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  • 1
    Series available for loan
    Series available for loan
    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-82/34
    In: CRREL Report, 82-34
    Description / Table of Contents: The ice discharge through an opening in an ice control structure was documented to be a function of the floe size, ice type, ice floe conditions and vessel direction. The model data for the average ice discharge per vessel transit scaled to prototype values compared favorably with data taken at the St. Marys River ice control structure (ICS). The model results of the force measurements were also consistent with data taken at the St. Marys ICS. The dynamic loading conditions were independent of vessel direction. The dynamic loading to the structure using 3 types of ice (plastic, natural and urea-doped) showed a considerable difference in their means and standard deviations. The urea-doped ice was evaluated for dynamic loading conditions, and reasonable peak values of 3 to 5 times the mean load at each measuring position were recorded, independent of vessel direction. It appears that synthetic random ice floes may be used in model studies where ice discharge through an opening in a structure needs to be documented. This study shows the synthetic random ice floe discharge to fall reasonably within the values obtained for natural ice discharge for both rafted and non-rafted ice fields above the ICS. However, the question of whether synthetic ice can be used for analyzing force distributions and dynamic force loading criteria cannot be fully answered at this time because the load distributions of the synthetic and natural floes appear to differ.
    Type of Medium: Series available for loan
    Pages: 68 Seiten , Illustrationen
    Series Statement: CRREL Report 82-34
    Language: English
    Note: CONTENTS Abstract Preface Introduction Scope of work Ice discharge from Lake Huron into St. Clair River Water velocity profiles at Port Huron Ice conditions Physical model Basis for selection Description Instrumentation Model ice control structure Open water calibration Open water tests Experimental procedures and techniques Ice cover calibration Ice control structure orientation Analysis of ice discharge due to ship transits Natural ice Synthetic ice Forces on the ice control structure Static measurements Dynamic force measurements Potential additional shear stresses Anticipated ice conditions with ICS Conclusions Literature cited Appendix A. Application of model results Appendix B. Suggested additional studies Appendix C. Derivation of ice discharge
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  • 2
    Call number: ZSP-202-315
    In: Research report
    Description / Table of Contents: CONTENTS: Preface. - Introduction. - Part 1:Mesoscale strain measurements on the Beaufort Sea pack ice. - Abstract. - Introduction. - Previous work. - Site location. - Results. - Correlation of synoptic aerial photography with measured strains. - Correlation of estimated wind stress and strain. - Conclusions. - Literature cited. - Part II: Structure of a multiyear pressure ridge. - Abstract. - Introduction. - Profiles. - Internal properties. - Largest ridge sail. - Conclusions. - Literature cited. - Part III: Top and bottom roughness of a multiyear ice floe. - Abstract. - Introduction. - Results. - Literature cited. - Part IV:Airphoto analysis of ice deformation in the Beaufort Sea Abstract. - Introduction. - Study area. - Method of analysis. - Ice deformations. - Net deformational changes. - Pressure ridge distribution. - Summary and conclusions. - Literature cited. - Part V: Data on morphological and physical characteristics of sea ice in the Beaufort Sea.
    Description / Table of Contents: Mesoscale strain measurements on the Beaufort Sea pack ice; Structure of a multiyear pressure ridge; Top and bottom roughness of a multiyear ice floe; Airphoto analysis of ice deformation in the Beaufort Sea; Data on morphological and physical characteristics of sea ice in the Beaufort Sea.
