INFLUENCE OF BEARING LAYER THICKNESS ON VERTICAL BEARING CAPACITY OF PILE AND SOIL DEFORMATION BEHAVIOR

Abstract

 It is considered that the soft layer under the support layer affects the vertical bearing capacity of the pile when the pile is supported by a thin layer with small support layer thickness below the tip of the pile. It is therefore important to understand the influence of bearing layer thickness on the vertical bearing capacity of pile and ground deformation in order to clarify the bearing mechanism of pile supported by a thin layer. In this study, the model ground with different support layer thickness was prepared, and the indentation test and X-ray CT imaging were carried out under an isotropic confining pressure. The influence of the different support layer thickness on the vertical bearing capacity of the pile was examined from the viewpoint of the ground displacement and strain distributions calculated by a digital image correlation method. It was found that when the thickness of the support layer was three times the pile diameter, the ground deformation during the pile indentation was almost limited to the inside of the support layer. On the other hand, when the thickness of the support layer was the same as the pile diameter, the vertical bearing capacity was lowered by extending the ground deformation to the soft layer from the early stage of the indentation.