Abstract
A series of centrifuge model tests was performed in order to study the failure chracteristics of a dry sand around a deep circular shaft at the active state. Finite element analysis based on elasto-plastic model was also conducted for comparison with the experimental results. Discusion was the relationship between the failure mechanisms and the active earth pressure distributions of the shaft. It was found that the failure mechanisms of the circular shaft showed three dimensional nature and were strongly affected by the depth of ground (;stress level), resulting in different active earth pressure distributions of the shaft.