Interface behaviour of sands from constant normal stiffness direct shear tests

This paper reports an experimental study concerning the frictional behaviour of sand-solid structure interfaces. The study was performed using a constant normal stiffness (CNS ) direct shear box. Three natural silica sands and four aluminium plates with different roughnesses were investigated. A comparison between constant normal load (CNL) and CNS tests is reported. The influence of the main factors controlling the frictional behaviour of the investigated materials such as: constant normal stiffness, roughness of solid surface, sand properties and relative density, initial effective normal stress are analysed and discussed.