Question 3: The parameters of a soil are λ = 0.26, K = 0.06, cs= 24°, v' = 0.3, eo = 1.08, p = = 280 kPa and Ro= 7. If the soil was to be loaded for a standard CU test and a standard CD test, predict the following: 1) Initial yield stresses for the standard CU and CD tests. 2) Failure stresses for the standard CU and CD tests. 3) The total deviatoric strain and porewater pressure for an increase of mean effective stress of 2 kPa after initial yield for the standard CU test.

A particular soil failed under a major principal stress of 425 kPa with a corresponding minor principal stress of 215 kPa. If for the same soil, the minor principal stress is changed to 351 kPa, determine the new normal stress on the failure plane of the soil.

Two soil sample A and Bhave porosities n₁ = 40% and ng = 60% respectively. What is the ratio of void ratios e: eg? A (a) 2:3 (c) 4:9 (b) 3:2 (d) 9:4

6. ( A silty sand sample failed during a consolidated-undrained triaxial test at o,=280 kPa and 0,=170 kPa. With the assumption that c=0 and A=0.65, determine the consolidated-undrained friction angle de and a drained friction angle o. If a consolidated-undrained test on such a soil is conducted at a confining pressure o,=340 kPa, what will be major total and effective stresses and the pore water pressure at failure? What will be the maximum shear stress t during a "slow" direct shear test, if the vertical stress o,=160 kPa? cu - 141° $' = 21.0° %3D 560 kpQ 417 197 RPa T = G1.4 RPa