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  • 1
    Signatur: ZSP-201-82/15
    In: CRREL Report, 82-15
    Beschreibung / Inhaltsverzeichnis: An experiment is described that demonstrates the balance between the ice and the unfrozen water in a frozen soil as water is removed. Nuclear magnetic resonance (NMR) is used to monitor the unfrozen water content as the soil is dehydrated by a molecular sieve material. Our results show that the unfrozen water content of a Morin clay soil remains constant until the total water content has been reduced to the point where no ice remains in the system. Once the ice is depleted, the unfrozen water content determined by NMR corresponds to the total water content of the soil determined by the weight of water removed by the molecular sieve material. Thus the validity of utilizing NMR in determining unfrozen water contents vs temperature is established.
    Materialart: Schriftenreihen ausleihbar
    Seiten: 8 Seiten , Illustrationen
    Serie: CRREL Report 82-15
    Sprache: Englisch
    Standort: AWI Archiv
    Zweigbibliothek: AWI Bibliothek
    Standort Signatur Erwartet Verfügbarkeit
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  • 2
    Signatur: ZSP-201-87/14
    In: CRREL Report, 87-14
    Beschreibung / Inhaltsverzeichnis: During February and March 1980 the physical properties of Weddell Sea pack ice were investigated via core drilling of 66 floes located along the transect of 600 nautical miles from 64°S to 74°S latitude at roughly 40°W longitude. These studies revealed widespread frazil ice in amounts not known to exist in Arctic sea ice of comparable age and thickness. It is estimated from structure studies of 62 of the 66 floes that 54% of the total ice production of the Weddell Sea is generated as frazil. The disposition and exceptional thickness of the frazil show that mechanisms other than surface turbulence effects are involved and imply that the circulation and structure of the water in the upper levels of the Weddell Sea are significantly different from those in the Arctic basin. Salinities of both first-year and multi-year floes are notably higher than those of their Arctic counterparts because summer surface melting is rare or absent in the Weddell Sea; in the Arctic, downward percolating meltwater flushes through the ice and lowers its salinity. Fluorescence was evaluated as a means of revealing biological activity in Weddell Sea pack ice. It proved useful as an index of combined living and dead material in the ice, but measurements failed to establish any consistent relationship between fluorescence and salinity as suggested be earlier work in the Weddell Sea.
    Materialart: Schriftenreihen ausleihbar
    Seiten: iv, 80 Seiten , Illustrationen
    Serie: CRREL Report 87-14
    Sprache: Englisch
    Anmerkung: CONTENTS Preface Introduction Sea ice structure and classification Logistics and field operations Analytical techniques Crystalline structure Fluorescence Results Salinity Crystalline structure Fluorescence Description of selected floes Conclusions Literature cited Appendix A: Floe descriptions
    Standort: AWI Archiv
    Zweigbibliothek: AWI Bibliothek
    Standort Signatur Erwartet Verfügbarkeit
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  • 3
    Schriftenreihen ausleihbar
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Dazugehörige Bände
    Signatur: ZSP-201-80/17
    In: CRREL Report, 80-17
    Beschreibung / Inhaltsverzeichnis: Construction pads made of snow were used to build two sections of the Trans Alaska Pipeline and a small gas pipeline during the winter of 1975-76. Construction during the winter has become increasingly common in the Arctic. Surface travel and the use of heavy construction equipment on the unprotected tundra have been severely restricted, even during the winter, so the use of temporary winter roads and construction pads built of snow and ice has been advocated and is being adopted. The three snow construction pads mentioned above were the first snow roads and construction pads used on a large scale in Alaska. Snow roads and construction pads have two objectives: to protect the underlying vegetation and upper layers of the ground, and to provide a hard, smooth surface for travel and the operation of equipment. Several types have been built, and a brief discussion is given of their history and classification systems. The three snow construction pads used in construction of the Trans-Alaska Pipeline and the small gas pipeline in 1975-76 were visited and observed while in use. The Globe Creek snow pad, about 50 miles north of Fairbanks, was built primarily of manufactured snow hauled to the site and watered. With very high densities this pad withstood heavy traffic and use by heavy construction equipment except on one steep slope. There, the use of tracked vehicles and vehicles without front wheel drive disaggregated the snow on and near the surface so that vehicles without front wheel drive were unable to climb the hill. The Toolik snow pad, just north of the Brooks Range, was built of compacted snow and proved capable of supporting the heaviest traffic and construction equipment. The fuel gasline snow pad ran from the northern Brooks Range to the Arctic Coast and also proved capable of supporting the necessary traffic. Both the Toolik snow pad and the fuel gasline snow pad failed in very early May because of unseasonably warm and clear weather before the associated construction projects were completed. However, the three snow pads must be considered successful. Common problems were the lack of snow, slopes, unseasonably warm spring weather, and inexperience on the part of contractors and construction personnel.
