Centrifuge modelling of non-displacement piles on a thin bearing layer overlying a clay layer

Pile foundations constructed on thin bearing layers have been widely used in Japanese estuary regions. Although several methods for predicting the bearing capacity of the pile tip have been proposed, the relationship between the load and settlement of the pile tip, which is necessary for predicting how the foundation settle, remains under-investigated. It depends on the nonlinear characteristics and confining stress of the soil. In this study, centrifuge modeling is used to investigate the bearing behavior of non-displacement piles. Seven tests of vertical loading were conducted on model piles (fabricated at 1/50 scale with a diameter, D, of 20 mm) on a bearing layer with an effective thickness ratio, H/D, which varied from zero to eight. Based on the experimental results, a method previously proposed by RTRI (1987) for predicting the bearing capacity is validated, and a method is proposed for predicting the settlement relationship using a hyperbolic curve.