隔离桩对堆载下群桩下拉荷载的屏蔽效应  

Shielding Effect of Isolation Piles on the Dragload of Pile Group under Surcharge load

作　　者：原华[1,2,3] 李云星 任冠洲 李临庆 YUAN Hua;LI Yun-xing;REN Guan-zhou;LI Lin-qing(School of Civil Engineering and Architecture,Henan University,Kaifeng 475004,China;Institute of Geotechnical and Rail Transport Engineering,Henan University,Kaifeng 475004,China;Henan Rail Transit Intelligent Building Engineering Technology Center,Kaifeng 475004,China;Luohe Institute of Municipal Engineering Design,Luohe 462000,China)

机构地区：[1]河南大学土木建筑学院,开封475004 [2]河南大学岩土与轨道交通工程研究所,开封475004 [3]河南省轨道交通智能建筑工程技术中心,开封475004 [4]漯河市市政工程设计院,漯河462000

出　　处：《科学技术与工程》2020年第34期14201-14206,共6页Science Technology and Engineering

基　　金：国家自然科学基金(51508163);河南省重点研发与推广专项(科技攻关)项目(202102310247)。

摘　　要：目前关于隔离桩对堆载下群桩负摩阻力及下拉荷载屏蔽效应的研究较少,中国规范也未对隔离桩的设计参数给出建议。定义下拉荷载屏蔽效应系数这一概念;建立考虑桩-土作用的三维有限元模型,通过数值计算结果与模型试验数据的对比,验证数值模型的准确性。以群桩效应系数和下拉荷载屏蔽效应系数为评价指标,研究隔离桩对堆载下基桩负摩阻力与下拉荷载的屏蔽效果,分析隔离桩桩长、边长、与最外侧基桩间距3个因素对屏蔽效果的影响规律,对隔离桩的设置给出参考。研究成果可为堆载时群桩负摩阻力的消除及隔离桩的优化设计提供参考。At present,research on the shielding effect of isolation piles on the negative skin friction(NSF)and dragload of pile group under surcharge load with the isolation piles are scarce.The concerning national technical code does not give advice for the design parameters of isolation piles.Therefore,concept of shielding effect coefficient on dragload was defined,and then a three-dimensional finite element numerical analysis considering pile-soil interaction was established.The accuracy of the numerical model was verified by being compared with that of the model test data.Taking the pile group effect coefficient and the shielding effect coefficient for dragload as the evaluation indexes,the shielding effect of isolation piles on the NSF and dragload of pile group under surcharge load was studied.The influence of three parameters(isolation pile length,the isolation pile side length,and the distance between the outermost foundation pile and isolation pile)was investigated,and suggestions were given for the setting of isolation piles.This results can provide references for the elimination of the NSF of pile group and the optimization design of the isolation pile under surcharge load.

关 键 词：群桩 堆载 隔离桩 负摩阻力 下拉荷载 屏蔽效应 

分 类 号：TU473[建筑科学—结构工程]