Large scale resource development, inevitably, is affected by the impacts of governmental activities related to environmental laws, government rules, or public ownership of lands or resources required for the proposed development. The elected heads of large government entities generally support new, resource related development. However, a government’s agencies may move slowly, and, in an uncoordinated manner, impose conflicting requirements on the potential developer while, perhaps, not placing the specific development project toward the top of their priorities for timely consideration.

Interprovincial Pipe Line (NW) Ltd. is building a buried oil pipeline from Norman Wells in the Northwest Territories to Zama in Alberta. Construction of the pipeline will take place during 1983, 1984 and 1985. Mainline construction will take place during the winter months, with the first work commencing in December 1983.

Load capacity of friction piles embedded in frozen ground is dependent on the long-term adfreeze bond strength at the pile/frozen soil interface. This bond strength is dependent on several factors including type and roughness of the pile, loading geometry, soil type, temperature, ice and mineral volume fractions, and the presence of any impurities in the ice matrix. Three components of bond strength observed in tests included ice adhesion, friction, and mechanical interaction forces involving pile surface roughness. Experimental work showed that ice adhesion was mobilized at very small displacements and that failure (start of tertiary creep) developed before full mobilization of mechanical interaction forces. An increase in surface roughness (addition of lugs to the model pile) along with larger displacement greatly increased the adfreeze bond strength and load capacity. A summary of the creep data (load versus time for a given displacement) illustrated agreement between the measured load capacity and a curve based on Vyalov’s long term strength equation. A new method for prediction of load capacity is suggested based on Vyalov’s equation using parameters from tests on representative frozen soils at temperatures and loading conditions corresponding to the field situation.

An alternating stress as small as 5% of the static stress was found to accelerate the displacement rates of piles subjected to long-term loads in frozen soils, as well as the creep rate of frozen soil samples subjected to uniaxial loading under compression. This effect essentially reduces the bearing capacity of piles in frozen soils, and has to be taken into consideration in the design of foundations in permafrost areas.

Evolution of the creep theory for piles in ice or ice-rich material has provided a vital tool for designing piles to meet imposed long-term settlement limits. However, work published to date has not focussed on the process of selecting an appropriate ground temperature(s) for long-term pile performance nor on the effects of pile creep rate variations due to annual temperature cycles.

A methodology was developed for determination of design hydrographs for planning of facilities in flood hazard areas of ungauged streams draining glaciers. For the same area and rainfall, glaciated stream basins have significantly longer duration and lower peak flows than non-glaciated streams. Both peak and duration of flow for design events must have reasonable accuracy to design dam spillways and to predict scour attack on banks, levees, bridge abutments, and buried pipelines. Although some regression techniques are available for estimating peak flows, they do not provide estimates of flow duration. The regression methods are also unreliable since they were derived using short records from stream basins with large differences in glacier area, elevation, and precipitation. A hydrograph synthesis model was developed to permit more reliable hydrologic estimates of flows. Application of the model was restricted to stream basins in south and southeast Alaska with significant glacier area and no potential for jokulhlaups. Meteorologic, hydrologic, and glacier data were available for flood events in Wolverine, Gulkana, Nuka, Lemon Creek, Herbert, and Mendenhall Glacier basins. The U.S. Army Corps of Engineers HEC-1 model was calibrated to observed flood events by varying precipitation, snowmelt, and routing parameters within reasonable limits. The calibrated models were then verified by synthesizing flood events not used in the calibration process. A procedure was presented for determining design flood hydrographs for ungauged glaciated streams. Recommended precipitation, air temperature, and wind speed relationships with elevation were provided. Antecedent conditions, firn routing, englacial routing and synthetic unit hydrograph parameters were given as a function of glacier zones.

In cold regions ice-related floods can make a significant, and often dominant, contribution to the flood population. They should therefore be considered in a flood frequency analysis. However, in many instances, historical data for this purpose is lacking. Resort must then be made to analytical estimates of ice-related flood stages. This paper describes the determination and application of such estimates for a site on the Missisquoi River near Richford, Vermont.

Experimental ditching tests were conducted with the Banister 710 Arctic wheel ditcher at seven sites judged to be representative of terrain conditions along a proposed pipeline route on Melville Island. Data obtained from the test program included machine performance with various types of experimental teeth, observation of frozen soil exposed in the excavation, characteristics of the spoil pile, and behaviour of the backfilled ditches after two thaw seasons. This paper concentrates on the geotechnical factors that affect ditchability of high arctic permafrost soils and the behaviour of ice-rich spoil when it is used as backfill over a pipeline. The most significant factor affecting ditcher progress was the extent and distribution of ground ice in the soils. The effects of ground temperature were evaluated by conducting portions of the program in the fall and spring. Soil temperatures were approximately 15°C colder in the spring, resulting in a 50 percent decrease in ditching rate. Backfill performance observations have been compared with those from a previous test where excavation was accomplished using explosives and backhoe. Substantially improved backfill performance was observed with ditcher excavated soil because of more uniform gradation of the frozen chunks and the smooth, non-fractured nature of the ditch walls.

