DEM Analysis and Prediction for the Lateral Interaction of Monopile in Gravel Soil

Gravel is a common geotechnical material in civil engineering. To investigate the lateral bearing behavior of monopile in gravel materials and deeply understand the microscopic mechanisms, parametric three-dimensional discrete element analyses are performed to study the lateral interaction between the single pile and gravel. First, using the experimental data of two typical gravel samples, the discrete element methods (DEM) for monopile in gravel materials are investigated. A discrete particle flow model of pile segments that allows for the construction of p–y curves at various depths is proposed. The lateral mechanical behaviors (p–y curves) between monopile and different gravel material are then studied. The effects of gravel porosity, distribution and grain-size on both the strength and shape of the p–y curves are investigated. The results show that the influences of porosity and depth on the p–y behaviors of gravel are significantly different from those of sand. Furthermore, the obvious differences in p–y behaviors between the coarse gravel and fine sand are the effects of grain size and size distribution. Based on these results, corresponding equations for the estimation of the p–y curves are proposed and further validated by independent field test data. It is concluded that the proposed p–y curve is capable of modeling both different grain sizes and size distributions in gravel-monopile interaction analyses during lateral loading.