08.66 Surface Shear Test Apparatus

In many land-use systems worldwide soil deformation is a major problem arising from increasing land-use intensity. Altered soil functions, in particular, reduced hydraulic conductivities and impeded aeration, influence the topsoil layers. This has an important effect on vulnerability to erosion, in particular. Assessing very thin soil layers like soil crusts requires very sensitive and highly accurate equipment which should also allow very small vertical stress application during measurement. Many different shear test devices are available for measuring shear strength, including direct shear apparatus, shear vanes or cone penetrometers, but the construction of the frame shear test requires a thickness of the sample of at least 3 cm for example, which excludes such a test device for soil crust strength determination.