The use of a field open-sided direct shear box for the determination of the shear strength of shallow residual and colluvial soils on hillslopes in the south Pennines, Derbyshire.

Engineering drawings are provided for a field open-sided direct shear box with a basal shearing area of 300mm x 300mm and two 300mm x 150mm side shearing areas, following the design of Chandler et al. (1981). Lead blocks are used to provide normal loads simulating natural geostatic pressures and a shearing force is provided by a winch/cable system. The field open-sided direct shear box was used to determine the effective angle of shearing resistance and the effective cohesion of shallow residual and colluvial soils on hillslopes in the south Pennines, Derbyshire. The field open-sided direct shear box is appropriate for determining the effective shear strength of shallow residual and colluvial soils on hillslopes as it incorporates the pedogenic and biogenic structural discontinuities and compositional inhomogeneities which are not represented adequately in standard laboratory direct shear strength and other conventional in situ field shear strength testing apparatus.