CVE20004 Civil Engineering|Consolidation Test

CVE20004 Civil Engineering|Consolidation Test
Required Calculations
1. Determine the sample thickness for each loading (i.e. starting from Hfinal = 15.26 mm at 800 kPa).
2. Calculate the void ratio of the sample at the end of consolidation test (i.e. efinal when loaded at 800 kPa). Assume Gs = 2.65.
3. Calculate the void ratio for each equivalent load. Hint: you can calculate these values back from 800 kPa using the formula: Δe = ΔH(1+e0)/H0. Or you can convert the measured displacements into volume increments and calculate the void ratios directly through simple phase relationships. I recommend calculating the void ratios both ways to enable self-checking of your answer.
4. Plot the void ratio vs. pressure data using a linear scale to determine the coefficient of volume compressibility (mv) for each load cycle.
5. Plot the void ratio vs. pressure data using a log scale to determine the compression indices (cc and cs). Also determine the pre-consolidation pressure of the sample using the simple method and Casagrande’s method.
6. Plot the settlement (sample deformation) vs. time using a log scale for one load cycle only, and calculate the coefficient of consolidation (cv) using Casagrande’s logarithm of time method. It doesn’t matter which load cycle you choose.
7. Plot settlement (sample deformation) vs. square root of time for the same load cycle above, and calculate the coefficient of consolidation (cv) using Taylor’s square root of time method. Compare this result to the one using Casagrande’s logarithm of time method and provide a brief comment.
8. Summarise all of the above results in a clear (easy to read) table.
9. Knowing that the soil sample was retrieved from a depth of 2 m, state whether the clay sample tested is considered to be a normally consolidated soil or an over consolidated soil.
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