新型多筒桩靴基础贯入过程有限元分析

Numerical Analysis of Penetration of Novel Multi-Buckets Spudcan

为探究自升式海洋钻井平台安装中新型的桩靴基础形式的结构影响,本文用CEL模拟方法对3种不同形式桩靴基础在贯入海底地基的过程进行模拟,结果表明:在桩靴基础的竖向贯入阻力上,贯入2倍桩靴直径深度时单筒型桩靴为传统型桩靴的1.89倍,新型多筒桩靴基础的承载力略高于传统型且更稳定。贯入过程中单筒型桩靴和新型多筒桩靴的下方筒型结构产生了更多土塞区域,从而形成大于传统型桩靴的土体位移竖向集中,有更优的工程理论表现。等效塑性应变云图表明3种桩靴基础在水平方向上的土体影响范围约为桩靴直径1.86倍,在竖直方向上新型多筒桩靴和单筒型桩靴较传统型桩靴挤压效应更明显;最大塑性应变处均在桩靴四周边缘,新型多筒桩靴和传统型桩靴有相似的挤压土体方向角度。

In order to explore the structural influence of the form of novel spudcans in jack up rigs installation, the CEL method is used to simulate the process of three spudcans penetrating into the subsea foundation. On the vertical bearing capacity of spudcan, single-bucket spudcan is 1.89 times of general spudcan when penetration depth is 2 times of spudcan diameter, and the bearing capacity of novel multi-buckets spudcan is slightly higher and more stable than general spudcan. The bucket structures of single-bucket spudcan and novel multi-buckets spudcan generate more soil plug areas during penetration, which results in vertical concentration of displacement of soil body larger than general spudcan, and has better engineering theoretical performance. The equivalent plastic contours indicate that the soil affected by the three types of pile shoe foundations in the horizontal direction is about 1.86 times the diameter of the pile shoe, and the new multi-buckets spudcan and single-bucket spudcan in the vertical direction are more obvious than the general spudcan squeezing effect. The maximum plastic strain is around the edge of spudcan, and the novel multi-buckets spudcan and general spudcan have similar compression direction angles.