ISSN: 1945-7545
CODEN: GTJODJ
Page Count: 10

Fabrication of Silty Sand Specimens for Large- and Small-Scale Tests

Brandon, TL
Assistant professor of civil engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA

Clough, GW
Dean, College of Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA

Rahardjo, PP
Lecturer of civil engineering, Parahyangan Catholic University, Bandung,

Abstract

In the course of research concerning the relation of cone penetration results and liquefaction resistance, it was necessary to develop a reliable method for preparation of silty sand specimens for laboratory triaxial testing (3.6 by 7.1 cm in diameter) and for a large-scale calibration chamber (1.5 by 1.5 m in diameter). The objective was to simulate the in situ soil fabric and to allow for creation of a range of densities. Four alternate procedures were studied, including kneading compaction, pluviation through air, pluviation through vacuum, and consolidation from a slurry. The primary conclusions from the research were:

1. Kneading compaction is effective in producing laboratory specimens with a range of densities, but it is not an effective procedure for placing these materials in the large-scale calibration chamber.

2. Pluviation through air and vacuum creates specimens with unrealistically high void ratios. Obtaining a range of densities was not possible.

3. Slurry consolidation proved to be successful in creating specimens with a range of densities and was the technique chosen for the calibration chamber.

Only vertical drainage was used in the calibration chamber to avoid formation of a specimen with a soft core surrounded by stiff sides. Eighteen to twenty days were required for consolidation, and the density of the specimens along a vertical profile varied by no more than 6% from the average density. There was little evidence of segregation of fines.

Keywords:
consolidation, pluviation, compaction, sample fabrication, large-scale testing

Paper ID: GTJ10190J
DOI: 10.1520/GTJ10190J
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