UID:
kobvindex_GFZ20201124142223
Format:
iv, 17 Seiten
,
Illustrationen
Series Statement:
Research report / Cold Regions Research and Engineering Laboratory 47
Content:
Summary: Various mechanical properties such as strength, elastic modulus, and density of TUTO tunnel and ramp ice were determined. Results of unconfined compressive strength, ring tensile strength, and flexural strength tests are given. Photographs of included bubbles and grain size and shape are shown for each of six types of ice tested. Petrofabric diagrams for each type of ice are included. No significant differences in strength were found between horizontal and vertical cores in the ice tunnel, although differences between types of ice are noted. Crushing strength values found for tunnel ice generally fit the empirical equation relating crushing strength to density which was found for high-density snows (Butkovich, 1956a). However the values for ramp ice do not fit the equation when the average density values are used, probably due to the layering. The empirical equation relating ring tensile strength to density of high-density snows (ibid.) gives results approximately 20% greater than those obtained for tunnel ice. It appears that grain size influences the results. Ice with large grains consistently gives lower values. Flexural strength of the ramp ice is about half that of the tunnel ice. Comparing these results with the ring tensile values leads to the conclusion that the beams tend to fail in the lowest-density (mostly bubbly) bands. Temperature curves as a function of depth into the wall and along the tunnel length are presented. A 30-day study of deformation in a 100 x 30 ft room at 650 ft. into the tunnel indicated that the room is closing primarily by a block action, with rates of closure being less only very near the walls.
Note:
CONTENTS
Preface
Summary
Introduction
Strength
Crushing strength
Ring tensile strength
Flexural strength
Static modulus of elasticity
Dynamic modulus of elasticity
Density of tunnel and ramp ice
Tunnel temperature measurements
Crystal size, bubble size, and ice fabrics
Deformation measurements
Discussion of strength test results
References
In:
Research report / Cold Regions Research and Engineering Laboratory, 47
Language:
English
Keywords:
Forschungsbericht
URL:
https://hdl.handle.net/11681/2698
