Following are the results of a laboratory consolidation test on a sample of undisturbed clay obtained from the field.
Pressure, σ' (kg/cm2) Final height of specimen (cm)
0..............................................2.540
0.5............................................2.519
1.0................................................2.5
2.0............................................2.428
4.0............................................2.322
8.0............................................2.206
16.0............................................2.09
The height of the specimen at the beginning of the test was 25.4 mm, and the diameter was 63.5 mm. The moist specimen weighed 140 g and the water content was determined to be 19%. Estimate the compression index and the preconsolidation pressure from the e-log σ' curve. Given: Gs = 2.7.