The North Slope Borough is current designing and constructing an underground utilities system to provide sewage and water services throughout the Barrow community. The system’s main design element is a buried utility corridor sized for man access, heated with circulating water, and located in permafrost with high ice content. The aggregates available and environmental conditions in Barrow have produced unique design considerations for utilidor construction. In order to achieve a stable thermal state and protect the structural integrity of the utilidor, it was necessary to develop unique construction techniques for backfilling of the system.

Recent advances in the creep analysis for vertical and laterally loaded piles in permafrost, together with data on the creep of saline fine-grained soils allow the presentation of some preliminary design charts for piles in saline permafrost. The effects of salinity, rate of loading and ground temperature are discussed, and incorporated as far as possible in the analysis.

Procedures for designing single pile supports to meet the intent of governing codes must consider the buckling as well as the bending and axial behaviour of the pile. Analysis of the buckling of a cantilever pile partially embedded in frozen soil is facilitated if an equivalent buckling length can be assessed.

This paper presents the results of observations made during the first phase of operation of a large-scale model of a chilled pipeline, buried in two different types of soils. This task was a part of a joint France-Canada project to study freezing around a refrigerated pipeline in a controlled environment facility in Caen, France. In the test facility, a 273 mm in diameter and 18 m long pipe was buried at a depth of 30 cm in an 18 m long x 8 m wide x 2 m deep pit. Along the length of the pipe, half of the pit contained a slightly frost susceptible sand and half a very frost susceptible silty soil. The pipe was refrigerated to -2°C, and the ambient chamber temperature was held slightly below zero. The pipe and the two soils were heavily instrumented to monitor thermal and moisture regime, ground heave, and pipe deformations and displacements.

An important element of the ice management in northern rivers is forecasting water temperatures to predict the time of ice formation. The freeze-up forecast provides needed information for planning flow regulations and scheduling of the close of a navigation season. In this paper, the relationship between variations of air temperature and water temperature is analyzed. An analytical expression for water temperature is obtained through the solution of a simplified convection-diffusion equation. The air temperature is represented as a combination of a harmonic function and short term fluctuations. The short term fluctuations are determined from National Weather Services forecasts.

Thermal discharge, when released into an ice-covered river or cooling pond, causes an area of open-water that is dependent on climatic factors and the heat input. This open-water is a major source of water vapour transfer to the atmosphere for the formation of ice fog in cold regions. A heat transfer coefficient (which characterizes the rate of heat loss from the water surface based on the temperature differential between water and air) is a significant factor in determining the area of the open-water surface. This coefficient is a function of radiative, conductive and evaporative heat loss, which are in turn functions of air and water temperature, wind speed and humidity.

This paper presents the planning, construction and post-construction monitoring of an airstrip located in a remote area of northwest Alaska approximately 100 miles north of Kotzebue and approximately 60 miles inland of the coast. After construction was completed, thermistor strings were installed at several locations along the air strip to monitor short and long term effects of the air strip on the subsurface thermal regime. A two year data base has generally confirmed predicted performance.

In an effort to stop the thermal degradation of permafrost in a 60 metre (200’) portion of the paved Bethel Runway 18-36, a system of two (2) phase (liquid-gas) heat transfer devices (thermoprobes) were installed during the winter of 1982.

An attempt to stabilize differential settlement in the pile foundation of the Central Gas Injection Facilities at Prudhoe Bay, Alaska resulted in a comprehensive subgrade thermal monitoring program to be undertaken in July 1981. The subgrade below the elevated, pile-supported modules was insulated and selected piling were converted to two-phase thermosyphons in an attempt to reduce subgrade temperatures in order to control pile settlement. Monthly temperature data are available since 1982 and biweekly data are available for 1981. Spatial distribution of data collection points provides near-surface data just below the insulation and data at depths to 9 m (30 ft) in locations with various surface conditions. Observations are summarized on the change in the subgrade thermal regime due to the effects of insulation, thermosyphons, and ambient conditions.

Recent studies for hydropower development in northern Canada have given much attention to the potential effects of flow regulation on the winter regime of rivers, including levels and thicknesses of ice accumulations during freeze-up and break-up. Generally, increased flows during freeze-up result in higher, thicker ice covers in early winter. Fluctuating flows may detrimentally affect the stability of ice covers, particularly in the period just after freeze-up.

