A simplified method for predicting failure of sands under general cyclic simple shear loading

This paper describes a simplified approach based on constant volume cyclic simple shear tests with uniform sinusoidal loading that can predict failure of dry sands under general shear stress time histories. The simplified method is based on the cumulative energy hypothesis that states that the dissipated energy required by a sand sample to reach failure depends only on its initial state (Dr and σ’vo) and is independent of the characteristics of the cyclic loading applied. The proposed method uses a sand-specific multivariable regression developed using a small number of cyclic simple shear tests involving uniform sinusoidal loading without the need for advanced general cyclic loading tests. Furthermore, the regression requires only a small dataset involving one uniform cyclic simple shear test per sample initial state. The simplified method was evaluated using two comprehensive experimental studies involving two different test sands. The first dataset is an experimental program by the authors involving 20/30 Ottawa sand subjected to different cyclic loading types. The second dataset is an independent experimental program that used 0/30 Monterey sand. In both cases the simplified approach was found to yield reasonable predictions of failure of the test sands when subjected to complex and irregular shear stress loading.