• Moisture-Temperature Realtionships in a Sand Due to Outward, Radial Freezing

      Juel, Erling A. (1989-05)
      A "clean" sand is commonly specified as backfill around the evaporator section of thermosyphons designed to maintain the thermal regime of pernnially, frozen, thaw-unstable soils. A series of laboratory tests were performed to determine the magnitude of moisture migration. The test results indicate the moisture migration can result due to outward radial freezing in a nonfrost susceptible sand possessing a low to moderate degree of saturation. Moisture did not migrate when the sand was saturated prior to freezing. The redistribution of moisture changes the thermal properties of the soil system which effects the maximum radius of freezing by desiccating soil at the outermost radius of influence and increasing the degree of saturation around the evaporator. The desiccated soil region will experience an accelerated rate of thaw due to a lower volumetric latent heat of fusion. In addition, the radius of freezing is reduced as moisture migrates towards the evaporator section. These effects warrant additional considerations that must be addressed when designing refrigerated foundations with thermosyphons.
    • Outreach and Technology Transfer on the Effectiveness of Wildlife Fences and Wildlife Crossing Structures in a Multifunctional Landscape

      Huijser, Marcel P. (2018-04)
      This project undertook outreach and technology transfer tasks on the effectiveness of wildlife fences and wildlife crossing structures in a multifunctional landscape. The tasks accomplished included (1) publication of an article in an international peer-reviewed journal on the effectiveness of wildlife mitigation measures along U.S. Highway 93 North; (2) submitting an abstract to, presenting at, and attending the 2017 International Conference on Ecology and Transportation in Salt Lake City, Utah; and (3) updating the website and outreach material of the People’s Way Partnership (http://www.peopleswaywildlifecrossings.org/).
    • Parks Highway Load Restriction Study Field Data Analysis

      Raad, Luffi (1998-02)
      The loss of pavement strength during spring thaw could result in excessive road damage under applied traffic loads. Damage assessment associated with the critical thaw period is essential to evaluate current load restriction policies. The Alaska Department of Transportation and Public Facilities (AKDOT&PF) proposed a plan which will provide an engineering analysis fo field conditions with 100% loads on the Parks Highway for 1996. The study was jointly conducted by AKDOT&PF, the Alaskan Trucking Association (ATA), and the University of Alaska Fairbanks Institute of Northern Engineering Transportation Research Center (TRC). Extensive field data were collected and analyzed in an effort to monitor pavement damage during the spring of 1996 and determine the loss of pavement strength. The field data included: 1. Truck traffic data using the Chulitna weigh in motion (WIM) station and the scalehouses at Eagle River and Ester. WIM data were obtained for both northbound and southbound traffic from 199301996. Scalehouse data were obtained for Spring 1996 for comparison with WIM spring data. 2. Pavement temperature data (Spring 1996) for seven ground temperature sites representing typical conditions along the Parks Highway. 3. Profilometer data for pavement roughness and rutting obtained yearly (1993, 1995, and 1996) and also monitored over shorter intervals during Spring 1996. In addition, rut-bar measurements at selected points were also monitored during Spring 1996. 4. Falling Weight Deflectometer (FWD) data for both the northbound and southbound lanes for selected sections in lengths of eight 8 km (5 mile) along the Parks Highway. These data were used in backcalculation of pavement layer moduli, fatigue strength of the asphalt concrete surface, and corresponding damage factors resulting from spring-thaw weakening. Field data were used to analyze the damage effects on the Parks Highways. These included: analysis and comparison of WIM and scalehouse traffic data; determination of overweight axle loads and vehicles; comparison of north- and southbound traffic and its effect on pavement damage; analysis of ground temperature for thaw initiation and propagation; and simulation of the pavement's remaining life, with and without load restrictions, using mechanistic methods. This report presents results of these analyses.
    • Part-Load Economy of Diesel-Electric Generators