    Materialart: Schriftenreihen ausleihbar
    Seiten: v, 28 Seiten , Illustrationen
    Serie: CRREL Report 80-17
    Sprache: Englisch
    Anmerkung: CONTENTS Abstract Preface Introduction History of snow and ice roads Classification of snow and ice roads Snow pads used by Alyeska during the winter of 1975-1976 The Globe Creek snow pad The Toolik snow pad The gasline snow pad Summary and conclusions Literature cited
    Standort: AWI Archiv
    Zweigbibliothek: AWI Bibliothek
    Standort Signatur Erwartet Verfügbarkeit
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  • 4
    Schriftenreihen ausleihbar
    Schriftenreihen ausleihbar
    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Dazugehörige Bände
    Signatur: ZSP-201-80/11
    In: CRREL Report, 80-11
    Beschreibung / Inhaltsverzeichnis: Four types of roof leaks occurred at a new school building in Chevak, Alaska: 1) blowing snow entered the roof through eave vents and then melted, 2) slush and ice in roof valleys caused meltwater to overflow the valley flash­ing and run into the building, 3) water entered at a roof/wall intersection and 4) in many areas water entered through gaps in the sloping plywood deck. Sealing the eave vents made it impossible for blowing snow to enter the roof at the eaves. Electric heat tapes eliminated the valley icing problem. Missing flashing was responsible for the roof/wall intersection leaks. The absence of a vapor barrier in the roof was the cause of many leaks. We recom­mended that the roof be repaired from the exterior by removing component elements down to the plywood deck,installing an adhered continuous vapor barrier and reassembling the roof. An alternative roof cladding of compos­ition shingles was discussed as was conversion to a “cold roof.” The roof was repaired and modified following our recommendations, and problems appear to have been solved.
    Materialart: Schriftenreihen ausleihbar
    Seiten: iv, 12 Seiten , Illustrationen
    Serie: CRREL Report 80-11
    Sprache: Englisch
    Anmerkung: CONTENTS Abstract Preface Conversion factors Introduction Description of school Roof problems Snow infiltration leaks Valley leaks Intersection leaks Condensation leaks Tests to verify the cause of condensation leaks Eliminating the condensation leaks Recommendations for eliminating condensation leaks Repairing existing roof An alternative roof cladding The "cold roof" alternative Repairs and modifications Summary and conclusions
    Standort: AWI Archiv
    Zweigbibliothek: AWI Bibliothek
    Standort Signatur Erwartet Verfügbarkeit
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  • 5
    Signatur: ZSP-201-82/26
    In: CRREL Report, 82-26
    Beschreibung / Inhaltsverzeichnis: The Caribou-Poker Creeks Research Watershed is a small (101.5-sq km) drainage basin located 48 km northwest of Fairbanks, Alaska. Elevations within the watershed range from 210 to 826 m, and approximately 28% of its area is underlain by permafrost. Climatic differences between the watershed and Fairbanks are primarily due to the higher elevation of the watershed. Generally the watershed climatic sites are warmer in winter and cooler in summer than Fairbanks. Within the watershed the greatest temperature contrasts exist in winter, when the valley-bottom sites are beneath the regional air temperature inversion, and the higher sites are above it. From May through September the total precipitation averages 270 mm, 1.47 times that received at Fairbanks. The annual precipitation is about 1.7 times that of Fairbanks. The historical precipitation record at Fairbanks indicates that summer precipitation was below the long-term normal in eight of the eleven years of watershed measurements (1969-1980); no climatic extremes occurred during this period. An analysis of annual streamflow data showed an inconsistency of baseflow recessions from year to year. The runoff-rainfall ratio for individual summer storms averaged 0.35 for Caribou Creek. Comparisons of spot discharge measurements of predominantly permafrost and non-permafrost subwatersheds showed that permafrost-dominated watersheds have a much flashier response to precipitation than non-permafrost watersheds. A comparison of the annual flow distribution of the watershed indicated that Caribou Creek has lower summer and higher winter discharges per unit area than the Chena or Salcha Rivers.
