter severity

Frost penetration in soil with an inclusion of sand: dependence on soil moisture content and winter severity

Depth of Frost Penetration in Landfill Cover Systems

ABSTRACT Freezing and thawing of fine-grained soils, of the type typically used for containment applications (i.e., landfill liners, slurry walls, waste pile caps, etc.) has been shown to affect the engineering performance of the soils. Previous research investigations have documented the increase in soil hydraulic conductivity, decrease in strength, and modification of soil porosity following frost penetration into clay soils. Most of these investigations have been conducted in the laboratory, using small-scale test cylinders. The investigations of this study are unique in that they were conducted in the laboratory on large-scale specimens. Thermodynamic and hydraulic measurements obtained during the simulation of freeze/thaw cycles allowed the determination of depth of frost penetration, hydraulic conductivity, and leakage performance of the laboratory model of clay cover liners. Key words: Landfill; frost; leakage; cover liners; cracks; freeze/thaw

A Compilation of Radiocarbon Dates from Disko Bugt, Central West Greenland/Meteorological Observations in 1996 at the Arctic Station, Qeqertarsuaq (Godhavn), Central West Greenland/A Discussion on Pingos in Mellemfjord, Disko, Central West Greenland/Open System Pingos in Mellemfjord, Disko, Central West Greenland: A Reply to Gurney and Worsley

188 new and previously published radiocarbon dates on Holocene material from Disko Bugt, central West Greenland, are presented together with relevant informations (laboratory number, place name, dated material, geografic coordinates, altitude and δ13C-value) about the dates. In October 1990 an automatic weather station was established at the Arctic station (65 °15′N,53 °31′W), Qeqertarsuaq (Godhavn), Central West Greenland. The Station register parameters each 20 min., and the parameters have been described in an earlier paper in this journal by Nielsen et al. (1995). The present paper summarises main points of the climate during 1996. Open system, or more correctly, hydraulic pingos, are genetically poorly understood. A continuing problem concerns their need for a perennial groundwater supply (intra- or sub-permafrost). This has to be maintained despite the existence of continuous permafrost in many areas where they are located. Recent work on Disko Island has suggested a new type of hydraulic pingo developing only in a “marsh environment”. It is argued that the marsh setting is not relevant to the formation of these features and that they are simply hydraulic pingos. A group of marsh initiated open system pingo remnants from the Iterdlagssûp kûgssua valley mouth, in Mellemfjord, Disko Island, Central West Greenland was described in Christiansen (1995). Gurney and Worsley (1997) state that the location of this group of pingo remnants in the Iterdlagssûp kûgssua valley mouth is of no relevance to their genesis, and that they presumably were the result of an assumed late Holocene sea level regression, causing permafrost to be established in the valley bottom. In this reply the arguments by Gurney and Worsley (1997) on the Iterdlagssûp kûgssua valley pingos are commented, and it is argued by way of sea level information, frost penetration and water supply that the special setting must indeed have caused pingo initiation and growth. Furthermore, the area has experienced a relative sea level rise during the late Holocene.

Moisture migration during freeze and thaw of unsaturated soils: modeling and large scale experiments

A coupled heat flow and moisture flow model (FROSTB) was used to simulate large-scale freeze-thaw experiments to assess its ability to predict soil moisture conditions. The experimental data consist of temperature and soil moisture profiles measured during freeze-thaw cycles in a 1-m layer of frost-susceptible silty sand over roughly 2 m of gravelly sand. Two experimental conditions were modeled: (1) where the soil was fairly wet and the water table was shallow (1 m below surface), and (2) where the soil moisture was lower than specific retention and water table was deep. Overall, the model predicts the frost penetration and heave quite well; however, it tends to overpredict ice formation. The additional ice in the modeled frozen soil then causes a slower thaw. Matching the (total) moisture contents in the drier soils results in underpredicting the heave. The discrepancies stem from the model representation of the physical processes involved in freezing (and frost heave) of unsaturated soil. We propose improvements through using a “pseudo” three-phase flow potential and calculating volumetric segrated ice content starting at 90% of saturation. The effects of changing the constants related to hydrologic properties are also discussed.