      Malosh, James B.; Johnson, Ronald (1985-06)
      Diesel-electric generators used to produce power in rural Alaska are often found to be inefficient and suffer from premature mechanical failures. Such failures are commonly caused by hydrocarbon build-up in the engine resulting from long-term operation under light-load conditions. There are several feasible approaches to this problem which use proven technology. The most technologically direct approach is to properly size systems. Another involves the optimum control of engine oil, coolant and intake air temperature with thermostatically-controlled electric heaters. Economic analysis shows that this approach could save as much as $13,000 per year in the cost of electricity for a 100 kw diesel generator operating at 25% load. However, further research is needed to establish that the mechanical problems associated with part-load operation are actually abated with proper control of operating temperatures. Practical experience implies that this should be the case. Acoustically tuned low restriction intake and exhaust systems are also an attractive approach because they provide a definite increase in efficiency under all operating conditions. However, these units must be developed for a specific engine and operating speed range. They are not presently commercially available, but could be developed in a continuing research effort. Parallel operation of small diesel-electric generators was suggested by many vendors and operators as a method of improving part-load performance. Though it has the benefit of redundant reliability, the economic analysis does not show a clear advantage because of higher electrical costs near full-load conditions. At very low loads, single small units may also suffer from the same mechanical problems as the large units. The other methods of improving part-load performance which include the use of improved injectors and microprocessor-controlled injection pumps are not presently feasible. However, the state of diesel engine technology is changing so rapidly that these items could become feasible in less than two years. These developments should be monitored closely.
    • Passive Solar Alaskan School

      Seifert, Richard D. (1984-12)
    • Passive Solar Heating in Alaska

      Zarling, John (1980-06)
      The relationship between the four elements of passive solar design for small buildings; south facing windows, thermal mass, thermal insulating shutters, and insulation thickness, were studied by computer simulation to determine their long-term effects on energy consumption. Solar and weather data for Fairbanks, Alaska, 65(degrees)N latitude, was the input to the TRNSYS Program used to perform the dynamic simulations. Results for an entire heating season are presented. Overall it is shown that shutters and insulation are the most important elements in the design of energy conserving structures for the north. Thermal mass plays a lesser role, especially during the mid-winter months when direct solar gain is balanced by the building envelope losses.
    • Permafrost Database Development, Characterization, and Mapping for Northern Alaska

      Jorgenson, M. Torre; Kanevskiy, Mikhail; Shur, Yuri; Grunblatt, Jess; Ping, Chien-Lu; Michaelson, Gary (2014-10-31)
    • Phase II: Chulitna River Bridge Structurally Health Monitoring

      Hulsey, J. Leroy; Xiao, Feng; Dolan, J. Daniel (2015-01)
      This study is phase 2 of a two phase research project. In Phase 1 a structural health monitoring system (SHMS) was installed on the Chulitna River Bridge. This bridge is 790 feet long, 42 foot 2 inches wide and has 5 spans. As part of that effort, three loaded dump trucks were used to conduct seventeen static and dynamic loadings on the structure. In addition to studying the bridge using SHMS, two ambient free vibration tests were conducted a year apart by. In 1993, the deck on this 1970 five span bridge was widened from 34-feet to a 42 foot 2 inch concrete deck. Increased load was accounted for by strengthening two variable depth exterior girders and converting interior stringers to interior truss girders. Construction documents for the upgrade called for stage construction. At the time of this study, the bridge had five bearings that were not in contact with the superstructure. Feasibility of using Structural Health Monitoring Systems (SHMS) for Alaska Highway Bridges was examined. Also, SHMS data for the load tests of Phase 1 were used to calibrate a three-dimensional model (FEM) to predict response and conduct a 2014 Operating Load Rating.
    • Pilot Plant Studies and Process Design for the Production of Calcim-Magnesium Acetate

      Ostermann, R.D.; Economides, M.J. (1985-11)
      Chloride salts are commonly used as deicing chemicals in many northern states. These chemicals are corrosive to automobiles, bridge decks and other public structures, and cause considerable damage to plants found near salted roadways. Calcium Magnesium Acetate (CMA) offers potential as an alternate deicing chemical. CMA is a generic term applied to the reaction product of acetic acid and limestone. It is non-corrosive and has no known potential to cause environmental damage. During 1982-194, over 12,000 gallons of saturated CMA solution were produced by researchers in the Petroleum Engineering Department of the University of Alaska - Fairbanks. The raw materials were acetic acid, hydrated lime and native limestone. The product CMA solution was used in road tests in Fairbanks as well as for environmental studies. The results of these pilot plant studies is presented in this report. A process design for the production of 12,000 GPD of CMA from native limestone based on the results of the pilot plant studies is presented. For a grass-roots operation located in Fairbanks, the total capital cost is estimated at $215,000, including site and structure costs. Using current prices for acetic acid, limestone and hydrated lime, a product price of $413 per ton (dry CMA equivalent) is required for a 15% annual rate of return. It should be noted that raw materials costs amount to over 85% of the annual operating costs with capital cost amortization amounting to only 2% of the product cost. The process economics are thus relatively insensitive to changes in capital costs due to process design changes. Moreover, acetic acid cost alone accounts for 70% of the product price. The key to reducing the price of CMA lies in obtaining inexpensive acetic acid.
    • Preliminary Design and Feasibility Study for a Calcium-Magnesium Acetate Unit

