a) Explain the need for soil compaction. Discuss the mechanism of com…

Previous year question for Geotechnical Engineering.

Question

a) Explain the need for soil compaction. Discuss the mechanism of compaction in cohesionless and cohesive soils.

b) A Standard Proctor Test on a soil gave the following results:

Trial 1: Water Content (%) = 10.2, Wet Density ($g/cc$) = 1.82

Trial 2: Water Content (%) = 12.5, Wet Density ($g/cc$) = 1.94

Trial 3: Water Content (%) = 14.3, Wet Density ($g/cc$) = 2.02

Trial 4: Water Content (%) = 16.1, Wet Density ($g/cc$) = 2.00

Trial 5: Water Content (%) = 18.4, Wet Density ($g/cc$) = 1.95

i) Compute the dry density for each trial.

ii) Plot the compaction curve (dry density vs water content).

iii) Determine the Optimum Moisture Content (OMC) and Maximum Dry Density (MDD).

iv) Comment on compaction behavior of the soil.