Question

1. The following results were obtained at failure in a series of drained triaxial tests on fully saturated clay specimens originally 38 mm diameter by 76 mm long. The minor and major principal stresses are calculated and presented in the table below (You are responsible of learning this procedure for the MT exam). All-round pressure (kN/m²) Axial compression (mm) Axial load (N) Volume change (ml) 200 7.22 480 5.25 400 8.36 895 600 9.41 1300 9.30 7.4 (a) Determine the values of the shear strength parameters c' and op'. (b) A different specimen of the same soil is tested in undrained triaxial compression at a cell pressure of 240 kN/m² and fails when the deviator stress is 160 kN/m. Calculate the pore water pressure in the specimen at failure. Ao= 11.34 cm?V=43.07 cm Axial Load, P ΔΗ &=AH/H, (mm) &= AV/VA AV (cm ) (N) (cm²) (o', '3)=P/A (kPa) O (kPa) (kPa) Center Radius (o',+O3)/2 10,-63)/2 480 7.22 0.10 5.25 0.12 11.00 436 200 636 418 218 895 0.11 7.4 848 400 1248 824 424 8.36 9.41 0.17 0.22 10.55 10.14 1300 0.12 9.3 1282 600 1882 1241 641

Answer 1

Solution Now, To Determine the initial area; to - Ide (28) - 1134.11 mm To Determine the initial volume Vo = tolo = 1134.11 x 76 - 86 192.36 mm3 To Determine the corrected area А Ao A = A - AL I-E 1134.1 - 7.22 76 = (253-16 mm? the stress, To Determine P 5,- co to I-E - 490.86 Km m2

C 3 U50.86 = 480.86 + 200 = 650.86 kN/me Now, calculate for other valves. KN KN toad Al (mm) (A) E=Allo AC (mm) m2 - az 650.86 200 7.22 565 0.095 1253.16 450.86 400 8.36 2015 1196.53 on 1874.28 196.5 600 9.411321 0.124 1294.65 1020.35 1620:35 c'- 20 kalo 200 yoo do 600 (obo 16 po . The parameters c'= 20 km 9 - 36