(12 marks) (a) In a triaxial test for sand (c) the stress increment (s)-2.5o. What is the angle of internal frictica (o (b) A consolidated undrained (CU) triaxial test was performed on two samples of a clay and the results are: Test No. Cell pressure (kNm) Devilo stress ( km) Pore water pressure (kN) G; 1 150 500 220 (i) The Mohe circles and the failure line in terms effective stresses are drwn as shown in the figure below. List the steps followed and the calculations done in der to draw the circle (No need to draw the circle) From the figure below, find the show strength parameters in terms of effective stresse. Gui) From the figure below and for Test2: What is the neemal stress and shear stress at failure on failure plane lost? (iv) If a third test was performed on an identical sample with o'y-300 kPa, what would be the normal stress and shear stress at failure on failure planet. By the aid of sketch show how can you answer this is the steps to be followed. No need to draw a circle 400 350 300 250 200 (kPa) 150 100 0 50 100 150 200 250 300 350 400 450 500 550 600 700 750 800 ol' (kPa)