| The p-y curve ,recommended by API code ,is obtained by homogeneous soil without considering the interaction of layer soil .Based on the flexible pile, Georgiadis proposed to the equivalent depth method to correct the p-y curve, the equivalent depth method extends the p-y curve of homogeneous soil into the layer soil. In order to research the applicability of p-y curve and equivalent depth approach to large diameter monopile under layer soil, the p-y curve, horizontal load-displacement curve, displacement and bending moment of 6m diameter monopile under four typical geological conditions: layer sand, sand-clay-sand, layer clay and clay-sand-clay are calculated by L-pile. And compared with the results of ABAQUS’s three-dimensional finite element model of monopile foundation. It is demonstrated that the effect of the equivalent depth approach is limited for the layer sand and obviously for the layer clay. For the layer soil in which a weak soil layer is located between two stronger layers, the equivalent depth method’s influence is significant and results are closer to the FEM result under big horizontal force. In the layer soil, the p-y curve overestimates the initial stiffness and underestimates the ultimate resistance of sand for the large diameter monopile,for the clay, the p-y curve underestimates the initial stiffness and the ultimate resistance. |
