The following data were obtained from a CU test with pore pressures measured on an undisturbed specimen of sandy silt. The consolidation pressure was 850 kPa and the specimen was sheared in axial compression.

(a) Plot curves of principal stress difference and pore pressures versus strain. Plot on one sheet.

(b) Plot the stress paths on a p-q diagram.

(c) What is the maximum effective principal stress ratio developed in this test? Is it the same as the maximum obliquity for this specimen?

(d) Is there any difference in ∅' as determined when the principal stress difference or the principal effective stress ratio is a maximum? (After A. Casagrande.)?

Transcribed Image Text:

Principal Stress Difference (kPa) Induced Pore Pressure (kPa) Strain (%) 226 0.11 81 415 0.25 187 0,54 697 323 968 0.99 400 1470 2.20 360 2060 3.74 219 2820 5.78 -009 -281 -530 -703 -767 -789 3590 8.41 4160 11.18 13.93 16.82 4430 4310 4210 19.71