Large-scale interface shear testing of sandbag dyke materials

This paper presents results of large-scale direct shear testing of six interfaces with materials used to construct sandbag dykes for flood protection structures. Two additional test series using intact sandbags were also conducted to examine the influence of sandbag-to-sandbag interaction in typical stacked sandbag dyke construction and sandbag-to-sod ( grass) contact representing the interface condition at the dyke foundation. The interface test results are summarised using Mohr - Coulomb shear strength parameters and interface shear stiffness parameters. The data presented in this paper are necessary for stability analyses of instrumented and monitored sandbag dyke structures that are currently under way as part of the development of a new guidance document for the design of sandbag dykes for temporary flood protection works in Canada.