Phase change produces some of the most dramatic volume and strength change effects on soils in cold regions. Numerical solution techniques provide powerful tools for analysis of real-world heat flow problems. In our engineering practice, we have found a two-dimensional finite-element computer program called "DOT" (Determination of Temperature) to be particularly useful. Capabilities of the program include an ability to handle transient as well as steady-state problems, arbitrary geometries, inhomogeneous materials and non-uniform initial temperature distributions. Example applications of the DOT program described in the paper include calculation of thawing around a warm pipeline in permafrost, thawing around warm oil wells in permafrost (including the influence of a convection surface), and frost penetration as a result of placement of gravel fill in shallow seawater on the arctic coast. Limited data are presented comparing predicted and measured thaw for one of the examples.

Major design problems for seawater intakes on the Alaska Beaufort Sea coast include the need to deal with ice formation and ice forces for 8-9 months of the year. Intakes to be placed in shallow coastal waters must also be designed to resist effects of storm surge, wave forces, and sedimentation. These conditions combine to pose a high risk of entrapping fish and marine mammals that enter the intake area or the intake itself. Because these creatures (especially anadromous fish) form much of the subsistence base of native peoples of the Arctic, they are of prime importance as natural resources. Thus, the intake facility must be designed to exert minimal impact upon those organisms, while also providing a water supply of specified quality and reliability.

The public health of Greenland population has improved considerably during the past 30 years. The main reason is the effective combating of the diseases and the change of the physical surroundings first of all of the housing. But it is difficult to distinguish the importance of development of housing from other reasons.

Pangnirtung is a community of almost 1,000 persons situated close to the Arctic Circle on Baffin Island. Water is obtained from a nearby stream during the warmer months and from an existing storage reservoir during the winter. Lack of capacity and operational problems with the existing reservoir have dictated the need for major improvements to the water supply system. This paper describes the existing situation and the evaluation of alternatives that was carried out to arrive at the most cost-effective solution to the upgrading and expansion of the water supply system.

Earthworks water reservoirs have been constructed by the Government of the Northwest Territories in eight communities to date, and it is anticipated that similar reservoirs will be constructed in a number of other northern communities in the future.

More than ten gravel islands have been constructed for use as exploratory drilling platforms in the Alaskan Beaufort Sea during the last five years In U.S. federal waters, the Minerals Management Service of the Department of Interior requires platform verification for all islands. Verification consists of two phases: first, adequacy of the design is evaluated and, second, construction of the island is monitored to ensure construction in accordance with its design. Described herein are observations, measurements, and instrumentation used to monitor the construction and performance of these offshore platforms. Design concerns are reviewed, including foundation stability, island stability and the environmental forces which could affect island integrity. The role of different construction alternatives is also considered with focus on uncertainties resulting from either summer or winter construction. Procedures are also recommended for monitoring the construction of gravel islands.

This paper reports aerial photo observations on five large rockslides in the Canadian Arctic Archipelago. Four large rockslides, involving Proterozoic gneisses, and which vary in volume between 5 x 10⁶ m³ and 40 x 10⁶ m³, are described from fiord slopes in the Hall Peninsula, Baffin Island. The rockslide at Cape Hotham, Cornwallis Island, which involves Paleozoic carbonates, is also discussed.

Geotechnical problems have posed frequent challenges for highway designers and builders in Alaska. The Glenn Highway, west of Glennallen, passes through an area of discontinuous permafrost consisting of glacial till overlying a heavily sheared and fractured claystone (Matanuska Formation). In 1972, a project was undertaken to straighten a 2 km section of the highway at the crossing of the Little Nelchina River (Milepost 137). The realignment involved construction of sidehill and through cuts in conjunction with embankment fills approaching a new bridge. Excavation from the cuts and embankment materials consisted of claystone on the east side of the bridge and frozen silty glacial till on the west side.

In parts of Alaska where water supply is limited and permafrost exits, heating and circulating water in insulated distribution piping is commonly practiced to prevent freezing. The successful design of a cost-effective recirculating water distribution system depends on providing adequate pipe insulation and on minimizing pumping costs.