Local climates simulated by two generations of Canadian GCM land surface schemes

Abstract The performance of two Canadian land surface schemes of widely differing complexity is compared and contrasted in a pair of year‐long simulations using the GCM developed at Atmospheric Environment Service, Canada. The old land surface model incorporates the force‐restore method for soil temperatures and the bucket approximation for soil moisture; the new model, CLASS (Canadian Land Surface Scheme) features three soil layers, an explicitly modelled snow layer, a thermally separate vegetation canopy, and physically‐based calculations of heat and moisture transfers between all of the land surface components and the atmosphere. It was reported in previous papers that compared with observations, the old scheme tends to generate a climate which is characterized by anomalously high precipitation rates and cold temperatures over land. In this paper, by reference to field measurements and to the energy fluxes and temperatures generated by the two models at local scales, the hypotheses earlier postulated as to the underlying reasons for this are validated. The main factor contributing to the climate anomalies observed with the old scheme is found to be its generation of excessive evaporation rates; this is caused by the fact that the evaporation rate is never directly energy‐limited, the fact that the scaling of the evaporation rale with decreasing soil moisture content underestimates the effect of vegetation stomatal resistance, and the fact that the evaporation rate over bare soil depends not on the surface soil moisture, but on the moisture content of whole modelled soil column. The cold surface temperatures are additionally attributed to systematic errors incurred by the forward‐stepping temperature scheme, and to the fact that soils subjected to subzero temperature forcing in the winter are modelling as freezing completely. Finally, the inability of the old scheme to simulate partially frozen soils means that it proves unable to handle either shallow frost penetration at temperature latitudes, or the development of an active layer in permafrost.

Soil moisture variability in relation to diurnal frost heaving on Japanese high mountain slopes

Frost heave, ground temperature and moisture were concurrently monitored on two alpine slopes with thin debris mantles. Electrical sensors connected to data loggers permitted automated monitoring of the three variables. Diurnal frost heave of up to 3 cm frequently took place during spring and autumn. Soil moisture contents are regarded as the primary control on the amount of frost heave, while the intensity of freezing is secondary. Heave was usually greatest just after a major rainstorm that produced high moisture contents in the near-surface soil, and decreased with soil desiccation. Rainstorms often interrupted the desiccation process and reactivated frost heaving. Despite reaching a depth of 1 m or more, seasonal frost penetration caused only small amounts to heave, because the lower part of the seasonally frozen layer was not frost-susceptible. These observations imply that the thin debris mantle and periodic precipitation during periods of freeze-thaw combine to result in the predominance of shallow frost creep, which is typical of soil movements in Japanese high mountains.

MEASUREMENT OF FROST-INDUCED SNOWMELT RUNOFF IN A FOREST SOIL

Snow interception in a coniferous stand leads to considerable short-range variability in snowcover depth, which in turn affects the water and heat regime of the soil. To study the coupling between snow accumulation, frost penetration, and hydrological response, plot-scale experiments were conducted in a subalpine spruce forest. The stony, sandy-loamy Spodosol was highly permeable and had an organic layer of 5-15 cm thickness. Within two plots, one underneath a tree crown and one in a canopy gap, we measured near-surface runoff, soil temperature, and liquid water content. Snow and frost depths varied more in space than between two winter periods at given locations. Frost penetration was greater near the trunk, where a higher portion of snowmelt water drained downslope close to the surface than in the gap due to frost-induced reduction of infiltration. In both years, the spring snowmelt occurred over two distinct periods. During the first snowmelt, the water percolated primarily through the frozen layer and part of it probably refroze within the frozen layer, thereby raising the total water and ice content. During the second event, near-surface runoff was more pronounced.

Efficiency of Geosynthetic Lateral Drainage in Northern Climates

During winter the formation of ice lenses causes frost heave within frost-susceptible materials. The uneven spatial distribution of heave due to heterogeneity results in severe damage to the pavement. Fissures are created, favoring excess infiltration, especially during subsequent springtime thaw. The installation of drainage can be beneficial in reducing the amount of water present in road foundations. Some uncertainty, however, exists about the sources of water feeding the lenses and, therefore, the optimal location of the systems. To assess the efficiencies of deep lateral drainage systems, a full-scale test has been undertaken along an existing road constructed on a glacial till subgrade. Three 150-m-long vertical geocomposite systems were installed at depths ranging between 2 and 3 m. In situ monitoring included piezometers and frost indicators and measurements of flow rates and pavement heave. To obtain a point of comparison, the measurements started 1 year before drain installation. For the period of observation the freezing indexes ranged between 1432°C-day and 1558°C-day, and the maximum frost penetration was 2.5 m. The flow rates varied considerably with the seasons, ranging between 1 ml/sec/linear meter during winter and 10 ml/sec/m during the April thaw. Before drainage the heave values ranged between 50 and 150 mm. After installation they were reduced by a factor ranging between 10 and 50 percent.

