摘要
工程实践表明,浅覆软弱地层中大直径小净距盾构隧道施工时,后行隧道施工显著影响先行隧道的安全.依托某盾构隧道工程,采用精细化数值模拟技术,建立盾构隧道施工模型,分析小净距浅埋盾构施工相互影响,并对不同净距下盾构隧道施工相互影响规律进行分析.结果表明:双线浅埋盾构隧道施工时,净距与地表沉降槽宽度呈线性正相关,与沉降峰值、管片附加变形、接头张开量和附加拉应力呈负相关;浅覆软弱地层盾构施工时应避免将封顶块置顶;陈村2号隧道净距小于5m区段,先行隧道管片内力不满足规范要求,采取“隔断墙+水泥土搅拌桩”控制措施,实测和数值结果均表明控制效果良好,研究成果可为后续类似工程设计和施工提供参考.
According to engineering practice,the construction of the second shield tunnel in shallow soft stratum reduces the safety of the first shield tunnel,especially when the clear distance of the two tunnels with large diameter is very small.Based on a shield tunnel project,refined numerical models are built to simulate the shield construction.According to the numerical results,the interaction mechanism of shield construction and the interaction law under different clear distance of the double-line parallel shield tunnel are analyzed.The results show that there is a positive linear correlation between the clear distance and the width of the surface settlement trough,and a negative correlation between the clear distance and the peak value of settlement,additionaldeformation of segment,joint opening and additional tensile stress.The top block should not be placed on top of the segment in the shield construction on shallow-buried soft stratum.In the No.2 tunnel sector of Chencun where the clear distance is below 5 m,the segment internal force of the first shield tunnel fail to meet the standard requirement,the"partition wall accompanied by cement-soil mixing pile"is applied as an effective control measure,which is also verified valid by comparing with the field test.This study lays basis for the design and construction of subsequent tunnelling projects subject to shallow buried depth and small clear-distance.
作者
赵乙丁
刘守花
阳军生
傅金阳
杨安民
刘玮
ZHAO Yiding;LIU Shouhua;YANG Junsheng;FU Jinyang;YANG Anmin;LIU Wei(School of Civil Engineering,Central South University,Changsha 410075,China;Wuhan Municipal Engineering Design&Research Institute Co.,Ltd.,Ltd.,Wuhan 430000,China;Guangdong Huasui Construction Co.,Ltd.,Guangzhou 510620,China)
出处
《北京交通大学学报》
CAS
CSCD
北大核心
2020年第1期120-128,共9页
JOURNAL OF BEIJING JIAOTONG UNIVERSITY
基金
国家自然科学基金(51608539)。
关键词
软弱地层
盾构隧道
相互影响
精细化数值模拟
控制措施
soft stratum
shield tunnels
interaction
refined numerical simulation
control measures