During the past three years, the North Slope Borough has been designing and constructing an underground utilities system which will provide sewer and water services for the City of Barrow Alaska. The portions of the utilities system which are subject to the greatest variety of loading conditions are the service connections to the individual buildings. This paper deals with the design and construction of the service laterals which run from the mainlines to the building being served. A typical service connection consists of a gravity sewer line and circulating water lines contained in an insulated conduit ("utiliduct") with insulated boxes, accessible from the surface, installed whenever fittings are required. The transition from the below ground utiliducts to the building connection point is made with a steel structure which has been designed to resist frost jacking and thermal expansion/contraction forces. The paper covers the theoretical design of the piping systems, restraints, utiliducts, insulated boxes and backfill materials, as well as descriptions of the construction process with emphasis on the problems encountered during construction and their solutions.

This paper will summarize procedures and techniques for providing a water supply and for safe wastewater disposal at stations and camps on permanent snow fields. These range from temporary and transient field operations to large scale, permanently occupied facilities.

Icebergs pose a major threat to offshore oil production in the Hibernia field. Bergy bits (visualized as the size of a small cottage) may drift or be propelled by waves into an exploratory drilling vessel. Bergy bits are especially troublesome because they may not be detected during storm conditions yet they could inflict considerable damage to a semi-submersible.

The paper presents an analytical procedure for computing the forces exerted on a gravity platform by the central/non-central impact of a large iceberg. The mathematical modelling of the impact incorporates a seventh boundary degree-of-freedom (at the impact interface) in the equation of motion of the floating iceberg. Both linear/non-linear behaviour is modelled for the seventh degree-of-freedom. Numerical results are given for central/non-central impacts of two sizes of icebergs, one a 5,000,000 t and the other a 12,000,000 t mass iceberg, drifting with velocities of 1.0 and 0.5 m/s. The maximum impact force exerted is about 6.0% of the weight of the iceberg. Non-central impacts cause larger impact forces.

Icebergs originate in the West Greenland glaciers and drift down the coast of Labrador. In their transit, they cross major shipping lanes as well as numerous offshore drilling sites, thereby posing a constant and unpredictable threat to ships, bottom installations and undersea cables.

This paper is concerned with the role of mechanical stabilization in controlling frost susceptibility. This has been assessed in terms of the heave, developed over a 250 hour period, of cylindrical specimens subjected to the Transport and Road Research Laboratory frost heave test. The basic soil matrix consisted of a highly susceptible mixture of sand and ground chalk. Three types of coarse particle - slag, basalt, limestone - were used as the stabilizing agent, and these were each subdivided into two particle groups - 20 to 3.35 mm and 37.5 to 20 mm.

The beneficial effects of geotextiles used to reinforce roads over soft subgrades have been well documented. A theoretical model is presented which demonstrates that currently available and economical geotextiles are capable of supporting roads of about one metre thick over voids in excess of two metres wide. There are many unanswered questions that must be resolved before the concept becomes routinely used. Full scale field tests are underway to help evaluate the most critical unknowns.

Plain and reinforced frozen sand beams were loaded incrementally in pure bending at -6°C and -10°C. For plain beams, the deflection rate (during secondary creep) showed a linear relationship with applied load on a log-log scale while experimental results of beams reinforced with a single 4.76 mm diameter steel bar showed a bilinear relationship. The observed deflection behaviour was a result of the combined effects of creep in tension, compression, and adfreeze bond.

The increased use of pre-insulated polyethylene piping systems as a solution for Arctic piping systems has created the need for more detailed design for specific project applications. Especially in permafrost environments or other areas where high water tables may be expected. Since the insulation is used as a protection mechanism to ensure against pipeline freezing or permafrost degradation, waterproof protection of the insulation and components is vital to overall system performance.

This paper reviews briefly temperature effects on aerobic and anaerobic biological processes relevant to onsite systems. It presents a summary of earlier studies related to temperature conditions in septic tanks and related systems. Summary temperature and performance data on a septic tank and tile field system, near Ottawa are presented in this paper with an analysis of the influence of temperature.

Swedish sewage treatment plant history shows a development towards compact plants. For smaller communities with big changes in flow and temperature, the compact plants offer several problems. Yearly studies of chemical precipitation in stabilization ponds have demonstrated an overall reduction of organic matter (as COD) with about 75% to a level of somewhat below 100 mg O₂/l, and a reduction of total phosphorous with 90% to a level of about 0.7 mg P/l. These values were reached under ordinary operation of the plants and no optimization efforts have been made. All wastewater have been treated (no overflows).

The results of a study into the influence of confining pressure and salinity on the strength of frozen sand confirm a dramatic drop in the strength of frozen sand with increasing soil salinity. The angle of shearing resistance is independent of soil salinity between 0.2 and 0.8%, while the cohesion is linearly dependent on the salinity. The study indicate, that, in the long-term frozen saline sand at a temperature of -7°C may not achieve much strength increase when the soil salinity is higher than 0.2%.