    Type of Medium: Series available for loan
    Pages: iii, 66 Seiten , Illustrationen
    Series Statement: Research report / Cold Regions Research and Engineering Laboratory, CRREL, US Army Material Command 315
    Language: English
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  • 3
    Series available for loan
    Series available for loan
    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-82/9
    In: CRREL Report, 82-9
    Description / Table of Contents: This study deals with the distribution of forces along the converging boundaries of the Port Huron, Michigan, region where unconsolidated ice in Lake Huron is held against wind and water stresses. An experimental basin was built to induce uniform shear stress on the model ice cover by flowing water beneath the ice. The boundary segments, which held the ice cover in the region, were instrumented to measure force in the normal and tangential directions. The distribution of normal forces along the boundary was compared with as distribution derived by using a theoretical model. An ice control structure (ICS) was installed in the basin and experiments were conducted to measure the forces on the ICS and the ice release through the opening in the ICS during simulated ship passages. The experimental results are presented in a nondimensional form. In addition, the force per unit length on the ICS and the area of ice released through its opening were estimated for the expected wind conditions at the Port Huron site.
    Type of Medium: Series available for loan
    Pages: v, 27 Seiten , Illustrationen
    Series Statement: CRREL Report 82-9
    Language: English
    Note: CONTENTS Abstract Preface List of symbols Introduction Theoretical models Case 1 Case 2 Case 3 Experimental program Experimental facility Scaling factors Experimental results Analysis of wind data for lower Lake Huron Summary and conclusions Release of ice through the opening of an ICS Ice forces on the ice control structure Ice forces on ice control structure from a large unconsolidated ice cover Literature cited Appendix A. Equation for the stress resultants and velocities of the ice cover Appendix B. Monthly summary of wind data at Port Huron
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  • 4
    Call number: ZSP-201-76/18
    In: CRREL Report, 76-18
    Description / Table of Contents: Three surface elevation and ice thickness profiles obtained during the 1972 Arctic Ice Dynamics Joint Experiment on a multiyear ice floe were analyzed to obtain relationships between surface elevation, thickness and physical properties of the ice. It was found that for ice freeboards from 0.10 m to 1.05 m above sea level a linear relationship between ice density and freeboard could be postulated. The equation for the regression line is: Ice density = -194f' + 974 kg/cu m where f' is the ice freeboard plus snow depth in ice equivalent at the point in question. This statistical relationship is consistent with observed physical properties, which indicate that as the ice freeboard increases, ice salinity decreases and the higher freeboard or thicker ice therefore decreases in density. Using this variable density with freeboard relationship, a model was constructed to predict ice thickness, given ice freeboard and snow depth alone. This prediction is desirable, since snow depth and freeboard are relatively easy to obtain, whereas ice thickness can usually be obtained only by drilling through the ice. The model was compared with two other models. It was found that the variable density prediction model gave the best approximation to observed ice thickness, with a standard error between the measured and predicted value of about 0.4 m, compared with errors from 50 to 100% higher for the other two models.
    Type of Medium: Series available for loan
    Pages: v, 25 Seiten , Illustrationen
    Series Statement: CRREL Report 76-18
    Language: English
    Note: Contents Abstract Preface Summary Introduction Previous work Results Models for predicting thickness from ice freeboard Comparison between measured and predicted thicknesses Spectral behavior of measured and predicted profiles Comparisons of ice thickness using airborne laser profilometry Conclusions Literature cited Appendix A: Misgivings on isostatic imbalance as a mechanism for sea ice cracking
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  • 5
    Call number: ZSP-201-87/2
    In: CRREL Report, 87-2
    Description / Table of Contents: This is the third in a series of four reports on the laboratory and field testing of a number of road and airfield subgrades, covering the laboratory repeated-load triaxial testing of five soils in the frozen and thawed states and analysis of the resulting resilient modulus measurements. The laboratory testing procedures allow simulation of the gradual increase in stiffnessfound in frost-susceptible soils after thawing. The resilient modulus is expressed in a nonlinear model in terms of the applied stresses, the soil moisture tension level (for unfrozen soil), the unfrozen water content (for frozen soil) and the dry density. The resilient modulus is about 10 GPa for the frozen material at temperatures in the range of -5° to -8° C. The decrease in modulus with increasing temperature was well-modeled in terms of the unfrozen water content. Upon thaw, the modulus dropped to about 100 MPa and generally increased with increasing confining stress and decreased with increasing principal stress ratio. The modulus also increased with the soil moisture tension level. The resilient Poisson's ratio did not appear to be a systematic function of any of the test variables.
