A set of triaxial tests have been conducted for clays from a slope shown in Figure 1 with different initial cell pressures. The results of triaxial tests are shown in Table 1. Tests 1 and 2 are for soils above ABE line while Tests 3 and 4 are for soils below ABE. A Part I: 1. B 71.5 37 C 275 m Centroid TEST 1 2 3 4 Figure 1 Geometry of a clayey slope and triaxial test Table 1 Triaxial test results , (KPA) 100 200 100 200 Oz Oz,max (KPA) 143 243 167.5 267.5 Or Determine the values of undrained strength of the clays above and below ABE, respectively [15%]; 2. From the triaxial tests, it was found that Young's modulus and Poisson's rate for the clay above ABE are 20 MPa and 0.49, respectively. Calculate the bulk modulus and shear modulus for the clay above ABE [10% ]; 3. Draw the Mohr's circle for the stress state when the material fails in Test 1 [15%]; 4. Draw the stress element with the maximum shear stress for Test 1 [15%]; Part II: 5. In an investigation of the slope, a trial slip surface (i.e. red curve in Figure 1) is chosen in the form of a circular arc of radius 11.75 m. The area of the figure ABCDEA is 87 m and its centroid is shown. The average density of the soil is 1760 kg/m. Determine if the slope is stable using the assumed failure mode. If yes, calculate its Factor of Safety using the limit equilibrium method [30%]; 6. Discuss the advantages and disadvantages of the limit equilibrium method [15%].