A Calibration Chamber for Cohesive Soils
The paper describes the design and performance of a calibration chamber system for testing in-situ test devices in cohesive soils. Techniques for preparing “undisturbed” clay specimens from a slurry and consolidating them under zero lateral strain K0 conditions are presented. The chamber was used for strain controlled model pressurementer tests during which pore pressure was monitored. Duplicate model pressuremeter tests performed in normally consolidated (NC) kaolinite (s'vc = 276 kPa) resulted in essentially identical expansion curves. The specimens had an average water content of 44.9% and a coefficient of variation of 1.5%. Also, the predicted lateral stresses essentially coincide with those applied to the chamber specimen.