    Materialart: Schriftenreihen ausleihbar
    Seiten: 42 Seiten , Illustrationen
    Serie: CRREL Report 82-26
    Sprache: Englisch
    Anmerkung: CONTENTS Abstract Preface Introduction Setting Geology and soils Vegetation Climate Air temperature Precipitation Hydrology Annual and monthly runoff Individual storms Baseflow recessions Spatial flow variability Temporal flow variability Summary and conclusions Literature cited Appendix A: Station histories
    Standort: AWI Archiv
    Zweigbibliothek: AWI Bibliothek
    Standort Signatur Erwartet Verfügbarkeit
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  • 6
    Schriftenreihen ausleihbar
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Dazugehörige Bände
    Signatur: ZSP-201-88/16
    In: CRREL Report, 88-16
    Beschreibung / Inhaltsverzeichnis: Unfrozen water content as a function of temperature was measured in the laboratory using nuclear magnetic resonance (NMR) for a Windsor sandy loam soil. The data were related to previously measured soil moisture retention data through the modified Clapeyron equation with suitable adjustment for surface tension. The results show the usefulness of extending the soil freezing curve to temperatures only slightly below freezing and the soil water curve to very great suction.
    Materialart: Schriftenreihen ausleihbar
    Seiten: iii, 42 Seiten , Illustrationen
    Serie: CRREL Report 88-16
    Sprache: Englisch
    Anmerkung: CONTENTS Abstract Preface Introduction Soil variable ø SWC and SFC similarity Mathematical representation of SWC and SFC data NMR measurement of unfrozen water content Characterization of SWC Discussion Conclusions Literature cited Appendix A: Soil freezing curve data Appendix B: Error analysis Appendix C: Soil water curve data
    Standort: AWI Archiv
    Zweigbibliothek: AWI Bibliothek
    Standort Signatur Erwartet Verfügbarkeit
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  • 7
    Schriftenreihen ausleihbar
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Dazugehörige Bände
    Signatur: ZSP-201-88/18
    In: CRREL Report, 88-18
    Beschreibung / Inhaltsverzeichnis: The results of a laboratory testing program, carried out to compare two independent methods for determining the unfrozen water content of soils, are described. With the time domain reflectometry method, the unfrozen water content is inferred from a calibration curve of apparent dielectric constant vs volumetric water content, determined by experiment. Previously, precise calibration of the TDR technique was hindered by the lack of a reference comparison method, which nuclear magnetic resonance now offers. This has provided a much greater scope for calibration, including a wide range of soil types and temperature (unfrozen water content). The results of the testing program yielded a relationship between dielectric constant and volumetric unfrozen water content that is largely unaffected by soil type, although a subtle but apparent dependency on the texture of the soil was noted. It is suggested that this effect originates from the lower valued dielectric constant for absorbed soil water. In spite of this, the general equation presented may be considered adequate for most practical purposes. The standard error of estimate is 0.015 cc/cc, although this may be reduced by calibrating for individual soils. Brief guidelines on system and probe design are offered to help ensure that use of the TDR method will give results consistent with the relationship presented.
    Materialart: Schriftenreihen ausleihbar
    Seiten: ii, 16 Seiten , Illustrationen
    Serie: CRREL Report 88-18
    Sprache: Englisch
    Standort: AWI Archiv
    Zweigbibliothek: AWI Bibliothek
    Standort Signatur Erwartet Verfügbarkeit
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  • 8
    Schriftenreihen ausleihbar
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Dazugehörige Bände
    Signatur: ZSP-201-84/16
    In: CRREL Report, 84-16
    Beschreibung / Inhaltsverzeichnis: Phase composition curves are presented for a typical saline silt from Lanzhou, P.R.C., and compared to some silts from Alaska. The unfrozen water content of the Chinese silt is much higher than that of the Alaskan silts due to the large amount of soluble salts present in the silts from China, which are not present in silt from interior Alaska. When the salt is removed, the unfrozen water content is then similar for both the Chinese and Alaskan silt. Here we introduce a technique for correcting the unfrozen water content of partially frozen soils due to high salt concentrations. We calculate the equivalent molality of the salts in the unfrozen water at various temperatures from a measurement of the electrical conductivity of the extract from saturated paste.
