Triaxial set-up and procedure to investigate the shear strength of gassy sediment

In the marine realm, small amounts of gas (Sr > 80%) are almost always present in the sediment. Beyond this, gassy soils also occur in coastal areas and is relevant in a number of coastal engineering applications such as dyke and offshore wind energy plant foundations. Gas has been reported to significantly reduce the shear strengths of the host soils. In order to investigate the effect of enclosed gas bubbles on the mechanical behaviour of soils, a triaxial set-up and experimental procedure was designed based on the axistranslation technique for gassy soils. The procedure allows the non-destructive manufacturing of granular and fine-grained soil samples with a homogeneous distribution of gas bubbles. Thereby, a measurement and monitoring approach that allows the precise adjustment of the degree of saturation within the soil sample at the beginning of the shear phase is implemented. The experimental data generated by this procedure is a further step towards understanding this essential soil mechanical phenomena.