Specific Dissipated Energy as a Failure Predictor for Uniform Sands under Constant Volume Cyclic Simple Shear Loading

An experimental study was performed to investigate the dissipated energy to failure of sand samples subjected to uniform and non-uniform cyclic simple shear loading. The hypothesis evaluated was that for a given initial sample state the specific dissipated energy required to reach failure should be reasonably constant independent of the type of stress-time history used in the testing. Test samples consisted of dry Ottawa sand prepared at nine different initial states that were subjected to different stress controlled cyclic horizontal shear loading waveforms that included 15 uniform sinusoidal waves and up to 33 non-uniform loading wave forms. The experimental program presented showed that the measured cumulative dissipated specific energy to failure, defined when the double amplitude shear strain reaches 7.5%, for the different sample initial states was reasonably constant but with coefficients of variation ranging between 13 to 44%. As expected, the cumulative dissipated energy increased with increasing initial stress level and relative density. The findings support the notion that specific dissipated energy can be used as a reasonable failure predictor for uniform dry sands based on their initial state and are independent of the type of cyclic simple shear loading waveform using in the testing.