ABSTRACT
The Self Boring Pressuremeter (SBP) test is an in-situ testing technique that evaluates mechanical properties of soils. Although as little as possible, its installation process unavoidably disturbs the original state of the surrounding soil. It is therefore important to understand the mechanism of the disturbance effects and their influence on the engineering data obtained from the subsequent pressuremeter test. This study examines the following four disturbance effects when an SBP test is conducted in heavily overconsolidated clays: underdrilling, overdrilling, instrumentation insertion, and smearing along the instrument. The Strain Path Method is adapted to simulate these disturbances. The computed strain profile for each case was used to calculate the spatial distributions of the effective stresses and excess pore pressures in the soil around the instrument. The computed values were then used as the initial state of the pressuremeter test. By analyzing the subsequent testing curves, the magnitudes of disturbance caused by the installation process were quantified. Some practical implications which help evaluate the engineering properties from disturbed pressuremeter test data are given.
