Radial expansion of cylindrical cavities in sandy soils: application to pressuremeter test

Abstract

A solution for radial expansion of cylindrical cavities in sandy soils is presented. This solution is founded in a rigid-plastic model, but not perfectly-plastic, and it is valid even for large deformations (finite strains). Its application to pressuremeter test is made using the similarity principie among cylindrical cavities together with a numerical/graphical technique to solve Palmer's equation, already published by the author. Two examples are presented. The computations are made by program ANABELA II. It is verified that this solution allows to obtain the curve of the mobilized friction angles at each step of the test deformation. The importance of knowing the volumetric deformations associated to the shear is showed, as well as the differences in the mobilized friction angles curves, when finite or infinitesimal strains are used. Finally, it is discussed the value of the mobilized angle at the critical voids ratio. An attempt to compute its value, using the presented theory, is made.