      Economides, M. J.; Ostermann, R. D. (1982-07)
      The adverse environmental effects and corrosion problems associated with the use of chloride salts as de-icing agents have prompted a search for alternative de-icing compounds. Calcium and Magnesium Acetates (CMA) exhibit excellent de-icing characteristics yet are not corrosive or harmful to the environment. A viable process design for the production of CMA has been developed based on the results of a series of kinetic reaction experiments conducted at the University of Alaska. Acetic acid and native Alaskan limestones were used as the raw materials. An economic evaluation of the process indicates a selling price of less than $600/ton of solid CMA, based on teh production of a saturated, aqueous CMA solution in small scale facilities (10,000 - 50,000 gallons/day). At the upper range of production rates studied (50,000 GPD) and for an acetic acid cost of $1.25/gallon, the calculated CMA price was $290/ton of solid. This represents a minimum price and is attractive when compared with the cost of other de-icing compounds. The results of this cooperative project between the Petroleum Engineering Department at the University of Alaska, Fairbanks and the State D.O.T. are highly encouraging. With the use of native Alaskan limestone and acetic acid, the process economics point toward a high quality, competitively priced product. The environmental advantages of CMA over Chloride salts and reduced secondary costs due to lower corrosion rates for vehicles and bridges indicate that CMA may become the premier de-icing agent.
    • Preliminary Study on Snowplow Survivability of Guardrail Terminals

      Ma, Zhongguo (John); Mattingly, Steven P. (2000-08-01)
      FHWA has asked Alaska Department of Transportation and Public Facilities (DOT&PF) to fix damaged longitudinal and end sections of guardrail throughout Alaska's road system. The proposed research evaluates W-beam guardrail end terminals (GET) which are installed along roads in heavy-snow areas of Alaska. Primarily, it is important for DOT&PF to determine how well GET withstand loads generated during snow plowing and blowing operations. Based on this preliminary study, the following conclusions are made (1) Anecdotal evidence indicates that the newly installed SRT-350s are not very forgiving (because they are designed to be crash-friendly), and relatively minor contact between the snow removal equipment and the terminal may result in terminal failure and at least some damage. (2) There are two types of damage to the newly installed SRT-350s; (a) damage due to contact between the snow removal equipment and the terminal; and (b) damage resulting from the pressure of the snow (snow-only contact). The first type is the most likely damage observed in field visits. The damage due to snow-only contact can occur in heavy snow area. (3) Except in heavy snow area, the average replacement rate for newly installed SRT-350s can be reduced to about the same level as the traditional BCTs if the snowplow operator learn to respect the new terminals more and provide them with a wide berth. To achieve this, it is very important to mark the end of the terminal as well as the beginning of the flare of the terminal. With both locations marked, an operator can carefully avoid the entire length of the terminal. (4) Further research is needed to investigate guardrail end terminals which are more durable or are easily repaired.
    • Product Evaluation: Presto Roadbase Sand Confinement Grid

      Coetzee, Nicolaas F. (1983-06)
      The Alaska Department of Transportation and Public Facilities is continuously looking for methods of using marginal soils for roadway and airport embankments. In areas such as the Western coast of Alaska, where quality materials must be imported and therefore are prohibitively expensive, the use of native soils represents a significant cost savings to the State. The Army Corps of Engineer Experimental Waterways Station has developed a method of stabilizing sand using a plastic grid system. This report analyzes the system for use in Western Alaska using a finite element analysis and the Chev5L computer program. These analysis indicate that the grid system is at least equal to 6 inches of crushed aggregate. The bearing capacity of the sand is greatly enhanced since lateral displacement is eliminated. Although additional work is still required, it is expected that the sand grid system discussed in this report will ultimately result in a significant cost savings in embankment construction in Western Alaska
    • Quarterly Report 1: Progress on Evaluation of WTC7 Collapse

      Hulsey, J. Leroy; Xiao, Feng; Quan, Zhili (2015-10)