The strength of frozen soils is strongly dependent upon the ice content of the soil. In saline soils, the volumetric ice content is governed by the initial pore-fluid salinity for a specific temperature. In addition to the volumetric ice content, the distribution of the ice in the pores, and its temperature, play a critical role in defining the strength of the frozen materials.

A laboratory testing facility has been established in which sand samples with gas hydrates can be prepared and the mechanical behaviour of the samples studied. The samples have been prepared using Freon 12 as the hydrate former. The testing was conducted in a modified triaxial cell in which the load platens had been modified to contain sonic transducers. This allowed P wave velocities to be monitored before triaxial compression testing. The velocities were measured over a range of temperatures. Little temperature dependence of the P wave velocity was observed below 0°C, while, above 0°C the P wave velocity decreased significantly due to the presence of unfrozen water. The triaxial compressional test data indicates that, with proper sample preparation and testing technique, the hydrate bonded sand behaved in a manner similar to ice bonded sand.

Snow access roads and work pads will be required on Melville Island in the high Arctic to support construction of a natural gas pipeline for the Arctic Pilot Project. Both structures are essential to protect the terrain from scuffing and wear that could lead to slumping and erosion on a scale large enough to threaten the integrity of the pipeline.

In recognition of the need to better define the potential to use cement for stabilization of roadway materials in cold regions a laboratory and field program was conducted. Specifically, the cement requirements to stabilize roadway materials from Barrow, Alaska, were investigated in the laboratory at molding and curing temperatures of 0 to 20°C (32 and 68°F). Both Type I (general purpose or normal) and Type III (high early strength) cements were employed in the program. The laboratory test results indicate that the cement requirements for the material were for all practical purposes independent of the molding and curing temperature and cement type. Following the laboratory program, a 30 x 7 m (100 x 24 ft.) cement stabilized Field Test Section was constructed in Barrow, Alaska, September 1982. The wind velocity on the day of construction was 32 km/hr (20 mph) and the temperature was 0°C (32°F). The compacted mixture was covered with insulating blankets and allowed to cure for seven days after which time the blankets were removed. In June 1983, the Field Test Section was evaluated by measuring Benkelman Beam deflections under the design loading condition (a fully loaded "DJB" dump truck). The deflections measured indicated the roadway materials, cured over the winter months, were performing satisfactorily. A condition survey of the Field Test Section was conducted in October 1983, after traffic had been allowed on the Test Section for over one year. The survey indicated the Test Section was performing well with the only failures at the extreme edges of the shoulder.

Numerous airports have been built within the past 30 years or so in the area under jurisdiction of the Western Region of Transport Canada. Many of these have asphalt pavement surfaces that have had or will require rehabilitation due primarily to roughness developed under the severe climatic conditions experienced in these regions. A description of pavement condition evaluation techniques used to establish the need for rehabilitation and construction history records on some projects is presented.

A pilot scale study was undertaken in Whitehorse, Yukon to investigate the treatability of dilute, cold wastewater with a rotating biological contactor (RBC). Dilute wastewater is generated at a number of northern communities because of water bleeding practices which are often required for utility system freeze prevention.

During the past several years, with increased activity in Arctic regions, a growing need has developed for the efficient treatment of waste streams from relocatable camps in these areas.

The rotating biological contactor (RBC) is a relatively simple and reliable means of providing good to high quality secondary wastewater treatment. This paper investigates the effect of low temperatures (<10°C) on RBC treatment efficiency.

While it is agreed that decreasing temperatures will decrease treatment efficiency, the exact nature of this decrease is not conclusive. RBC manufacturers use empirically developed temperature correction factors, a ‘ s, to significantly increase the RBC media area for low temperature (5°C to 13°C) applications. Use of the well known Van’t Hoff-Arrhenius and Streeter-Phelps models (which use a temperature activity coefficient, q) have been reported, but both the nature of the theory and the q ’s reported in the literature lead to a questioning of the validity of these models. At least one group of authors, Wu et al (1983), have developed empirical RBC efficiency models which are a function of loading, number of stages and temperature.

In an attempt to clarify this situation, 3 stage, 6.75 m², bench scale RBC units were operated under three steady-state flow conditions, treating a moderately high strength wastewater (BOD₅ @ 400 mg/L) at nominal liquid temperatures of 15°C, 10°C, 5°C and 1°C. Results indicate that the effect of temperature on RBC treatment efficiency increases with decreasing temperature and that using the Streeter-Phelps model with a single, constant q is not valid. As an alternative, an empirical model of the effect of temperature was developed from the experimental data. For comparison purposes q’s were also calculated and reported for narrow 4°C to 5°C bands over the 1°C to 15°C range. Given proper loadings, RBC’s are shown to be capable of achieving good (>80%) removals even at extremely low temperatures (<5°C).