The forest modelling series ForM-S: applications to the Solling spruce site

The forest model series ForM-S currently includes four modules addressing (1) water fluxes (ForHyM), (2) soil temperature (ForSTeM), (3) ion fluxes (ForIoM), and (4) primary production and nutrient cycling in upland forest stands (ForSVA). The modules require climate records (air temperature, precipitation volume), total atmospheric ion deposition and descriptive site information as input. The models are designed to capture the dynamics of the simulated processes at monthly (ForHyM, ForSTeM, ForIoM) and annual scales (ForSVA). ForHyM and ForSTeM have been verified across diverse sites in North America. For the Solling dataset, ForHyM closely reproduced hydrologic data (monthly throughfall, forest-floor percolate, soil percolate) without further calibration. With ForSTeM and ForHyM, snowpack water, soil temperatures, and frost penetration were simulated. ForIoM simulations compared favourably with the concentration and flux data for individual ion species (H +, K +, Na +, NH + 4, Cl −, NO − 3, Ca 2+, Mg 2+, SO 2− 4, Al x+ ) in throughfall, forest-floor percolate and soil percolate after calibrating one or two parameters for the forest canopy, the forest floor, the mineral soil. Nutrient losses, nutrient uptake rates, base cation replenishment rates within the soil, and biomass production and accumulation for the main stand compartments (foliage, wood, fine roots, forest floor) were simulated with ForSVA. The resulting calculations about cumulative soil leaching losses for Ca, Mg, K, NH 4-N, NO 3-N, and SO 4-S were in good agreement with observations

Snow‐induced thermal variations around a single conifer tree

AbstractThe influence of trees on the ground thermal regime is important to the overall winter energy exchange in a snow‐covered, forested watershed. In this work, spatial zones around a single conifer tree were defined and examined for their controls on the snow cover, snow‐ground interface temperatures and frozen ground extent. A large white spruce (Picea glauca), approximately 18 m tall with a crown diameter of 7.5 m and located in northern Vermont, was the subject of this study. The tree was instrumented with thermistors to measure the snow‐ground interface temperature between the tree trunk and 6 m from the tree into undisturbed snow. Four distinct zones around the conifer are defined that affect the snow distribution characteristics: adjacent to the trunk; the tree well; the tree crown perimeter; and the unaffected area away from the tree. At the time of peak snow accumulation and during the ablation season, snow depth and density profiles were measured. The area beneath the canopy accumulated 34% of the snow accumulated in the undisturbed zone. By the end of the ablation season, the depth of snow under the canopy had decreased to 18% of the undisturbed snow depth. The tree and branch characteristics of spruce in this temperate climate resulted in a different snow depth profile compared with previous empirical relationships around a single conifer. A new relationship is presented for snow distribution around conifer trees that has the ability to better fit data from a variety of conifer types than previously published relationships. Less snow beneath the canopy led to colder snow‐ground interface temperatures than measured in undisturbed snow. The depth of frozen ground in the different zones was modelled using a simple analytical solution that showed deeper frost penetration in the tree well than beneath the undisturbed snow.

The problem of primary frost heave with frost penetration

AbstractThis paper is concerned with a mathematical model for the phenomenon of primary frost heave with frost penetration, which appears in the freezing process of wet soil. The problem is formulated in the form of a free boundary problem with two free boundaries. It is shown that there exists a unique classical solution for this problem.

An alternative road construction for stormwater management in cold climates

A field study of an infiltration and detention facility in northern Sweden is presented. Streets in a housing area were reconstructed to increase the permeable area. Permeable asphalt was used covering a coarse fill material and swales (ditches) were constructed along both sides of the streets. The project will include studies of the water balance during different seasons, frost heave and frost penetration of the streets and the stormwater quality. Due to the reduced infiltration capacity during snowmelt periods, detailed studies will be performed on components of the facility that are important for the disposal of meltwater. Some initial tests of the infiltration capacity of permeable asphalt in cold temperatures indicated sufficient capacity during snowmelt periods.

On the minimum depth of bridge and culvert foundations in seasonal frost regions

Based on extensive field experiments related to frost heave susceptibility of clayey soil and fine sand and frost heave of different depths of foundations, those factors influencing depths of bridge and culvert foundations in seasonal frost regions were analysed in detail. These factors include the correction coefficient to standard frost penetration, the allowable thickness of frozen soil under foundations, the influence coefficient of frost penetration due to the depth of foundations, and so forth. A method and its related parameters for determining the minimum depth of bridge and culvert foundations are presented.

Winter Effects on Hydraulic Conductivity of Compacted Clay

A field test was conducted to determine if freeze-thaw cycles cause increases in hydraulic conductivity in the field, as has been observed in laboratory tests. A test pad of compacted clay was instrumented for monitoring temperatures and climatic conditions and partially insulated. The measurements indicated that up to 10 cycles of freeze-thaw occurred in the uninsulated portion of the test pad whereas no freezing occurred in the insulated portion. Hydraulic-conductivity tests were conducted before and after winter to determine if changes in hydraulic conductivity occurred as a result of winter exposure. In situ hydraulic-conductivity tests showed that the overall hydraulic conductivity was similar in the insulated and uninsulated portions of the test pad before and after winter. No change in overall hydraulic conductivity occurred in the uninsulated region because the depth of frost penetration was only 30% of the thickness of the test pad. However, tests on block specimens collected from near-surface soil that underwent freezing and thawing increased in hydraulic conductivity by a factor of 50–300. Similar increases in hydraulic conductivity were measured using laboratory freeze-thaw tests.

