A Statistical Study of Shear Modulus Determination by In-situ Shear Wave Velocity and Dynamic/Static Triaxial Tests

This paper is a statistical study of the variation of shear modulus over a wide range of strain with the objective of providing a basis of nonlinear modulus estimation for settlement analysis in alternating layers of cohesive and sandy/gravelly soils in Beijing. In order to overcome the difficulty of obtaining reliable stress-strain data from routine triaxial tests when the strains are very small, this study is based upon an unified treatment of dynamic and static stress-strain behavior utilizing the data of in-situ shear wave velocity and dynamic/static triaxial tests conducted in parallel. A broken line relationship on a log-log plot is adopted for simplicity and convenience to approximate shear modulus changes over a wide range of strain and another exponential rule is employed to take account of the effect of the lateral confining pressure. Some basic trends of nonlinear deformation of soils as evidenced by this statistical study have also been summarized.