In preparation for various types of construction, mining, or farming activities in permafrost terrain, some initial thawing and consolidation of near-surface permafrost soils may be beneficial. Current scientific data indicate that a major climatic warming trend is now commencing as a result of man-induced increases in atmospheric carbon dioxide. Engineers should be aware that the future presence and thermal stability of permafrost cannot be assured, and thawing in advance of construction may be the best long-range alternative. Various components of the surface energy balance are analyzed to determine how to increase the solar heat gain of a soil surface during thawing periods. Six field test plots were constructed in 1980 with different combinations of vegetation stripping, gravel pad placement, surface darkening with asphalt, and clear polyethylene film coverings, to intensify the thawing of permafrost silt soils. Results of four years of observations on these plots are presented and discussed. By stripping the vegetation, an increase of 2.0 m in thaw depth was reached after 4 years. The addition of an asphalt coated gravel pad covered by a clear polyethylene film to create a greenhouse effect, resulted in an increase to 3.0 m in the 4 year thaw depth. The benefits, and drawbacks are discussed for each surface modification, and possible improvements are suggested.

A methodology for the analysis of uncertainties and their incorporation in the prediction of the normalized dimensionless pore-pressure ratio V(z, t) for thaw-consolidation of frozen soils is presented. The linear-first order approximation of the statistical parameters results in the assessment of explicit reliability of predicting V(z, t) for specified design conditions. The reliability measure is developed as an alternative to the arbitrary safety-factor approach and to facilitate probability based design and analysis with explicit reliability measures.

Using synthetic insulation in roadway embankments is a recent development. In the Arctic it is used to prevent permafrost degradation and settlements. Criteria for choosing an insulation material are thermal properties, limits on moisture absorption and compressive strength at a preset deformation. Field and laboratory experimental results indicate that extruded polystyrene has a combination of properties that makes it more acceptable than other types of insulation. Over the years, extruded polystyrene has become the de facto standard for synthetically insulated roadway embankments.

The Alaska Department of Transportation and Public Facilities, Research Section, has tested several winter maintenance sands to determine which are best suited to reduce skid resistance. It was found that coal ash provided the best skid reduction properties. Concrete sand was superior to the normally used State maintenance sand. Fractured particles proved superior to rounded aggregate.

The economic design of steel caissons, for drilling and production platforms in the Arctic Ocean, formed from steel plates and supported by a rectangular grid of stiffeners, beams and girders, requires that the full strength of the plates be mobilized to withstand extreme ice forces.

Over the past decade, several advances have been made in the field of ice engineering. This paper represents an attempt to incorporate these advances into the ice load provisions contained in CSA Standard S6, Design of Highway Bridges. Suggested revisions to the Standard include modifications to the current formula for evaluating the dynamic ice force for crushing, the addition of a formula for predicting the force on inclined piers and addition of a procedure for reducing the magnitude of ice forces on small streams that cannot carry large ice floes. Specific design recommendations are also suggested for the evaluation of transverse forces, pressures from ice jams and vertical forces from ice adhesion. In addition, comments are made on the application of future research to the Standard.

Many foundation failures have been attributed to the settlement of fill material which was compacted while frozen. Frozen material frequently looks dry and forms what appears to be a dense mass using normal compaction procedures. Upon thawing however, it becomes obvious that the material was not dense and settlements on the order of 5 to 20 percent of the fill height are observed. This paper presents the results of a series of laboratory tests where frozen sandy gravel was compacted in a large mold using several different compaction techniques. The samples were then thawed, saturated, and subjected to dynamic loading, and the settlement was recorded. At compaction water contents of over about 4 percent it was not possible to achieve even minimum density, and at a compaction water content of 2% extreme compactive effort was necessary to obtain a material that would settle less than 2% of its height upon thawing. The inability of a material to be compacted appears to increase with increasing water content, smaller grain size and colder temperature.

A layer of unfrozen water exists between the soil particle surface and the solid ice phase in a frozen soil at temperatures of practical concern. This layer owes its existence to the effect of field forces associated with the soil particle surfaces. Its thickness depends on factors such as temperature, solute concentration and specific surface area. Additional unfrozen water occurs within the polycrystalline pore ice as well.

A two-pronged metal probe has been developed at the Division of Building Research, National Research Council of Canada, to simultaneously measure the thermal conductivity and volumetric water content of soils in the laboratory and in the field. Thermal conductivity is measured by using one prong as a transient line heat source probe. Using both prongs as a parallel transmission line, the apparent dielectric constant of the soil is determined by the time-domain reflectometry technique. Volumetric water content is related to the apparent dielectric constant by an empirical relationship valid for most soils. This paper describes the construction and use of the probe and presents some preliminary results obtained in the laboratory and in the field.

