Reference threshold shear strain of soil. Its application to obtain an unique strain-dependent shear modulus curve for soil

The purpose of this paper is to investigate the shear modulus degradation of soil. The study is based on a key parameter defined previously by the authors and called reference threshold shear strain. This parameter is defined as the shear strain for a stiffness degradation factor of G/G(0)=0.7, in which G(0) is the very small strain shear modulus and G the secant shear modulus. The influence of some important factors on the reference threshold shear strain is discussed in this paper. Based on a previous proposed normalisation methodology it is possible to define some unified relationships that allow the assessment of shear modulus degradation of soil.