    Type of Medium: Series available for loan
    Pages: iii, 36 Seiten , Illustrationen
    Series Statement: CRREL Report 87-2
    Language: English
    Note: CONTENTS Abstract Preface Introduction Test sections and materials Specimen preparation Test soils Asphalt concrete Laboratory testing Soil testing Waveforms of applied stress Asphalt concrete Data reduction and analysis Soil Asphalt concrete Results and discussion General Resilient modulus Summary Conclusions Literature cited Appendix A: Soil moisture tension versus water content for several test soils Appendix B: Tabulated results for all tests on frozen and thawed soils
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  • 6
    Call number: ZSP-201-83/21
    In: CRREL Report, 83-21
    Description / Table of Contents: The probability density function of the gouge depths into the sediment is represented by a simple negative exponential over four decades of gouge frequency. The exceedance probability function is, therefore, e to the -lambda d, where d is the gouge depth in meters and lambda is a constant. The value of lambda shows a general decrease with increasing water depth, from 9/m in shallow water to less than 3/m in water 30 to 35 m deep. The deepest gouge observed was 3.6 m, from a sample of 20,354 gouges that have depths greater than or equal to 0.2 m. The dominant gouge orientations are usually unimodal and reasonably clustered, with the most frequent alignments roughly parallel to the general trend to the coastline. The value of N(bar) sub 1, the mean number of gouges (deeper than 0.2 m) per kilometer measured normal to the trend of the gouges, varies from 0.2 for protected lagoons to 80 in water between 20 and 38 m deep in unprotected offshore regions. The distribution of the spacings between gouges as measured along a sampling track is a negative exponential. The form of the frequency distribution of N sub 1 varies with water depth and is exponential for lagoons and shallow offshore areas, previously skewed for 10 to 20 m depths off the barrier islands, and near-normal for deeper water. As a Poisson distribution gives a reasonable fit to the N sub 1 distributions for all water depths, it is suggested that gouging can be taken as approximating a Poisson process in both space and time. The distributions of the largest values per kilometer of gouge depths, gouge widths, and the heights of the lateral embankment of sediments plowed from the gouges are also investigated.
    Type of Medium: Series available for loan
    Pages: 40 Seiten , Illustrationen, 1 Karte
    Series Statement: CRREL Report 83-21
    Language: English
    Note: CONTENTS Abstract Preface Introduction Background and environmental setting Data collection and terminology Data analysis Gouge depths Gouge orientation Gouge frequency Extreme value analysis Applications to offshore design Gouge depth Extreme value statistics Burial depths Conclusion Literature cited Appendix A: Detailed bathymetric map of the Alaskan portion of the Beaufort Sea
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  • 7
    Series available for loan
    Series available for loan
    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-83/19
    In: CRREL Report, 83-19
    Description / Table of Contents: Small-scale laboratory experiments were conducted on model bridge piers in the CRREL test basin. The experiments were performed by pushing model ice sheets against structures and monitoring the ice forces during the ice/structure interaction. The parameters, varied during the test program, were the geometry of the bridge piers and the velocity, thickness, and flexural strength of the ice. The results are presented in the form of ice forces on sloping and vertical structures with different geometries. During ice action on sloping structures, a phenomenon of transition of failure mode from bending to crushing was observed as the ice velocity was steadily increased.
