Simple shear tests with a varying shearing direction during cyclic shearing

Tests with cyclic lateral loading on a pile have shown that the pile reacts to a change of loading direction with increasing accumulation of lateral displacements. This phenomenon is known as ‘pile drift’. To investigate this behaviour at small scale under laboratory conditions, a specifically designed simple shear apparatus with two shearing axes was developed. This paper presents the first results from tests with this apparatus. The first test series consisted of monotonic tests with different densities and cyclic tests on dense sand with varying load level and varying angle of loading ψ. The cyclic tests showed an increased accumulation of shear strain if the shearing direction varied during cyclic shearing.