Triaxial compression tests were run on specimens from a large undisturbed block sample of clay. Data are given below. Tests 1 through 4 were run so slowly that complete drainage may be assumed. In tests 5 through 8, no drainage was permitted. Plot the Mohr failure envelopes for this soil. Determine the Mohr-Coulomb strength parameters in terms of both total and effective stresses. (After Taylor, 1948.)?

Test No.: 3 4 5 37 331 6. (, o3),, kPa oy, kPa 246 447 167 95 155 133 119 89 36 231 481 53 131 e, kPa en