A clay soil, tested in a consolidometer, showed a decrease in void ratio from 1.20 to 1.10 when the presure was increased from 0.25 to 0.50 kgf/cm². Calculate the coefficient of compressibility (a) and the coefficient of volume compressibility (m). If the coefficient of consolidation (c) determined in the test for the given stress increment was 10 m²lyear, calculate the coefficient of permeability in cm/s. osis ass 900 220 If the sample tested at the site was taken from a clay layer 3.0 m in thickness, determine the consolidation settlement resulting from the given stress increment.

A clay soil, tested in a consolidometer, showed a decrease in void ratio from 1.20 to 1.10 when the presure was increased from 0.25 to 0.50 kgf/cm². Calculate the coefficient of compressibility (a) and the coefficient of volume compressibility (m). If the coefficient of consolidation (c) determined in the test for the given stress increment was 10 m²lyear, calculate the coefficient of permeability in cm/s. osis ass 900 220 If the sample tested at the site was taken from a clay layer 3.0 m in thickness, determine the consolidation settlement resulting from the given stress increment.

Principles of Geotechnical Engineering (MindTap Course List)

9th Edition

ISBN:9781305970939

Author:Braja M. Das, Khaled Sobhan

Publisher:Braja M. Das, Khaled Sobhan

Chapter12: Shear Strength Of Soil

Section: Chapter Questions

Problem 12.18P

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Table 1 given below presents the results of a conventional oedometer consolidation test conducted on a saturated clay sample with an initial height (thickness) and void ratio of H, = 20 mm and e, = 0.866, respectively. (a) Plot the consolidation curve in the semi-logarithmic space of void ratio and effective stress (or e-logo'). Determine the compression index C., recompression index C, and swell/rebound index C,. (b) Determine the past maximum effective stress (or pre-consolidation pressure) using the (maximum curvature) graphical method. (c) Determine the coefficient of compressibility m, for each of the loading/unloading stages. (d) Using the data provided in Table 2, which shows the relationship between displacement and time for the loading stage 160 kPa → 320 kPa, determine the coefficient of consolidation C, (using both methods discussed in the class) and the coefficient of permeability k for this loading stage. Table 2 Time, t (min) | Displacement, d (mm) Table 1 0.389 0.10…
5. A consolidated, undrained triaxial test is being caried out on a normally consolidated clay where c = 0 and 41= 26'. The triaxial specimen was consolidated under a cell pressure of 300 kPa and backpressure of 80 kPa. Skempton's A parameter at failure is estimated to be 0.80. The drainage valve has since been dosed and the vertical deviator stress increased to failure. What would be the deviator stress and pore water pressure at failure?
In the laboratory test on a clay sample of thickness 25mm, drained at top only, 50% consolidation occurred in 11 minutes. Assume = 0.197, T = 0.405. Find the time required for the corresponding clay layer in the field of 3m thick and drained at top and bottom to undergo 50% consolidation. Also, find the time required to undergo 70% consolidation. TE %3D 70 50
Example 9.2: A clay soil, tested in a consolidometer, showed a decrease in void res •m 1.20 to 1.10 when the presure was increased from 0.25 to 0.50 kgflem?. Calculate to. efficient of compressibility (a) and the coefficient of volume compressibility (m). If t •ficient of consolidation (c,) determined in the test for the given stress increment u m?/year, calculate the coefficient of permeability in cm/s. If the sample tested at the site was taken from a clay layer 3.0 m in thickness, determin consolidation settlement resulting from the given stress increment. lution:
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