    Type of Medium: Series available for loan
    Pages: 17 Seiten , Illustrationen
    Series Statement: CRREL Report 83-19
    Language: English
    Note: CONTENTS Abstract Preface Introduction Tests Results Ice forces on inclined structures Transition of ice action due to velocity increase Aspect ratio Bridge pier nose geometry Conclusions Literature cited
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  • 8
    Series available for loan
    Series available for loan
    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-82/13
    In: CRREL Report, 82-13
    Description / Table of Contents: Frost heave is analyzed for the common case in which some ice penetrates the soil. In this situation, heave is due to the accumulation of soil-free ice just within the frozen zone, behind a frozen fringe of finite thickness. Heat and mass transport within and across that fringe are crucial processes in the dynamics of heave. This analysis concentrates on activity within the fringe, also connecting that activity to heat and mass flows in the more frozen and unfrozen zones. Each component in a set of governing differential equations is developed from rational physics and thermodynamics, using previous experimental work. It is assumed that the soil ice grows through interconnected interstices; hence it constitutes and can move as a rigid body. When the assumption is translated into mathematical terms, it completes the governing equations. The model resulting from these considerations is a one-dimensional finite element computer program that solves the equations for arbitrary initial and boundary conditions. The model is used to simulate the heave history of a hypothetical soil column frozen unidirectionally and subjected to a surcharge. The results are gratifying in that they predict qualitatively the characteristics of numerous laboratory observations. Some questions about the completeness of the theory remain, and strict verification of the model awaits further experimentation and better parameter identification.
    Type of Medium: Series available for loan
    Pages: iii, 11 Seiten , Illustrationen
    Series Statement: CRREL Report 82-13
    Language: English
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  • 9
    Series available for loan
    Series available for loan
    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-80/3
    In: (DE-B103)105551, CRREL Report
    Description / Table of Contents: Revegetation techniques were investigated for gravel soils in cold regions. Two gravel soil test sites were established in Hanover, New Hampshire, and Fairbanks, Alaska. During three growing seasons, we studied the applicability and cost effectiveness of various nutrient sources and mulch materials. The nutrient sources included sewage sludge (at 40, 60 and 80 tons/acre) and commercial fertilizer (at 200, 400 and 600 lb/acre). The mulching materials were wood fiber mulch with various types of tackifiers, peat moss, and sewage sludge. The effects of refertilization during the second growing season were also studied. At both sites the use of sewage sludge produced superior results in many respects to the use of fertilizer at the application rates studied. Grasses receiving sludge showed better establishment rates and greater plant cover and growth, and were able to withstand the hot drying conditions encountered during the summer months. Slightly quicker grass establishment was noted at the higher rates of application of each nutrient source in Fairbanks, while grass establishment at all sludge rates was good in Hanover. All fertilizer treatments performed poorly in Hanover. No evidence of winter injury to the grasses was noted in any of the treatments. Supplemental applications of nitrogen fertilizer in Hanover during spring of the second growing season proved highly beneficial. The fertilizer helped maintain grass growth even during dry summer conditions. The mulches were applied at the rate of 2,000 lb/acre. They were found to be important in providing a more nearly optimum environment for seedling establishment. Wood fiber mulch and the commercial Wood Fiber Mulch 2000, generally, were the best performers.
    Type of Medium: Series available for loan
    Pages: vi, 21 Seiten , Illustrationen
    Series Statement: CRREL Report 80-3
    Language: English
    Note: CONTENTS Abstract Preface Introduction Literature review Experimental design Climate Results and discussion Nutrient sources Mulches Soil fertility Cost analysis Summary and conclusions Literature cited
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  • 10
    Series available for loan
    Series available for loan
    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-79/19
    In: CRREL Report, 79-19
    Description / Table of Contents: The critical velocities of loads moving over floating ice plates have been determined by several authors. In all these analyses it was assumed that the in-plane force field in the ice cover is zero. However, due to constrained thermal strains, in-plane forces do occur in the field. The purpose of the present paper is to determine their effect upon the critical velocities of the moving loads. It is shown that a uniform compression force field reduces the critical velocity, whereas a tension force field has the opposite effect.
    Type of Medium: Series available for loan
    Pages: ii, 12 Seiten , Illustrationen
    Series Statement: CRREL Report 79-19
    Language: English
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