Septage, the waste sludge resulting from septic tanks, has in recent times become a recognized but difficult waste to process. It is estimated that some 20 million septic tanks serve about 80 million people in the United States. A great deal of attention has been devoted to the design, construction and operation of septic tanks themselves and properly so. However, it is equally important to realize that unless the septage is periodically removed from the tank, the system will indeed be doomed to failure. Only during the past decade has septage received the attention it deserves.

Located at 82.3N 62.0W, Canadian Forces Station Alert is the most northern permanent settlement in North America.

A numerical transverse mixing model was applied to study the mixing of the Whitehorse sewage lagoons effluent within the Yukon River.

The largest single building energy load in most northern buildings is heating of ventilating air. Construction of tighter buildings to minimize this load has sometimes resulted in serious indoor air pollution. An adequate means of measuring air exchange rates is needed in order for real progress to be made in this area.

Steady-state and non steady-state finite element analyses of the heat loss occurring from basement and slab-on-grade constructions have been performed. The amount of rigid foam insulation was varied on the perimeter of the walls and slab to determine the effectiveness of various insulation configurations. Annual heat loss per linear foot of wall or slab are reported for both Anchorage and Fairbanks, Alaska weather conditions and soil types using these various insulation configurations.

Northern communities are often faced with difficulties of accessibility by overland transportation. One such isolated community is Fort Chipewyan, Alberta, which is located on the north shore of Lake Athabasca in northeastern Alberta. Vehicular traffic can only reach the town during the winter months, so the residents depend heavily on delivery of supplies by means of a winter road which crosses three ice bridges. Difficulties in completion of one of these ice bridges led to an investigation of alternate routes for the winter road in order to reduce the number of ice crossings to only one and to enable earlier operation of the winter road. The results of this study include an assessment of loading and velocity criteria applied to ice bridges and an analysis of synoptic ice formation patterns on the candidate rivers considered for possible crossings. Field observations of ice formation patterns, water quality assessment and ice bridge loadings are described. Ice generation and formation patterns were found to differ significantly between some of the sites under consideration. The study concluded that relocation of the winter road was not feasible because the single crossing alternative would have to be located on a river which forms an ice cover later than the existing sites and is also subject to formation of open leads.

The long-term bearing capacity of ice fields subjected to static and quasi-static loading conditions is estimated on the basis of the structure-foundation interaction analysis. Two models of the foundation are considered, the Winkler model and the continuous solid medium. The time and temperature-dependent effects are treated using the concept of thermorheologically simple behaviour of linearly viscoelastic materials. The problem is solved by means of a modified version of the quasi-elastic method which reduces the viscoelastic interaction analysis to a sequence of identical elastic problems. Numerical examples provide an illustration of the developed solution technique.

Reactions of a circular load pile in both the streamwise and transverse directions to ice loads on a small stream in Alberta have been recorded. Ice loads were calculated by a dynamic interaction model between ice and load pile.

This paper proposes a comprehensive classification system for peats that will be useful in geotechnical engineering applications. The system is styled similar to the Unified Soil Classification System which has been established primarily for inorganic soils. Examples showing how the system can be used are given.

The north bank of the Ninglick River in western Alaska is eroding at an average rate of 6 to 27 m/yr. The bank erosion is caused by the combined action of heat, waves, and currents. Because of the severity and nature of the erosion problem at Newtok, the protection required is extensive and expensive. By anticipating their problem well in advance, however, the residents of Newtok can approach the solution using less expensive methods designed to slow rather than stop the erosion. Decreasing the rate of erosion may allow the bank to stabilize naturally after several years. Based on preliminary analysis, a series of spur dikes constructed with riprap appears to be the most feasible solution.

In 1969, proposals for pipeline construction from the MacKenzie River delta to northern Alberta, pointed out the need for extensive shallow geotechnical drilling in permafrost. Existing drilling equipment had not addressed the problems related to recovering high quality samples of delicate frozen soils. Consideration for environmental damage combined with the remote nature of the pipeline alignments, required that all activities be carried out with helicopter transportable equipment. The relatively high costs related to helicopter transportation imposed severe constraints on load sizes, quantities and equipment capacities. It became evident that development of a drill dedicated to operating efficiently under these restraints would be in considerable demand.

