A standard Proctor test was conducted on a silty clay soil collected from a proposed construction site. The results are shown in the following table. Moisture content (%) Trial no. Mass of moist soil in the mold (g) 1 1689 12.7 2 1752 15.0 1800 17.8 4 1845 20.6 5 1844 23.8 a. Determine the maximum dry density (kg/m³) of compaction and the op- timum moisture content. Given: Mold volume = 943.3 cm³. b. If specification calls for 99% relative compaction in the field, what w be the field dry density and the range of acceptable moisture content?

The properties of seven different clayey soils are shown below (Skempton and Northey, 1952). Investigate the relationship between the strength and plasticity characteristics by performing the following tasks: a. Estimate the plasticity index for each soil using Skemptons definition of activity [Eq. (4.28)]. b. Estimate the probable mineral composition of the clay soils based on PI and A (use Table 4.3) c. Sensitivity (St) refers to the loss of strength when the soil is remolded or disturbed. It is defined as the ratio of the undisturbed strength (f-undisturbed) to the remolded strength (f-remolded)) at the same moisture content [Eq. (12.49)]. From the given data, estimate f-remolded for the clay soils. d. Plot the variations of undisturbed and remolded shear strengths with the activity, A, and explain the observed behavior.

Refer to Problem 2.C.1. Results of the sieve analysis for Soils A, B, and C are given below. To obtain a more representative sample for further geotechnical testing, a ternary blend is created by uniformly mixing 8000 kg of each soil. Answer the following questions. a. If a sieve analysis is conducted on the mixture using the same set of sieves as shown above, compute the mass retained (as a percentage) and cumulative percent passing in each sieve. b. What would be the uniformity coefficient (Cu) and the coefficient of gradation (Cc) of the mixture?