Question 2 The results of a standard compaction test on a soil (G; = 2.7) are as shown in the table below. w(%) xkN/m³) 16.9 6.8 8.1 9.8 11.5 13.2 15 17 18.5 19.5 20.5 20.1 19.2 18 (a) Using excel, plot the compaction curve. Submit your excel file with your exam solution (b) Plot the ZAV curve for the appropriate water content and dry density range (c) Construct the 80 % and 90% saturation lines (d) Determine the maximum dry unit weight and optimum water content (e) Determine the degree of saturation at the maximum dry density

The grain-size characteristics of a soil are given in the following table. a. Draw the grain-size distribution curve. b. Determine the percentages of gravel, sand, silt, and clay according to the MIT system. c. Repeat Part b using the USDA system. d. Repeat Part b using the AASHTO system.

Repeat Problem 2.14 with the following values: Gs = 2.75, temperature of water = 21C, t = 88 min, and L = 11.7 cm. 2.14 A hydrometer test has the following result: Gs = 2.65, temperature of water = 26 C, and L = 10.4 cm at 45 minutes after the start of sedimentation (see Figure 2.25). What is the diameter D of the smallest-size particles that have settled beyond the zone of measurement at that time (that is, t = 45 min)? Figure 2.25 ASTM 152H type of hydrometer placed inside the sedimentation cylinder (Courtesy of Khaled Sobhan, Florida Atlantic University, Boca Raton, Florida)

Redo Problem 2.7 according to the AASHTO system (Table 2.3). 2.7 The particle characteristics of a soil are given below. Draw the particle-size distribution curve and find the percentages of gravel, sand, silt, and clay according to the MIT system (Table 2.3).

A hydrometer test has the following result: Gs = 2.65, temperature of water = 26 C, and L = 10.4 cm at 45 minutes after the start of sedimentation (see Figure 2.25). What is the diameter D of the smallest-size particles that have settled beyond the zone of measurement at that time (that is, t = 45 min)? Figure 2.25 ASTM 152H type of hydrometer placed inside the sedimentation cylinder (Courtesy of Khaled Sobhan, Florida Atlantic University, Boca Raton, Florida)

The particle characteristics of a soil are given below. Draw the particle-size distribution curve and find the percentages of gravel, sand, silt, and clay according to the MIT system (Table 2.3).

Refer to the soil in Problem 4.5. Using the Casagrande plasticity chart, graphically estimate the shrinkage limit of the soil as shown in Figure 4.22. 4.5 The following data were obtained by conducting liquid limit and plastic limit tests on a soil collected from the site. Liquid limit tests: Plastic limit test: PL = 19.3% a. Draw the flow curve and determine the liquid limit. b. Using the Casagrande plasticity chart (Figure 4.21), determine the soil type.

Since laboratory or field experiments are generally expensive and time consuming, geotechnical engineers often have to rely on empirical relationships to predict design parameters. Section 6.6 presents such relationships for predicting optimum moisture content and maximum dry unit weight. Let us use some of these equations and compare our results with known experimental data. The following table presents the results from laboratory compaction tests conducted on a wide range of fine-grained soils using various compactive efforts (E). Based on the soil data given in the table, determine the optimum moisture content and maximum dry unit weight using the empirical relationships presented in Section 6.6. a. Use the Osman et al. (2008) method [Eqs. (6.15) through (6.18)]. b. Use the Gurtug and Sridharan (2004) method [Eqs. (6.13) and (6.14)]. c. Use the Matteo et al. (2009) method [Eqs. (6.19) and (6.20)]. d. Plot the calculated wopt against the experimental wopt, and the calculated d(max) with the experimental d(max). Draw a 45 line of equality on each plot. e. Comment on the predictive capabilities of various methods. What can you say about the inherent nature of empirical models?

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.

How is the plasticity index of a soil determined?