自升式平台插/拔桩阻力影响因素数值分析

Numerical analysis of pile insertion and pullout of jack-up platforms

文中通过建立数值模型,模拟真实工况,研究并讨论了自升式平台插/拔桩阻力的影响因素及机理.首先以Hossian土工离心模型试验为基础,得出土壤实际参数;其次采用CEL分析法,建立ABAQUS插/拔桩数值模型;然后以数值解为依据,讨论插桩阻力与插桩速度、土层强度比、上土层相对厚度的关系;最后研究拔桩阻力与土体弹性模量、桩靴埋深、上拔速度的影响机制.结果表明:插桩阻力与插桩速度、上土层相对厚度呈正相关关系,与土层强度比呈负相关关系;拔桩阻力与土体弹性模量、桩靴埋深、上拔速度呈正相关关系.

Through the establishment of numerical model and the simulation of real working conditions,the paper studies and discusses the impact factors and mechanism of the jack-up platform on pile insertion and pullout.Firstly,the practical parameters of soil are obtained by using the centrifuge model test of Hossian. Using CEL analysis,the numerical model of ABAQUS is established. Based on the numerical solution,the relationship between inserting resistance and the speed,the strength of the soil and the relative thickness of the upper layer are discussed. The mechanism of the influence of the pulling resistance with the elastic modulus of the soil,the depth of the spudcan and the speed of the uplift are studied. The results show that the inserting resistance is positively correlated with the speed and the relative thickness of the upper soil layer and negatively correlated with the soil depth. The pulling resistance is positively related to the elastic modulus of the soil,the depth of the spudcan and the pulling speed.