摘要
为研究基坑开挖对临近既有地铁隧道结构的影响,以济南历下医养结合中心项目近接地铁R3线施工为工程背景,开展风险判定并采用FLAC3D进行大型三维数值模拟研究。结果显示:基坑外部作业对地铁隧道的影响等级为二级;隧道开挖引起地表沉降模拟结果与实测数据基本吻合,数值模拟结果较可靠;基坑开挖引起左线隧道竖向位移最大-2.27 mm、水平位移最大4.59 mm,右线隧道竖向位移最大-3.0 mm、水平位移最大5.19 mm,左线隧道轨道竖向位移最大-2.27 mm、轨向高差最大0.528 mm,右线隧道轨道竖向位移最大-3.0 mm、轨向高差最大0.763 mm,均出现在B基坑西侧;基坑开挖引起径向附加压力很小,在10~20 kPa范围内。总体上基坑开挖对隧道结构造成的影响均小于规范限值。
To study the influence of foundation pit excavation on the structure of nearby subway tunnels,the construction of the Medical Center Project near the R3 subway line in Lixia District,Jinan City was taken as the engineering background,the risk evaluation was carried out and FLAC3D was used for large-scale three-dimensional numerical simulation.Results show that the impact degree of the external work of the foundation pit on the subway tunnel is the’Secondary’.The simulation results of the ground surface settlement caused by tunnel excavation are consistent in overall with the field measured data,which means the numerical simulation results were reliable.The largest vertical displacement of the left-line tunnel caused by the foundation pit excavation was-2.27 mm,and the maximum horizontal displacement was 4.59 mm.The others were:the vertical displacement of the right-line tunnel:-3.0 mm,and the horizontal displacement:5.19 mm;the vertical displacement of the left-line rail:-2.27 mm,and the height difference of the rails:0.528 mm;and the vertical displacement of right-line rail:-3.0 mm,and the height difference of the rails:0.763 mm.The largest displacement caused by the foundation pit excavation appeared in the west side of foundation pit B.The radial additional pressure caused by the excavation of the foundation pit was small from 10~20 kPa.In general,the impact of the foundation pit excavation on the subway tunnel structure did not exceed the limit of the relevant code,thus the operation shall be save.
作者
张兵兵
卢伟晓
李为腾
ZHANG Bing-bing;LU Wei-xiao;LI Wei-teng(Jinan Rail Transit Group Co.,Ltd.,Jinan 250101,China;Shandong Provincial Key Laboratory of Civil Engineering Disaster Prevention,Shandong University of Science and Technology,Qingdao 266590,China)
出处
《科学技术与工程》
北大核心
2020年第35期14673-14680,共8页
Science Technology and Engineering
基金
国家自然科学基金(51604166)
青岛市博士后应用研究项目(2016130)。
