A consolidation test (Taylor, 1948) was conducted on a sample of soft Chicago silty clay. The specimen
Question:
A consolidation test (Taylor, 1948) was conducted on a sample of soft Chicago silty clay. The specimen had a dry weight of 343.57 g and a density of solids of 2.65 Mg/m3. The area of the ring was 93.31 cm2. A displacement transducer was used, which has a precision of one ten thousandth of an inch (1 x 10-4 in), and the incremental stresses applied to the specimen were recorded in kgf/cm2. Direct measurements of the thickness of the specimen were as follows:
1.254 in when under 1/8 kg/cm2
1.238 in when under 1/2 kg/cm2
1.215 in when under 1 kg/cm2
Deformations to the nearest 10-4 in recorded during the test are listed in Table P9.14. Required:
(a) Use a spreadsheet to plot the e versus log σ' and/or the e versus log σ' curve for this test.
Determine the pre-consolidation stress and the appropriate compression index.
(b) Use a spreadsheet to plot dial reading versus (t) 1/2 for each increment and determine cv. Plot cv versus log σ'.
(c) Same as part (b) only use the Casagrande log time-fitting method.
(d) For two increments, one before and one after the pre-consolidation stress, compare the values of cv as determined by the two fitting procedures
Step by Step Answer:
An Introduction to Geotechnical Engineering
ISBN: 978-0132496346
2nd edition
Authors: Robert D. Holtz, William D. Kovacs, Thomas C. Sheahan