Pressuremeter Test and Disturbance Effects

Abstract

The effect of Poisson's ratio on the disturbance index is considered by obtaining solutions to expansion of cylindrical cavities in layered elastic system. For a specific size of the remolded annulus, the disturbance index becomes lower as the disturbance becomes smaller and Poisson's ratio becomes larger, and it decreases much faster with decreasing disturbance than with increasing Poisson's ratio. Also, for a specific value of Poisson's ratio, the rate of decrease of the disturbance index with decreasing disturbance is much faster for a larger annulus than for a smaller one. In general, the effect of Poisson's ratio on the disturbance index is more pronounced for a small remolded annulus than for a large one and it is minimal for a very small disturbance. The results can be used to evaluate the modulus of deformation of the undisturbed soil mass from the pressuremeter test results and are presented in the form of graphs suitable for practical applications.