【作者】 张弢；

【导师】 张明； 付云升；

【作者基本信息】 清华大学 ， 水利工程（专业学位）， 2015， 硕士

【摘要】 东干渠是北京市南水北调配套工程供水环路的重要组成部分,东干渠全长约44.7km,隧洞采用单孔圆形断面,内径4.6m、外径6m,全线采用盾构法施工。北京轨道交通机场线全长为28.1km,由二环东直门站向东北方向延伸,直至北京首都国际机场的T2、T3航站楼站。东干渠输水隧洞下方穿越地铁机场线三元桥站~T2航站楼站区间,穿越位置地铁为地面U型槽结构,输水隧洞埋深16.5m,输水隧洞距离机场线U型槽结构净距14.36m。东干渠输水隧洞穿越既有轨道交通结构和线路时,工程实施过程中将会对轨道交通产生不利的影响,会使既有轨道交通结构产生一定程度的变形,甚至造成列车的限速运营,极大地影响了地铁的服务质量。因此,穿越方案的选择、施工步序指标制定以及施工中变形预测等因素,对于新建隧洞穿越既有地铁结构和线路有重要意义。本文对南水北调东干渠输水隧洞穿越北京轨道交通机场线方案进行评估分析研究,对类似工程具有一定的参考价值。本文的主要研究内容如下:(1)针对本工程,计算选用ANSYS软件,建立三种盾构穿越方案的三维有限元数值模型,分别为未采用加固措施盾构穿越施工方案,采用注浆加固措施盾构穿越施工方案和采用桩基托换措施盾构穿越施工方案。数值模型计算模拟施工过程,从U型槽结构变形、既有地铁轨道结构变形等方面,对三种穿越方案进行对比,采用变形数值最小的注浆加固措施穿越方案作为最终方案。(2)根据最适合本工程的穿越方案,结合现行标准规范,利用相应的数值分析方法,确定了本工程施工变形和沉降控制标准。隧洞穿越施工过程中开展变形监测,通过实时的变形监测及数据整理分析,监测数据和数值计算结果相近。(3)总结本工程的成功经验,为类似工程提供了实用的指导方法。在类似的穿越工程方案确定时,可以通过有限元计算手段对各个方案进行数值模拟,得出定性及定量的结论,用于对方案进行比选,同时结合工程实践确定穿越方案,保证穿越安全。更多还原

【Abstract】 East canal is an important part of South-to-North Water Diversion Auxiliary Project, the length of East canal is 44.7km, the tunnel use single circular section with inner diameter of 4.6m, outer diameter of 6m, and the tunnel is constructed with TBM methods. The Airport Express line of the Beijing Subway is 28.1km long, from DongZhiMen station in the 2nd ring to Beijing International airport T2 and T3 terminal on northeast of Beijing. Inevitably, the shield tunnels of the South-to-North Water Diversion Project need to under-cross the Beijing Airport Express Line section between Sanyuanqiao station and T2 terminal, the metro line structure is U-groove, and the depth of East canal tunnel is 16.5m, the net distanse between metro structure and canal tunnel is 14.36 m. The under-crossing work will bring adverse effects to metro line. The metro structures may deform to some extent, which without correct design and construction may influence the normal speed of subway trains and even greatly low down the metro service level. Thus, the choosing of crossing proposals, the controlling of construction sequences standards, the prediction of deformation under construction and other factors will greatly influence the under-crossing results and are of significance to the project construction.The thesis focuses on the schemes of design and construction in water conveyance tunnels of east canal of the South-to-North Water Diversion under-crossing Beijing metro airport line, through the safety analysis of the metro structures. The analysis method, analysis results and experience of this thesis may provide a valuable reference for other similar projects.The main contents of this thesis are as follows:(1)Build three different numerical models with ANSYS software based on three construction methods of this project, compare with three different construction methods(without grouting, with grouting, and with pile supporting), and calculate the structure deformation and land subsidence, eventually find the best solution which is the grouting method that shows minimum deformation for this project through comparison.(2)Based on the recommended solution of this project and the current standards,the deformation control standards are proposed through numerical analysis. And the deformation survey is carried out during the construction, and the real time measured data and subsidence results are similar to calculation conclusions.( 3) Some successful experiences are summarized for providing practical experience for similar projects. The numerical analysis using finite element method can be used to calculate the different proposals and construction methods, and make qualitative and quantitative conclusions, and do comparison of the proposals, ensure the safety of the under-crossing project.更多还原