EXPERIMENTAL STUDY ON PERMEABILITY AND SETTLEMENT OF SATURATED SAND UNDER IMPACT LOADING
冲击载荷下饱和砂土渗流和破坏的实验研究

An experimental study on the deformation and filtration of saturated sands underimpact loading is carried out by examining the behavior of a saturated sand column dropping tothe ground. The longitudinal drainage pathways and horizontal cracks in the skeleton of saturatedsands are discovered. By means of analyzing the images, the phenomena (Occurring in sand sampleNo.1) can be summarized as follows: (1) Some horizontal cracks cross the full sections, generally, thenumber of these cracks is three. Some small horizontal cracks non-crossing full sections occur alsoin sometimes. The total number of the cracks is not more than six. (2) The interval between twocracks is 2~3cm. (3) The time is about 20 s when the cracks appear. The cracks can last severaltens seconds. (4) The seepage of saturated sand after impact-induced liquefaction is nonuniform.The longitudinal drainage pathways occur at about 10 s. The radiuses of the longitudinal drainagepathways airs difference. The maximum drainage pathway occurs in the center of the sand column.The factos which may affect these phenomena are studied by means of comparative experiments,such las changing. drop-height, or Changing the distribution of 'sand samples. At last, a qualitativeexplanation of the above phenomena is proposed.