UID:
kobvindex_GFZ20201118151011
Format:
iv, 12 Seiten
,
Illustrationen
Series Statement:
Research report / Cold Regions Research and Engineering Laboratory 41
Content:
Summary: Laboratory experiments on the creep of sifted snow under uniaxial, hydrostatic, and confined-side compressive stresses are described, and the results are discussed on the basis of an additive theory for combined stresses. Stress (4-40 psi) and temperature (-3.6°C to -13.6°C) dependence was investigated for 35 samples (initial density = 0.4 g/cm^3) subjected to uniaxial and hydrostatic stress for 200-sec time increments. Another series of 104 samples (initial densities 0.36-0.63) was subjected to uniaxial, hydrostatic, and confined-side compressive stresses until an arbitrary change in density was reached. In all cases the applied stress ultimately became a shear stress acting between grains, the open structure reacting differently to combined stresses and separate uniaxial stresses. An activation energy of 13,400 cal/mol was obtained from the first group of tests.
Note:
CONTENTS
Preface
Summary
Introduction
Experimental
General
Apparatus
Procedure
Theoretical relations
Additive theory
Relationship between tests run for constant change in density and tests for constant time
Results and discussion
Group I experiments
Group II experiments
Stress dependence for group II tests
Variability
Time dependence
Activation energy
Relations between creep rates under different stress conditions
Density dependence
Lateral stress for confined-side tests
Conclusions
References
In:
Research report / Cold Regions Research and Engineering Laboratory, 41
Language:
English
Keywords:
Forschungsbericht
URL:
https://hdl.handle.net/11681/2733
