Behaviour of Soil Subjected to Dynamic Loads

Many geotechnical problems involve design of dynamically loaded foundations. The design criterion fr dynamically loaded foundations is often described in terms of limiting values for the displacements. The displacements in the soil are normally very small when dealing with dynamically loaded foundations, and hence it is necessary to know the deformation properties for the soil at very low strain level. The main topic of the project is to increase the knowledge of the behaviour of Danish soils at small strain levels and to extend the laboratory facilities to deal with testing at small strains. The soil behaviour at very small strain levels is non-linear, and the most common testing technique for this situation is the resonant column technique. One of the aims of this project is to install, check, get familiar with and perform tests on different kinds of Danish soils in a new Drnevich Longitudinal-Torsional Resonant Column apparatus placed at the Soil Mechanics Laboratory at Aalborg University. Another, but quite new technique for small strain testing to determine the maximum shear modulus, G_max, is the bender element technique, and as part of the project this technique has also been introduced in the laboratory.