A laboratory testing campaign has been performed on soil samples within the context of a ground investigation: Geotechnical Engineering Course Work, UOL, UK

Part 1 – Laboratory testing
A laboratory testing campaign has been performed on soil samples within the context of a ground investigation that relates to the construction of a five-story building. The soil strata found in situ comprise a 6 m layer of fine-grained material overlying permeable bedrock. The groundwater table was found to be at the ground surface. Consider that 
sufficient high-quality samples were obtained using block sampling procedures within a trench from a depth of 3 m in order to complete the following task

a) A representative soil sample (356.52 g) was subject to a wet sieving test producing the following data as reported by a laboratory technician (see Table):

Plot the particle size distribution by using semi-logarithmic axes, determine the value of the mean diameter (d50), the coefficient of uniformity (cu), and the coefficient of curvature (cc), and then classify the soil and comment on the key expected geotechnical properties and behavior of such a soil. [6 marks}

c) Recall that the natural moisture of the soil is 36.4%. Consider that the following properties were also measured using the relevant experimental procedures on representative (saturated) samples of the soil deposit at a depth of 3 m:
Specific gravity, Gs = 2.62
Unit weight of water, gw = 9.81 kN/m3
Draw a phase diagram and estimate the void ratio and the bulk density of the soil. What can you comment in relation to the density of the soils and its expected compressibility? How would you expect these to vary with depth? [5 marks]

d) An oedometer test was also performed on a (saturated) reconstituted sample obtained at the site. The initial void ratio was calculated as 1.005 and the initial sample height was 20 mm. The following measurements were reported for each of
the 24-hr stress increments