The pressure versus void ratio data determined from a consolidation test on an undisturbed clay specimen is as follows:

(a) Plot the pressure versus void ratio curve on both arithmetic and semi-logarithmic graphs.

(b) Determine the equations for the virgin compression curve and for the rebound curve for unloading, starting at 1280 kPa.

(c) What are the corresponding modified compression and recompression indices for this soil? 

(d) Estimate the stress to which this clay has been pre-consolidated. (After A. Casagrande)?

Transcribed Image Text:

Void Ratio Void Ratio Pressure (kPa) Pressure (kPa) 20 40 1280 320 0.602 0.864 0.853 0.628 0.843 80 80 20 0.663 160 0.830 0.704 0.801 320 0.785 640 0.696