Abstrait

Parameters Influencing Dynamic Soil Properties: A Review Treatise

Shiv Shankar Kumar, A. Murali Krishna, Arindam Dey

Determination of dynamic soil properties is a critical task but an extremely important aspect in geotechnical earthquake engineering problems. Dynamic soil properties include shear modulus, modulus reduction and damping variations with cyclic strains. Field evaluation of dynamic soil properties predominantly aids in the estimation of the shear modulus/shear wave velocity at low strain level. Laboratory based evaluations helps in the estimation of a realistic range of dynamic soil properties (e.g. experiments carried out in a specific strain-controlled environment) at varying strain levels. Factually, the cyclic triaxial method has been the most widely used to measure the strength, deformation and dynamic characteristics of soils. Such experiments can also help to simulate and comprehend the liquefaction characteristics and evaluate the liquefaction potential of the concerned medium. Various parameters like: relative density, confining pressure, soil plasticity, strain amplitude, frequency and magnitude of cyclic loading influence dynamic soil properties. This paper presents a review on the dynamic soil properties and their influencing parameters. Earlier studies on dynamic soil properties are presented systematically to highlight the importance of the each influencing parameter. Subjected to similar testing conditions, a significant difference in the dynamic soil properties for characteristically different soils have been observed by earlier researchers. It has been observed that the dynamic soil properties are affected by many factors like: method of sample preparation in the laboratory (whether intact and reconstituted samples), relative density, confining pressure, methods of loading, overconsolidation ratio, loading frequency, soil plasticity, percentage of fines and soil type.