Small strain stiffness of soils and methods of its measurement

This thesis consists of theoretical and practical part. Firstly, the soil behaviour at small-strain range and its physical nature are described. Subsequently, the individual soil parameters affecting the value of small-strain shear modulus and the shape of the stiffness reduction curve with increasing shear strain are described. The individual methods of measuring the small-strain stiffness in the laboratory and in-situ with a more detailed explanation of the evaluation of measurements using bender elements are given in the last chapter of the theoretical part. In the practical part, a device for measuring small-strain stiffness using bender elements was put into operation. The used laboratory equipment is described first and then the parameters of tested soil are given. The main chapter is measurement and evaluation of the impact of software and hardware settings and the influence of effective stress of soil on the small-strain shear modulus that is compared with predictions of empirical expressions from the literature