Effect of aspect ratio on soil failure pattern generated by vertical flat tines at low strain rates in dry sand

Abstract

Soil failure patterns were studied under the action of flat vertical tines operating under quasi-static conditions in dry compact sand. The soil failure was found to be by progressive shear, starting horizontally from the lower tip of the tine and then progressing upward towards the horizontal soil surface. No soil compression below the shear line was observed. The shear angle was found to be 27 ± 2 °, very close to the theoretical angle (π/4 − φ/2) of 26·5 ° for all tools studied. With increase in tine depth, even at the same aspect ratio, the additional shearing within already failed zones of soil became more and more prominent. The observed soil failure pattern was found to be different from the inclined shear planes assumed in classical soil mechanics theory.