Abstract
When 2-dimensional seepage flow experiments along/below a vertical sheet pile were made using sandy soils in laboratory, it was observed that a lot of air bubbles were formed in the sand during the seepage process. Those air bubbles were also observed to trigger a progressive failure of the sand deposits around the sheet pile. A series of seepage tests are again carried out by changing the degree of saturation of seepage water with dissolved air, and the mechanism of the air bubble formation in saturated sand that should happen with time under seepage flow application was found due to over-saturation of seepage water with air. Although the extent of the bubble formation depends on hydraulic gradient, confining pressure and grain size distribution of sand, those air bubbles may cause progressive failure of sands under even low seepage force.
