Sandbanks soils are under research in situ. Sand massif response to ultrasound impulse, shock and vibro action is investigated. In all experiments mechanisms of dilatation of dense sand is source of sharp responses non-linearity. From laboratory experiments most interesting is observation of dilatation in the sandy sample under growing with constant velocity loading and heaping experiments on vibro table. Sea sand under action of wind and water waves in situ is observed. Ripples represent the self-organized formations. Covering sandy fields, they counteract ablation of sand and promote self-preservation of a sand massif by lowering velocity of a wind above the surface. As show analysis and observation, similarity of granules played important role in processes of self-preservation and self-organizing. In laboratory experiments directly are not observed self-organizing, but considering them together with results of experiments on vibro table, it is possible to assume connection on of vibrations in the nature and ripple forming. In all researches non linearity of marine sand response is shown distinctly and vibro dilatation is the fundamental mechanism of non linearity.
展开▼
