Laboratory pressuremeter tests on reconstituted sill samples

The differences in pressuremeter strength parameters obtained from the various interpretation procedures are often attributed to the soil disturbance associated with the pressuremeter installation techniques. The results of an experimental investigation on the effect of pressuremeter expansion rate and drainage conditions upon a low plasticity cohesionless inorganic silt are presented. To avoid any soil disturbance prior to shearing, soil sample are reconstituted, in a large laboratory calibration chamber, from a sill slurry, around the pressuremeter probe. Different interpretation techniques of pressuremeter data are used. Estimated pressuremeter parameters, particularly the lift-off pressure and the peak strength, are found very sensitive to the interpretation method. Loading rate as fast as 10 minutes to double the initial volume of the probe is found not fast enough to prevent drainage.