When discussing extremes in cold region construction, the difference in labour productivity rates versus temperature must certainly be included. Productivities frequently vary significantly within the same seasonal period and must be accounted for as part of the contractor’s bid as a risk factor. That risk may be reduced with better predictability of labour productivity for those workers exposed to the elements.

When an ice cover forms on an open channel, the conventional (open water) stage-discharge relationship is no longer valid. Currently, in the United States, winter flow rates are determined by cutting holes in the ice and making a conventional flow measurement using current meters. Such measurements are made on an average of one per month. Empirical techniques are then applied to provide estimates of the flow rate for periods between successive winter measurements.

The North Slope of Alaska has experienced oil-related development, and general civil and utilities upgrading during the last decade. Granular materials suitable for foundation pads, road subgrades and utility backfills have been sought extensively and found with mixed success. Known data on the occurrence and index properties of granular materials in the western part of the North Slope, south of Barrow, Alaska, are summarized in the paper. The Gubik formation, and specifically its Barrow Unit, are the sources of granular materials in the area. These materials are generally rounded to sub-rounded sands containing some gravel.

Aerial reconnaissance of the ice regime over some 800 km of the Yukon River, from Lake Laberge to the U.S.-Yukon border, was carried out over two years. The paper describes the nature and rate of freeze-up and break-up progression observed in the two years, and the number and distribution of polynas in mid winter. The latter were found to be closely related to the presence of islands. Freeze-up progressed reasonably steadily over the whole reach after initial lodgement occurred some 700 km downstream of Lake Laberge. Break-up had a totally different character in the two halves of the reach: downstream it was rapid and dynamic; upstream it was slow and thermal. It is concluded that field observations are still essential to develop an understanding of the ice regime of a river reach.

The calculation of freezing index values from average monthly temperatures is attractive because it takes much less effort compared to calculating from daily maximum and minimum temperatures. However, there are errors involved in this method. To evaluate the magnitude of these errors, a study was made of the autumn change-over months for 29 successive winters for several weather stations in Michigan. The results indicate that errors as large as 97 degree-days C (175 degree-days F) may occur in the autumn change-over month, and that a trend between magnitude of error and seasonal freezing index is suggested.

As the development of oil and gas production in Arctic regions progresses, numerous facilities were constructed to support exploration and operations. No area in North America exemplifies this more than the Prudhoe Bay area in Alaska. Although virtually all the developments took place in recent years when the techniques of dealing with permafrost have been well established, there have still been recurring problems with thawing of the permafrost and the associated settlement of the structures.

A numerical model has been developed to aid in the thermal analysis of the design of structures in Arctic and sub-arctic regions. The model uses two-dimensional finite elements to simulate heat transfer through a vertical cross-section. A simple and effective technique, similar to that described by Rolph and Bathe (1982), is employed to simulate freezing and thawing. The model has been modified to simulate thermal pile operation in the modelled region. An analysis of mitigative design measures proposed for a building experiencing thaw consolidation has been selected to illustrate the application of the model. Several simulations were conducted: 1) characterize the existing thermal regime beneath the building in the absence of a detailed historical record and soil property data, 2) determine the sensitivity of the thermal regime to various thermal properties of the soil and boundary conditions, and 3) evaluate the effectiveness of a proposed mitigative design.

Municipalities and industrial installations in cold climates often rely on rivers for their source of water. These rivers usually experience ice cover conditions for a significant portion of the year. Each spring ice runs and, occasionally, ice jam conditions occur. These events are potential hazards to any structure that is located in or near the river. Rivers in cold climates require the consideration of these and other ice-related factors in the process of designing an intake.

The effect of thermal erosion on the thawing of ice-rich permafrost soil received considerable attention during both pre-construction and construction of the Trans-Alaska Pipeline System. Potential consequences of thermal erosion, including ground surface subsidence, downslope movement and redeposition of thawed slope material, headward erosion and severe gullying were considered and addressed during both the design and construction phases of the project.

Correlations were made between frost penetration under Michigan highways and the square root of accumulated freezing degree-days. Frost penetration was determined from methylene blue frost tubes which were read several times during the season. The data base includes readings from frost tubes located in the western half of Michigan’s Upper Peninsula, for seven successive winter seasons. The degree-day values corresponding to the frost depths were based on temperature records from sixteen weather stations in or adjacent to the study area. For analysis, the data were grouped according to Unified Soil Classification, pedological classification and AASHTO classification of the subgrade soils.

Tests have been conducted to measure ice forces on model inclined bridge piers. The angle of inclination ranged from 81° to 45° from the downstream horizontal. Other test variables were ice velocity, ice thickness and ice flexural strength. The model piers were also inverted to bend ice downward. The paper describes the measured ice forces and the modes of observed ice failure.