An alternative road construction for stormwater management in cold climates

A field study of an infiltration and detention facility in northern Sweden is presented. Streets in a housing area were reconstructed to increase the permeable area. Permeable asphalt was used covering a coarse fill material and swales (ditches) were constructed along both sides of the streets. The project will include studies of the water balance during different seasons, frost heave and frost penetration of the streets and the stormwater quality. Due to the reduced infiltration capacity during snowmelt periods, detailed studies will be performed on components of the facility that are important for the disposal of meltwater. Some initial tests of the infiltration capacity of permeable asphalt to cold temperatures indicated sufficient capacity during snowmelt periods.

Diurnal freeze–thaw depth in rockwalls: Field measurements and theoretical considerations

AbstractRock temperatures were monitored for a year at two alpine rockwalls in the Akaishi Range, Japan, where permafrost is absent. Diurnal frost and thaw penetration depths were evaluated from subsurface isotherms drawn on the basis of the temperature records at 0, 10 and 40 cm depths. The surface of the rockwalls experienced more than 100 diurnal freeze‐thaw cycles, most of which accompanied a frost or thaw penetration shallower than 50 cm, and several long duration cycles with deeper frost or thaw penetration. Theoretical frost and thaw depths were also calculated by incorporating the surface freezing indices into the modified Berggren equation, the results from which were then compared with the actual values. The modified Berggren equation provided values that showed a strong correlation with observed depths, despite somewhat underestimating the actual values. Using the modified Berggren equation, the seasonal frost depth in the observed winter was estimated to be about 4·5 m. The frost and thaw depths are considered to give the maximum estimation of the depth to which frost‐induced cracking can propagate in the bedrock.

Frost protection of buried PVC water mains in western Canada

Although desirable for many reasons, controlled low-strength material – controlled density fill (nonshrinkable fill) has the potential to promote rapid frost penetration within the trench when used as a backfill material in waterworks construction and repair projects. This paper describes results of a two-dimensional finite-element heat-transfer model study carried out to investigate the effectiveness of various insulation systems for frost and frost-heave protection of buried waterlines. Combinations of nonshrinkable fill with horizontal insulation boards, cylindrical pipe insulation, and inverted U-shaped insulations were investigated. It was shown that, while moderate thicknesses of insulation could be found to protect the pipe from freezing, thermal-bridging effects make the location of the maximum frost penetration depth sensitive to details of the insulation geometry. The use of different combinations of insulating backfills was also investigated, and it was shown that a backfill layer of moderate insulating value placed high in the trench may be most advantageous. Key words : frost, frost protection, insulation, waterlines, nonshrinkable fill, numerical analysis.

Periglacial landforms at Giant'S Castle, Natal Drakensberg, South Africa

AbstractActive and inactive periglacial landforms are described for a small, south‐facing mountain catchment at Giant's Castle, 3140–3300 m A.S.L. Natal Drakensberg, South Africa. Micro‐patterned ground is found at the water divide and indicates marginal present‐day frost activity with soil frost penetration to a depth of 0.1–0.2 m. Downslope, thin stone‐banked sheets migrate over larger, inactive, stone‐banked lobe complexes. Block fields, suggested to be of a gelifluction origin, occupy the central part of the valley and gelifluction sheets cover the lower valley slopes. All are inactive. The range of inactive periglacial slope deposits suggests the presence of severe seasonal frost in the past.

Urban Stormwater Infiltration Perspectives

In urban areas there are many problems with water management: combined sewer overflows, peak flows, man-induced droughts, consolidation of the soil, damage from frost penetration, etc. It is preferable to look at all these problems in relation to each other, according the concept of integrated water management. This paper focuses on the possibilities for urban stormwater infiltration. The results of three studies are presented. The first study concerns the flooding of the Shirako River in Tokyo. It is shown that with the help of stormwater infiltration the floods can be reduced remarkably. The second study concerns combined sewer overflows and the discharge from treatment plants for catchments in Denmark and the Netherlands. When looking at the total yearly discharge from the combined sewer and the treatment plant, it is shown that infiltration is more effective than detention. The third study shows the impact of urban stormwater infiltration on the ground water flux in an area in the south of the Netherlands. To relate the different results from the three studies an analogy is introduced with the human body. The combination of problems results in a so-called urban hang-over. It is shown that the positive effects of urban stormwater infiltration within an integrated approach are more significant than looking at all the effects separately.