Shear Modulus and Damping Ratio for Normally Consolidated Peat and Organic Clay in Hokkaido Area

This paper presents that the shear modulus at small strain (G₀) for peat and organic clay in normally consolidated state, as well as the strain dependence of the shear modulus and the damping ratio (dynamic property). In analyzing dynamic ground behavior, G₀ and dynamic property of soils should be accurately determined. Therefore, eight types of peat and two types of organic clay, which were all different in terms of engineering property, were given a series of cyclic torsional shear tests in the normally consolidated state, to clarify effects of physical properties of the soils and effective confining pressure on G₀ and dynamic properties. Finally, based on the test results, empirical equations to determine G₀ and dynamic property of peat and organic clay are proposed.