隔离桩对盾构掘进引起邻近高铁桩基水平位移的影响分析

冯国辉 周逊泉 何庆亮 徐长节

摘要：在城市建设过程中，盾构隧道开挖对邻近既有高铁桩基产生较大威胁，在隧道和高铁桩基之间打入隔离桩可以有效减小盾构掘进对高铁桩基的影响。在研究桩土相互作用领域中，Winkler地基模型和Pasternak地基模型得到了广泛的运用。基于这两种地基模型，采用差分法，利用Maple数学运算软件对某实际工程案例分析，将计算结果与已有工程监测数据进行对比验证，并深入分析隔离桩各项参数对高铁桩水平位移的影响。结果表明，当隔离桩弹性模量较小时，Pasternak地基模型计算结果比Winkler地基模型更加精准;随着隔离桩桩径的增大，高铁桩基水平位移显著减小;在隔离桩桩体参数不变的条件下，缩短隔离桩与隧道中心线的水平距离能减小高铁桩基的水平位移。

关键词：地基模型;盾构隧道;桩土相互作用;邻近开挖;隔离桩;位移

中图分类号：TU433;U213.1 文献标志码：A 文章编号：20966717（2020）04002808

收稿日期：20191218

基金项目：国家重点基础研究发展计划（973 计划）（2015CB057801）;国家杰出青年基金（51725802）;国家自然科学基金（51878276）;浙江省自然科学基金委员会华东院联合基金（LHZ19E080001）

作者簡介：冯国辉（1996 ），男，主要从事土与结构相互作用研究，Email： 21812133@zju.edu.cn。

徐长节（通信作者），男，教授，博士生导师，Email： xucj@zju.edu.cn。

Received：20191218

Foundation items：Major State Basic Research Development Program of China （973 Program） （No. 2015CB057801）; The National Science Fund for Distinguished Young Scholars （No.51725802）; National Natural Science Foundation of China （No. 51878276）;Joint Fund of the Natural Science Foundation of Zhejiang Province and Huadong Engineering Corporation Limited（No.LHZ19E080001）

Author brief：Feng Guohui （1996 ）， main research interests： soil and structure interaction， Email： 21812133@zju.edu.cn.

Xu Changjie （corresponding author）， professor， doctorial supervisor， Email： xucj@zju.edu.cn.

Analysis on the influence of isolation pile on horizontal displacement of adjacent pile under highspeed railway caused by shield driving

Feng Guohui1， Zhou Xunquan2， He Qingliang3， Xu Changjie1，4

（1.Research Center of Coastal and Urban Geotechnical Engineering， Zhejiang University， Hangzhou 310058， P.R. China; 2.Zhejiang Hanghai Intercity Railway Co.， Ltd.， Jiaxing 314000， Zhejiang， P.R. China; 3. Hangzhou CBD Construction Development Co.， Ltd.， Hangzhou 310020， P.R. China; 4.Jiangxi Key Laboratory of Infrastructure Safety Control in Geotechnical Engineering; Engineering Research & Development Centre for Underground Technology of Jiangxi Province， East China Jiaotong University， Nanchang 330013， P.R. China）

Abstract： In the process of urban construction， shield tunnel excavation will pose a great threat to the adjacent existing pile under highspeed railway. Driving isolation pile between the tunnel and highspeed railway foundation pile can effectively reduce the influence of the shield driving to adjacent pile foundation. In the field of pilesoil interaction， Winkler foundation model and Pasternak foundation model have been widely used. Based on these two foundation models， this paper uses the finite difference method by Maple mathematical software to analyse a practical engineering case. The calculated results are in accordance with existing engineering monitoring data. Then the influences of isolation pile of various parameters on the horizontal displacement of the pile under highspeed railway are further analyzed. The results show that Pasternak foundation model is more accurate than Winkler foundation model when the elastic modulus of isolation pile is smaller. With the increase of isolated pile diameter， the horizontal displacement of pile foundation will decrease significantly. The horizontal displacement of highspeed railway pile foundation can be reduced by reducing the horizontal distance between the isolated pile and the tunnel center line on the condition that the parameters of isolated pile remain unchanged.

Keywords：foundation model; shield tunnel; pilesoil interaction; adjacent excavation; isolation pile; displacement

随着社会经济的发展和人民生活水平的提高，城市隧道工程的建设也越来越多，其中不乏盾构隧道近距离穿越既有建筑或桥梁桩基的情况。盾构掘进对周围土体产生扰动，造成土体变形，并进一步对邻近桩基的应力应变场产生较大影响。……