双孔隧道中后掘进盾构对地表沉降的影响  

Influence of Subsequent Shield Tunneling on Ground Surface Settlement during Construction of Twin Tunnel

作　　者：罗雄文 张文广 梁荣柱[2,3,4] LUO Xiong-wen;ZHANG Wen-guang;LIANG Rong-zhu(School of Civil and Environmental Engineering,Hunan University of Science and Engineering,Yongzhou Hunan 425199,China;School of Engineering,China University of Geosciences(Wuhan),Wuhan Hubei 430074 China;School of Civil Engineering and Architecture,Zhejiang University,Hangzhou Zhejiang 310058,China;School of Civil Engineering and Architecture,Guangxi University,Nanning Guangxi 530004,China)

机构地区：[1]湖南科技学院土木与环境工程学院,湖南永州425199 [2]中国地质大学(武汉)工程学院,湖北武汉430074 [3]浙江大学建筑工程学院,浙江杭州310058 [4]广西大学土木建筑工程学院,广西南宁530004

出　　处：《公路交通科技》2020年第9期82-89,共8页Journal of Highway and Transportation Research and Development

基　　金：国家自然科学基金项目(41807262);中国博士后科学基金项目(2019M653308);湖北省自然科学基金项目(2018CFB179);湖南科技学院科研课题项目(19XKY057)。

摘　　要：受地下空间限制,城市地铁双线隧道间净距较小,后掘进盾构隧道施工将引发地层二次扰动,导致额外地层变形,对临近构筑物安全威胁尤甚。当前研究主要基于地表横向沉降曲线研究双线隧道掘进引起地表的沉降规律和地层扰动特点,但地表横向沉降曲线不能全面反映前、后掘进盾构隧道施工引起的地表沉降发展过程及规律。以杭州地铁某区间双线盾构隧道地表沉降长期监测数据为依托,采用地表沉降时程曲线和地表横向沉降曲线相结合的方法,分析双线盾构隧道前、后掘进引起的地表沉降规律。研究表明,后掘进隧道引起的土体损失率在0.6%~0.8%之间,地表最大沉降量在15.2~20.7 mm之间,均大于先行隧道引起的土体损失率和地表最大沉降量;由于后掘进盾构对地层的二次扰动,导致最终地表沉降槽曲线并不严格关于双线隧道轴线中点对称分布,地表沉降最大值略微偏向后掘进隧道轴线。通过地表沉降时程曲线发现,先行盾构通过监测断面后,地表沉降迅速发展,主要沉降范围在隧道轴线6 m范围内;由于先行盾构隧道掘进扰动,在后掘进盾构到达前2天(约3倍盾构直径距离)地表开始发生明显的沉降;在后掘进盾构施工影响下,所引起其轴线处地表沉降量大于先行掘进盾构所对应的轴线处沉降值。Due to the limit urban underground space,the clearance of the urban metro twin tunnel is small.The subsequent shield tunneling will cause ground secondary disturbance and lead to additional ground deformation,which may threat the safety of adjacent underground structures.The current researches are mainly based on the ground surface transverse settlement curve to study the ground subsidence rule and stratum disturbance characteristics caused by twin tunnel excavation.However,the ground surface transverse settlement curve cannot fully reflect the development process and rules of surface subsidence caused by the first and the subsequent shield tunneling.Based on the long-term measured ground surface settlement data of a twin tunnel section of the Hangzhou Metro,the rules of ground surface settlement induced by the first and the subsequent shield tunneling are analysed by ground surface settlement time history curves and ground surface transverse settlement curves.The result shows that(1)the subsequent shield tunneling induced ground volume loss ratio varies from 0.6%to 0.8%,and the maximum surface settlement is between 15.2 mm and 20.7 mm,which are greater than the ground volume loss ratio and the maximum surface settlement caused by the first shield tunneling;(2)due to the secondary disturbance by the subsequent shield tunneling,the final ground surface settlement trough curve is not strictly symmetrical about the midpoint of the twin tunnel axis,and the maximum surface settlement is slightly offset to the subsequent tunneling axis.The ground surface settlement time history curves show that(1)after the first shield tunneling passing through the monitoring section,the surface settlement developed rapidly,and the main settlement range is within 6 m of the tunnel axis;(2)due to the disturbance of the first shield tunneling,the ground surface settlement begun to develop obviously 2 days before the arrival of the subsequent shield tunneling(about 3 times of the shield tunneling diameter);(3)because of the influence of t

关 键 词：隧道工程 地表沉降 现场实测 盾构掘进 双孔隧道 

分 类 号：U455.43[建筑科学—桥梁与隧道工程]