- 摘 要
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(1 北京市基礎設施投資有限公司， 北京 100101； 2 北京城投地下空間開發(fā)建設有限公司，北京 100084； 3 清華大學水沙科學與水利水電工程國家重點實驗室， 北京 100084)
［摘要］以北京上下同步逆作法基坑工程為背景，運用PLAXIS 3D有限元軟件對上下同步逆作法基坑施工的全過程進行模擬，研究上下同步逆作法基坑的受力、變形特性及其對鄰近地鐵車站的影響。結果表明：上部結構施加的豎向荷載和地下連續(xù)墻水平荷載耦合會增大地下連續(xù)墻水平位移和彎矩；地下連續(xù)墻后有地鐵車站存在時，由于其遮蔽作用，地表沉降范圍隨開挖深度增加基本不變，最大沉降比無地鐵車站時大17%；隨開挖深度增加，二期立柱的隆起隨坑底隆起增大不斷增大，而一期立柱則在坑底隆起和上部荷載共同作用下由隆起逐漸轉為沉降；地鐵結構埋深和距基坑邊緣的距離對結構變形量和變形形式影響顯著，地鐵結構的最大變形與基坑開挖深度近似呈線性正相關。
［關鍵詞］上下同步逆作法；基坑；地鐵車站；數(shù)值分析；變形
中圖分類號：TU753 文獻標識碼：A文章編號：1002-848X(2021)15-0124-07
Analysis on deformation of deep foundation pit with synchronous top-down construction method and adjacent subway station
WANG Yao1,2, LI Bing2, YANG Jiaxin2, WANG Xiaohua2, JIN Hongliu3
(1 Beijing Infrastructure Investment Co., Ltd., Beijing 100101， China； 2 Beijing Urban Underground Space Development and Investment Co., Ltd., Beijing 100084， China； 3 State Key Lab of Hydrosciences and Engineering, School of Civil Engineering, Tsinghua University, Beijing 100084， China)
Abstract: Based on foundation pit project with synchronous top-down construction method in Beijing, PLAXIS 3D finite element software was used to simulate the whole construction process of the foundation pit project with synchronous top-down construction method, the force and deformation characteristics of the foundation pit with synchronous top-down construction method and the influence of its excavation on the adjacent subway stations were studied. The results show that the vertical load coupling with horizontal load on retaining wall will increase the horizontal displacement and bending moment of the retaining wall. When there is a subway station behind the diaphragm wall, due to its sheltering effect, the surface settlement range remains basically unchanged with the increase of the excavation depth, and the maximum settlement is 17% larger than when there is no subway station. As the excavation depth increases, the uplift of the second-stage column increases with the uplift increase of the pit bottom, while the first-stage column gradually changes from uplift to settlement under the combined action of the pit bottom uplift and the upper load. The buried depth of the subway structure and the distance from the edge of the foundation pit have a significant impact on the amount of structural deformation and the form of deformation. The maximum deformation of the subway structure is approximately linear positively correlated with the excavation depth of the foundation pit.
Keywords:synchronous top-down construction method； foundation pit； subway station； numerical analysis； deformation
作者簡介：王耀，碩士，高級經濟師，Email:wangyao@bii.com.cn； 通信作者：金紅柳，博士研究生，Email:1334281248@qq.com。
