Investigation into Sand Movement around a Column Using a Wind Tunnel
摘要
In the present study, sand movement around a column was investigated in the laboratory using a wind tunnel and a high-speed digital video camera. The thickness of the sand layer in the test section was kept at 0.28 m. It was observed that the sand from upstream and also from both sides of the obstacle (column) moved faster due to accelerated sand-driving wind compared to those particles away from the column or downstream. This caused visible erosion of the sand layers in the upstream and also from both sides of the column. These eroded sand particles were scoured deeper than those at initial horizontal surface. However, movement of the sand became steadily slower when the scoured depth increased. The scoured area around the column fanned out from the column with time. The column began to oscillate as the sand below the bottom of the column was scoured, and finally, it overturned windward. In the present investigation, the relation between the scoured depth around the column and blowing time of wind, also the relation between the depth of the buried column and the time required until the column overturned, and the mechanism of the sand movement around and below the column were clarified in detail.