考虑桩基弱化效应的桩-土相互作用研究  

Research on pile-soil interaction considering degradation of pile foundation

作　　者：钟超 毛东风[2] 倪明晨 黄佳 闫琛 李晓慧 张涛[3] 

机构地区：[1]北京高泰深海技术有限公司,北京100011 [2]中国石油大学(北京),北京102249 [3]西南化工研究设计院有限公司,四川成都610225

出　　处：《中国海上油气》2015年第6期98-104,110,共8页China Offshore Oil and Gas

基　　金：国家高技术研究发展计划(863计划)"基于振动检测的现役海洋平台结构安全评估技术研究"子课题"海洋平台桩基弱化及其对平台的影响研究(编号:2008AA092701-3)"部分研究成果

摘　　要：将桩-土相互作用模型的土体刚度与p-y曲线相结合,用p-y曲线的切线刚度作为土体刚度,修正了原有的桩-土相互作用模型,进行了循环荷载作用下桩基弱化规律的实验研究。通过实验数据分析,提出了横向循环荷载作用下极限土抗力的折减系数;将该折减系数代入p-y曲线计算公式,得到了考虑桩基弱化的p-y曲线;将桩-土相互作用模型的土体总刚度替换为修正后的p-y曲线的切线刚度,修正了土刚度的计算公式,使得修正后的模型可考虑桩基弱化效应的桩-土相互作用模型。进行了本文修正模型的有限元数值模拟和对照实验,结果显示土抗力和桩身位移的数值模拟结果与实验结果吻合较好,验证了该模型的准确性。本文提出的考虑桩基弱化效应的桩-土相互作用模型可以更加精确地模拟桩基作用,能够使在役导管架平台安全评估更加准确。A modified pile-soil interaction model was presented by substituting tangent stiffness of p-y curve for soil stiffness in the existing pile-soil interaction model. And several experiments on pile foundation deg- radation under cyclic loading were conducted. Based on the analysis of the experiment results, a pile foun- dation degradation coefficient was proposed, which can represent soil lateral resisting capability degradation. Substituting this coefficient to the p-y curve formula, a new p-y curve formula was obtained which takes degradation of pile foundation into account. The modified model was verified by numerical simulation and experiments. The soil resisting capacity and pile displacements from numerical simulation and experi- ment results are consistent. This model can be used to predict pile-soil interaction more accurately, which makes jacket platform safety assessment more reliable.

关 键 词：桩-土相互作用 桩基弱化实验 P-Y曲线 数值模拟 

分 类 号：TE243[石油与天然气工程—油气井工程]