【作者】 谢锋；

【导师】 蒋树屏；

【作者基本信息】 重庆交通大学 ， 桥梁与隧道工程， 2019， 博士

【摘要】 随着“城市提升行动计划”的实施,城市建设用地日益紧张,但城市人口数量不断增加,加之国内大都市轿车普及趋势不可阻挡,道路交通拥堵状况越加严重,城市交通拥堵已成为当今社会急需解决的一个焦点。因此,应大力推进交通强国战略。在此背景下,城市轨道、道路等基础设施不断增加,地下立交隧道也随之而出现。目前,关于地下立交等近接隧道的研究较少,尤其是针对新旧洞室相互作用的研究成果报道极少。为此,本文以导师蒋树屏重庆市科技人才培养计划(领军人才)项目“城市地下道路地层敏感度及结构适应性研究”为依托,利用数值分析、模型试验及现场监测,对岩体上下交叉隧道基于不同的埋深、围岩级别、隧道间距、施工顺序的立交隧道结构响应和施工力学问题开展研究,取得以下主要创新性成果。(1)利用三维有限元法对立交隧道进行计算,分析了既有隧道衬砌的应力增量和变形规律,根据应力增量控制标准,确定了立交隧道的相互影响范围、控制断面和控制点;(2)根据空间散点拟合原理,得出既有隧道衬砌应力增量与隧道埋深、围岩级别、隧道净距的函数表达式,并计算出不同的埋深、围岩级别、施工顺序的强、弱影响间距;(3)利用极限平衡法推导出立交隧道敏感性分析解析解,对不同的埋深、围岩级别、隧道净距进行敏感度单因素分析,给出了敏感度变化规律,指出了围岩级别>隧道净距>隧道埋深的敏感度影响顺序;(4)通过物理模型试验,对既有隧道衬砌应力增量变化规律及影响因素分析,指出了既有隧道衬砌破坏模式,同时验证了数值计算结果的正确性;(5)利用数值计算,对新建隧道加固、中间地层加固、既有隧道加固分别进行了分析,指出了加固措施对立交隧道影响的改善度与优先对策;(6)针对“零”隧道间距,提出了相应的施工关键技术与适应性结构,可用于超近间距立交隧道设计与施工;(7)将影响间距、地层敏感区结构参数运用于依托工程,通过现场实测,既有隧道应力增量变化规律、影响度与拟合公式计算结果相符,验证了本文地层敏感区支护结构参数可用于实践。更多还原

【Abstract】 With the implementation of "Urban Promotion Action Plan",urban construction land is becoming increasingly tense,but the number of urban population is increasing,coupled with the irresistible trend of car popularity in domestic metropolitan areas,road traffic congestion is becoming more and more serious,and urban traffic congestion has become a focus that needs to be solved urgently in today’s society.At the same time,the "19th National Congress Report" pointed out that China must be built into a powerful country for transportation.Therefore,in the city,metro,rail and other traffic is constantly emerging,with the underground traffic up-crossing and down-crossing existing tunnels constantly appearing.At present,there are few studies on the interaction between interchange tunnels,and the existing studies mainly focus on specific projects,lacking systematic and universal research.According to the requirements of the Ministry of Communications and the preliminary assumption of the Chongqing Transportation Bureau on the "Outline for the Construction of the Demonstration Zone of Chongqing’s Transportation Powerful Country",by 2035,the demonstration zone of Chongqing’s Transportation Powerful Country will be built in an all-round way,and the transportation of Chongqing will basically realize modernization and reach the international advanced Therefore,based on the project of Chongqing Science and Technology Talents Training Plan(Leading Talents)"Research on Stratum Sensitivity and Structural Adaptability of Urban Underground Road",this paper systematically studies the construction mechanics of interchange tunnels with different buried depth,different surrounding rock grade,different tunnel spacing and different construction sequence by means of numerical analysis,model test and on-site monitoring research methods.For the influence relationship and degree of existing tunnels,more economical and effective reinforcement measures are put forward for the main environmental sensitive areas,and a set of structural adaptability system for the influence area of interchange tunnels is formed.The main research contents of this paper are as follows:(1)to consult the existing data,summarize the research results of the near-connection construction of existing interchange tunnels,judge and classify the simulated interchange conditions,and comb out the calculation and test work.(2)On the basis of summarizing the past experience and achievements in engineering investigation,according to the characteristics of urban underground roads,the calculation models of overpass tunnel proximity with different burial depth,different surrounding rock grade,different proximity distance and different construction sequence are established,and the numerical calculation is carried out according to the combination of working conditions.(3)Based on the calculation results,the factors affecting the intersection of underground overpass tunnels are studied,and the function expressions of stress and tunnel burial depth,surrounding rock level,and proximity distance are derived using the principle of spatial dispersion fitting and tunnel construction mechanics.The influence spacing of different buried depth,different surrounding rock level and different construction sequence was studied.(4)The sensitivity zoning and zoning index of underground engineering adjacent to different interchange tunnels are studied.The analytical solution of sensitivity analysis of interchange tunnels is deduced by limit equilibrium method.The sensitivity of different buried depth,different surrounding rock grade and different tunnel net distance is studied by single factor method,and the corresponding sensitivity index is put forward.(5)Through indoor model test,the stress distribution and influence of new tunnel construction on existing tunnel lining under different tunnel clearance are studied,the failure modes of existing tunnel are analyzed,and the numerical results are verified;(6)According to the existing projects and the above research results,according to the control indicators,the monitoring and measurement plan of the interchange tunnel is studied,and the impact of the construction of a new tunnel on the existing tunnel is monitored and analyzed on the spot.The rationality of the control indicators and the correctness of the analytical formula are verified.(7)According to the sensitivity zoning method of interchange tunnels developed in this paper,the adaptability analysis of commonly used structures is carried out,and the structural adaptability Countermeasures of different sensitive areas are put forward.At the same time,the special construction methods and adaptable structures of strong sensitive areas are put forward,which provide technical basis for the design and construction of Interchange tunnels and improve and promote the development of interchange tunnel construction technology.更多还原