隔離樁對盾構掘進引起鄰近高鐵樁基水平位移的影響分析

馮國輝 周遜泉 何慶亮 徐長節

摘要：在城市建設過程中，盾構隧道開挖對鄰近既有高鐵樁基產生較大威脅，在隧道和高鐵樁基之間打入隔離樁可以有效減小盾構掘進對高鐵樁基的影響。在研究樁土相互作用領域中，Winkler地基模型和Pasternak地基模型得到了廣泛的運用。基于這兩種地基模型，采用差分法，利用Maple數學運算軟件對某實際工程案例分析，將計算結果與已有工程監測數據進行對比驗證，并深入分析隔離樁各項參數對高鐵樁水平位移的影響。結果表明，當隔離樁彈性模量較小時，Pasternak地基模型計算結果比Winkler地基模型更加精準;隨著隔離樁樁徑的增大，高鐵樁基水平位移顯著減小;在隔離樁樁體參數不變的條件下，縮短隔離樁與隧道中心線的水平距離能減小高鐵樁基的水平位移。

關鍵詞：地基模型;盾構隧道;樁土相互作用;鄰近開挖;隔離樁;位移

中圖分類號：TU433;U213.1 文獻標志碼：A 文章編號：20966717（2020）04002808

收稿日期：20191218

基金項目：國家重點基礎研究發展計劃（973 計劃）（2015CB057801）;國家杰出青年基金（51725802）;國家自然科學基金（51878276）;浙江省自然科學基金委員會華東院聯合基金（LHZ19E080001）

作者簡介：馮國輝（1996 ），男，主要從事土與結構相互作用研究，Email： 21812133@zju.edu.cn。

徐長節（通信作者），男，教授，博士生導師，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

隨著社會經濟的發展和人民生活水平的提高，城市隧道工程的建設也越來越多，其中不乏盾構隧道近距離穿越既有建筑或橋梁樁基的情況。盾構掘進對周圍土體產生擾動，造成土體變形，并進一步對鄰近樁基的應力應變場產生較大影響。……