Tensile Strength of Frozen Silt

Tensile Strength of Frozen Silt
Author: Zhu Yuanlin
Publisher:
Total Pages: 40
Release: 1987
Genre: Frozen ground
ISBN:

Constant strain-rate tension tests were conducted on remolded saturated frozen Fairbanks silt at various temperatures, strain rates, and densities. It was found that the critical strain rate of the ductile-brittle transition is not temperature-dependent at temperatures down to -5 C, but varies with density. The peak tensile strength decreases considerable with decreasing strain rate for ductile failure, but it decreases slightly with increasing strain rate for brittle fracture. The failure strain remains almost constant at temperatures lower than about -2 C, but it varies with density and strain rate at -5 C. The initial tangent modulus is independent of strain rate and increases with decreasing temperature and density. Keywords: Frozen mechanics, Frozen soil, Silt, Soil, Strain, Strength.

Creep and Strength Behavior of Frozen Silt in Uniaxial Compression

Creep and Strength Behavior of Frozen Silt in Uniaxial Compression
Author: Zhu Yuanlin
Publisher:
Total Pages: 84
Release: 1987
Genre: Frozen ground
ISBN:

Uniaxial constant-stress and constant-strain-rate compression tests were conducted on more than 200 remolded, saturated, frozen specimens of rates show a close strength correspondence between the constant-stress and constant-strain-rate tests. All of these complete stress vs strain rate curves could not be described by a single power law or exponential equation, indicating that different deformation mechanisms are dominant within different ranges of strain rate.

Strain Rate Effect on the Strength of Frozen Silt

Strain Rate Effect on the Strength of Frozen Silt
Author: F. D. Haynes
Publisher:
Total Pages: 36
Release: 1975
Genre: Silt
ISBN:

Uniaxial compression and tension tests were conducted on frozen Fairbanks silt at a temperature of -10 C.A relatively stiff testing machine was operated at a constant displacement rate for each test. The tests showed that compressive strength is very sensitive to strain rate and the tensile strength is relatively insensitive to it. The compressive strength increased ten times over a srain rate range of .00012/S to 2.9/s. As was found in other investigations, tangent moduli increased slightly with greater strain rates. The specific eney increased at higher strain rates for compression tests and decreased slightly for tension tests. For increased strain rates, uniaxial compression strength showed no tendency to plateua; nor did the specific energy a minimum during uniaxial tensile testing. (Author).

An Introduction to Frozen Ground Engineering

An Introduction to Frozen Ground Engineering
Author: Orlando B. Andersland
Publisher: Springer Science & Business Media
Total Pages: 363
Release: 2013-11-11
Genre: Science
ISBN: 1475722907

Frozen Ground Engineering first introduces the reader to the frozen environment and the behavior of frozen soil as an engineering material. In subsequent chapters this information is used in the analysis and design of ground support systems, foundations, and embankments. These and other topics make this book suitable for use by civil engineering students in a one-semester course on frozen ground engineering at the senior or first-year-graduate level. Students are assumed to have a working knowledge of undergraduate mechanics (statics and mechanics of materials) and geotechnical engineering (usual two-course sequence). A knowledge of basic geology would be helpful but is not essential. This book will also be useful to advanced students in other disciplines and to engineers who desire an introduction to frozen ground engineering or references to selected technical publications in the field. BACKGROUND Frozen ground engineering has developed rapidly in the past several decades under the pressure of necessity. As practical problems involving frozen soils broadened in scope, the inadequacy of earlier methods for coping became increasingly apparent. The application of ground freezing to geotechnical projects throughout the world continues to grow as significant advances have been made in ground freezing technology. Freezing is a useful and versatile technique for temporary earth support, groundwater control in difficult soil or rock strata, and the formation of subsurface containment barriers suitable for use in groundwater remediation projects.

Frozen Ground Engineering

Frozen Ground Engineering
Author: Orlando B. Andersland
Publisher: John Wiley & Sons
Total Pages: 384
Release: 2003-11-05
Genre: Technology & Engineering
ISBN: 9780471615491

This new edition of Frozen Ground Engineering gives a peerless presentation of soil mechanics for frozen ground conditions and a variety of frozen ground support systems used on construction projects worldwide. An authoritative update of the industry standard, this Second Edition covers the essential theory, applications, and design methods using frozen ground in the construction of deep shafts, tunnels, deep excavations, and subsurface containment barriers. New material features design models for pavement structures used in seasonal frost and permafrost areas, new information on the movement of fluid phase contaminants in frozen ground, and helpful appendices offering guidance on common frozen ground tests and SI unit conversions. This new edition gives the essential information engineers, geologists, and students need in a complete reference, including up-to-date information on: Sensitivity of frozen ground to climate change Experimental work on frozen soil creep and strength Monitoring creep in frozen slopes Frost protection of foundations using ground insulation Highway insulation Load restrictions for seasonal frost areas

Technical Report

Technical Report
Author: Cold Regions Research and Engineering Laboratory (U.S.)
Publisher:
Total Pages: 766
Release: 1977
Genre: Frozen ground
ISBN:

Instabilities in alpine permafrost: strength and stiffness in a warming regime

Instabilities in alpine permafrost: strength and stiffness in a warming regime
Author: Yuko Yamamoto
Publisher: vdf Hochschulverlag AG
Total Pages: 519
Release: 2014-08-20
Genre: Science
ISBN: 3728136409

Alpine permafrost exists at high altitude at lower latitudes, such as in the Swiss Alps. Accelerating climate change, including rising mean annual air temperature and extreme rainfall conditions in alpine regions induces permafrost degradation. The warming of permafrost causes accelerated creep of rock glaciers, due to increased unfrozen water content and higher deformability of the ice phase. Recently, the development of deepening depressions has been observed in several rock glaciers in Switzerland, and the changes in land surface characteristics and drainage systems may initiate slope instabilities in rock glaciers. The main aim of this thesis is to characterise the strength and stiffness of alpine frozen soil in rock glaciers. To this end, the geotechnical response, such as creep and failure of frozen soil was investigated through a triaxial stress path testing programme with novel measurement systems for detecting acoustic emissions and measuring volumetric change. In addition, the resistance to crack initiation and propagation was investigated through a beam bending test programme on rectangular artificially frozen soil specimens, using the acoustic emission measurement system. The evaluation of laboratory tests on artificially frozen soil specimens implied that the development of deep depressions in rock glaciers occurs through differential creep and thermal degradation, and that the rate of deformation has the potential to lead to instabilities in rock glaciers. A comparison of the simulation results with the experimental data demonstrated that the semi-coupled model was successful in simulating the most important aspects of the temperature-dependent stress-strain relationship for the frozen soil behaviour that was measured at the element scale. This thesis contributes to an understanding of the variations in geotechnical response of alpine permafrost, by investigating the behaviour of artificially frozen soil specimens experimentally and numerically with time and temperature under specific stress paths. However, further investigations are necessary to assess the long-term stability of rock glaciers affected by climate change.