    Materialart: Schriftenreihen ausleihbar
    Seiten: iii, 25 Seiten , Illustrationen
    Serie: CRREL Report 84-16
    Sprache: Englisch
    Anmerkung: Contents Abstract Preface Introduction Background Materials Sample preparation Nuclear magnetic resonance Specific surface area Electrical conductivity Results and discussion Summary Literature cited Appendix A: Unfrozen water content vs temperature data for Lanzhou silt
    Standort: AWI Archiv
    Zweigbibliothek: AWI Bibliothek
    Standort Signatur Erwartet Verfügbarkeit
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  • 9
    Schriftenreihen ausleihbar
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Dazugehörige Bände
    Signatur: ZSP-202-99
    In: Research report / Cold Regions Research and Engineering Laboratory, 99
    Beschreibung / Inhaltsverzeichnis: Summary: A study of how age hardening affects the various mechanical properties of processed snow was made. A description of how the age hardening process is affected by the variables of density, temperature, grain size, and shape is given. An empirical equation relating creep rate to stress, age, and density was obtained. The study also shows that the various mechanical properties are related to age by an exponential function.
    Materialart: Schriftenreihen ausleihbar
    Seiten: iv, 12 Seiten , Illustrationen
    Serie: Research report / Cold Regions Research and Engineering Laboratory 99
    Sprache: Englisch
    Anmerkung: CONTENTS Preface Summary Introduction Experimental facilities Experimental in-place measurements Density and homogeneity of processed snow Ram hardness Temperature measurements Mechanical properties Unconfined compressive strength Stress-strain relationships in unconfined compress ion Creep in unconfined compression Tensile strength Discussion of results References
    Standort: AWI Archiv
    Zweigbibliothek: AWI Bibliothek
    Standort Signatur Erwartet Verfügbarkeit
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  • 10
    Schriftenreihen ausleihbar
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Dazugehörige Bände
    Signatur: ZSP-201-77/6
    In: CRREL Report, 77-6
    Beschreibung / Inhaltsverzeichnis: It has been reported that small arms projectiles are inherently unstable in snow and that snow has an unexpectedly high ability to stop them and other fast-moving projectiles. Field tests showed that the typical subarctic snow of interior Alaska can be used effectively to provide protection from both rifle and machine gun fire. The undisturbed snow had an average density of 0.18 g/cu. cm., but simple processing, such as shoveling, increased the density to around 0.34 g/cu. cm. Further processing increased the density to above o.40 g/cm3 but densities much above that value were difficult to obtain with simple hand equipment. Tests of the M16 rifle and M60 and M2HB machine guns showed that bullet penetration was inversely related to density - the higher the density the lower the bullet penetration. Design values for the three weapons were determined. A number of types of snow trenches and structures were designed and tested. They were found to provide good protection, in part since bullets showed a strong tendency to ricochet from the snow surface when striking it at a low angle. Burlap bags were filled with snow to revet structures and worked very well. Several types of Russian defensive works of snow were tested but proved unsuitable in the light, weak subarctic snow. The times required for troops to build several types of structures using only shovels and scoops were recorded.
    Materialart: Schriftenreihen ausleihbar
    Seiten: vi, 23 Seiten , Illustrationen
    Serie: CRREL Report 77-6
    Sprache: Englisch
    Anmerkung: CONTENTS Abstract Preface Summary Background Objectives Subarctic snow General Snow processing Construction productivity Shovel capacity Snow piles Bullet behavior and penetration in snow Test procedure M16 M60 ball M60 tracers .50 caliber Tumbling Bullet deformation and breakage Design penetration values Defensive works of snow Revetments Snow bags The snow trench The hardened snow trench Breastworks and bunkers Evaluation of foreign technology Russian expedient snow trenches Snow blocks and block structures The snow arch An expedient shelter Conclusions Recommendations Literature cited
    Standort: AWI Archiv
    Zweigbibliothek: AWI Bibliothek
    Standort Signatur Erwartet Verfügbarkeit
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