摘要
超浅埋小净距大断面顶管隧道群工程顶推施工的背土效应会加剧周边地层变形,而采用减阻泥浆可有效缓解顶推施工对地层的扰动影响。为了研究超浅埋、小净距大断面矩形顶管隧道群工程顶推施工过程中减阻泥浆对地层土体变形规律的影响,采用三维有限元数值模拟方法,对隧道顶推施工过程中地层变形规律进行了研究,并将模拟结果与现场实测数据进行对比,得到如下结论:群洞隧道由于先后施工的影响,背土效应补充前方地层产生地表隆起变形;背土效应和土层应力共同影响下,在隧道高度范围和上覆土层范围,单洞隧道深层水平位移分别呈现偏离隧道和指向隧道的规律;地层位移影响分区决定了群洞隧道深层土体水平位移变形规律,后续开挖的隧道使得先行开挖隧道外边线以外土体全部产生背离隧道方向的水平位移。研究成果可用于帮助大断面矩形顶管等类似工程的设计施工,具有一定的推广意义。
The effects of back soil could increase soil deformation during constructing of large section rectangular pipe jacking tunnel group with super shallow depth. The influence on formation disturbance would be reduced by using drag reducing slurry during pushing. In order to analyze weakening effects of slurry on the soil deformation during construction for large section rectangular pipe jacking tunnel group with small spacing,the deformation regularity during pushing was studied by 3 D FEM numerical simulation,and the measured data in situ was contrasted as well. The conclusions are as follows. Due to the influence of construction for latter tunnels,surface heave were happened resulting from complements by back soil effect. For two influences of back soil effect and soil stress,the deep horizontal displacements of single tunnel deviates from the tunnel in the range of tunnel height,and points to the tunnel in the range of overburden layer. The influence partition of ground displacement determines the deformation law of deep soil horizontal displacement for tunnel group,and the excavations of subsequent tunnels leaded to deep horizontal displacement deviating from the tunnel for soil outside the edge of the former tunnel. The achievements will be used to help the design and construction for similar projects in the future,and these have a great significance of generalization.
作者
杨朝帅
邹翀
潘岳
YANG Chaoshuai;ZOU Chong;PAN Yue(China Railway Tunnel Group Co.,Ltd.,Guangzhou,Guangdong 511458,China;Guangdong Provincial Key Laboratory of Intelligent Monitoring and Maintenance of Tunnel Structure,Guangzhou,Guangdong 511458,China)
出处
《水利与建筑工程学报》
2021年第5期111-117,共7页
Journal of Water Resources and Architectural Engineering
关键词
矩形顶管隧道
地表沉降
深层水平位移
减阻泥浆
rectangular pipe jacking tunnel
surface settlement
deep horizontal displacement
drag reducing slurry