﻿ 自升式钻井平台抗滑移能力分析
 舰船科学技术  2017, Vol. 39 Issue (8): 75-78 PDF

Anti-slide ability analysis of jack-ups
WU Wen-le, LIAO Tian-an, TANG Wen-xian, PENG Wei
School of Mechanical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, China
Abstract: Based on the formula, the paper simulates the process of spudcan slide in the soil, and now to construct a numerical method to analye the anti-slide force of spudcan. First of all, the paper researches the theoretical anti-slide formula from different paper, based on which, the finite element model of spudcan-soil system is built to, using CEL method and establishing the required conditions, study on the flow deformation of soil and calculate the numerical result. Finally, the theoretical result and numerical result are compared and discussed to compensate for the lack of theoretical formula and provide a accurate method to calculate the anti-slide force of spudcan.
Key words: jack-up platform     spudcan     anti slide     numerical analysis
0 引　言

1 桩靴抗滑移能力理论分析 1.1 地基土与抗滑移能力

 图 1 地基稳定曲线 Fig. 1 Stability curve of foundation soil

1.2 水平载荷理论值计算方法

 ${F_i} = 0.625{C_{si}}{C_{hi}}{V^2}{A_{pi}},$ (1)

 $F = 0.5\rho U{C_D}AdL + \rho {C_M}\pi dL/4{\text{。}}$ (2)

1.3 抗滑移能力计算方法

 ${F_H} = F + \sum {F_{Li}},$ (3)

 ${R_H} = {R_c} + {R_{cf}},{R_c} = G\tan \theta ,{R_{cf}} = {S_u}{A_{ms}}{\text{。}}$ (4)

2 桩-土系统的数值模型

Abaqus软件能够对土体的变形和流动进行耦合分析，在Abaqus中使用欧拉网格来划分土体单元，可以模拟土壤在外力作用下的流动变形。

2.1 桩-土系统模型

 图 2 桩靴滑移数值模型 Fig. 2 Model used in simulation of anti-slide
2.2 桩-土模型材料参数选择

2.3 边界条件及接触

2.4 载荷施加

3 桩靴抗滑移结果分析与讨论 3.1 抗滑移阻力理论计算

 ${R_c} = 1.88\;{\rm{MN}},{R_{cf}} = 0.29\;{\rm{MN}},{R_H} = 2.17\;{\rm{MN}}{\text{。}}$

3.2 数值解结果分析

 图 3 桩靴所受阻力曲线 Fig. 3 Resistance curve of spudcan
3.3 理论与数值解对比分析

3.4 滑移过程中土壤的流动分析

 图 4 土壤流动过程 Fig. 4 Flow process of soil
4 结　语

1）国内外学者对桩靴滑移理论的研究存在不足，传统理论公式中抗滑移阻力来自于土壤的粘附力和摩擦力，该方法只是在静态工况下以某一时刻的土壤材料属性来计算其抗滑移阻力，而桩靴在工作状态下会发生微小位移，同时土壤还会发生流动，容易产生误差。

2）数值解是以实际状况下模拟桩靴在微小滑移过程中，所得结果选取的是微小滑移过程中受到的最大阻力值，能够较为精确地得出抗滑移阻力。综合2种结果，2种不同方法得出的阻力都能够保证平台抗滑移稳性。与理论值相比，数值解能够更好的在动态下反映土壤的抗滑移属性，并且得到土壤的流动情况。

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