Question

Question 4(Shear Strength) Note: Part a) and b) must be answered on GRAPIT PAPERI A series of conventional triaxial compression tests were conducted on three identical samples of a cohesionless soil. Test results are tabulated as follows: Sample Effective Confining Pressure, 0' (kN/m?) 198.8 347.9 280.0 Principal Stress Difference at Failure, Ag (kN/m2) 596.4 1043.7 a) Draw the Mohr's circles for the soil samples A and B in terms of effective stresses. [10 marks) b) By drawing the Mohr-Coulomb failure envelope for the soil on the same graph, determine the shear strength parameters c' and ' corresponding to those Mohr's circles. [3 marks] c) From the results of b), calculate the value of Ag for soil sample Cat failure. Then determin the stress component o, 'and t' in the failure plane of the sample C.

Answer 1

151 - 5846 illas 50 1 596.4 1043.7 198.8 347.9 280 795.2 1391.2 from mohr grale Co sings Geo To=37 dan (450+) = 2 198.8 347 9 795.2 1391.2 (C) for soil comple of 5 53 tan? (45+ 8) = 26 ton (45+2) G - 280X (202 + 0 6 - 120 kwileme 05 - 5,53 = 1180-280 Jo5 = 240 kilme 6 - 057753) + 5-5, 60520 + Cry 3020, T = 15-5 ) sino Gn - ( 120+280) + (120-200 x Cos 2/45+84) Ton - 448 kilom t . Tz = 336 km2 Ne Cryo 1120-280 ron (go+37) 2