Effects on small-strain dynamic shear modulus from resonant column testing

The dynamic shear modulus at very small strains (Go) and the damping properties are part of the essential parameters to analyze the dynamic response of the soils, therefore, the accuracy in finding these values is of great relevance. The influence of matric suction, capillary forces and partial saturation condition in these parameters is a relatively little studied topic, since for decades the saturated or “dry” conditions of the materials have been implemented in tests assuming an ideal conditions and conservative scenarios, as opposed to the actual insitu conditions in many soil deposits. Through a general review of the specialized literature, this article aims to present a comparative critical analysis of several tests developed with the resonant column system, in order to highlight the effects of the partial saturation condition and the matrix suction in the shear modulus (Go). It was found that the modulus has a ratio of proportionality with the magnitude of matric suction and net confining stress, that relationship, although independent of the type of material, is related to the texture and particle size characteristic.