【作者】 夏炜洋；

【导师】 何川；

【作者基本信息】 西南交通大学 ， 桥梁与隧道工程， 2012， 博士

【摘要】 盾构法修建隧道一般都与地下水密切相关,其位置大都处于江河湖海水底复杂的工程地质和水文地质环境当中,盾构隧道穿越的地层既有砂质等软弱地层,也有较硬的裂隙岩体,不论何种地层,都将遇到盾构隧道施工过程中的流固耦合问题。在盾构隧道工程中,荷载的取值是设计和施工中关键参数,围岩和地下水两者耦合问题,会带来荷载的分布特征发生很大改变,因此,在含地下水的盾构隧道研究中,施工期的流固耦合问题是一个复杂而重要的课题。论文依托国家自然科学基金项目“大型跨江海盾构法隧道施工期流固耦合问题研究”,以重庆主城排水盾构隧道和成都地铁1号线盾构区间隧道为工程背景,采用理论分析、数值模拟计算、现场测试、室内模拟试验等多种分析方法,围绕盾构隧道施工中的流固耦合问题和泥水盾构机的模拟试验问题,对不同地层条件下的盾构隧道衬砌结构的施工期内力和可靠性进行了系统的研究。为弥补理论分析方法和数值计算不能处理及不可表征的因素对隧道结构物的影响问题,研制了泥水平衡式模型盾构试验系统,作为其他研究手段的补充。主要研究成果如下：1、针对盾构隧道施工过程中的流固耦合问题,从岩体力学、渗流力学和弹塑性理论出发,具体推导了盾构隧道围岩和结构的渗流场和应力场计算公式。分析了围岩塑性理论的不同屈服准则,选择适用于工程的Drucker-Prager准则作为解析法计算的基础,进行围岩和衬砌结构的内力分析。根据土体和岩体不同的力学特性,给出了其相应的渗透系数和应力之间的关系式,以此为中间桥梁,得出了按流固耦合理论计算的盾构隧道管片衬砌内力的解析解。2、以渗流场-应力场耦合机理为基础,采用大型有限元软件,针对围岩以岩质为主的地层结构,结合高水压条件下盾构隧道的实际工程——重庆主城排水过长江盾构隧道工程,对施工期盾构隧道围岩及主体结构的渗流场和应力场进行了二维流固耦合分析,研究了高水压作用下盾构隧道围岩及主体结构的流固耦合问题,分别针对不同水压情况下和隧道掘进过程中的工况进行了分析,探明了地下水压对于施工期的管片结构的影响,并与现场试验结果进行相互验证；针对含围岩以含地下水丰富的砂卵石地层为主的成都地铁1号线盾构区间隧道,进行了施工期流固耦合的二维和三维计算,研究了流固耦合条件下结构主体的内力分布和盾构掘进对周边结构的影响。3、提出了将有限元程序与区间解法相结合以求解隧道衬砌内力的方法,分析了单个随机变量对隧道衬砌内力的影响水平,将各随机变量进行参数的最不利组合,调用有限元程序来求解衬砌的内力区间值。4、为了解决泥水盾构机水下掘进控制和泥水平衡机理,研制了可模拟真实地下水加压的物理模拟装置,在此基础上完成了流固耦合条件下功能验证为主的泥水盾构全过程掘进模拟试验,分析了掘进过程中盾构对地表的位移影响,得出了一些规律性的试验结论；进行了泥膜对地层渗透性影响的基本试验,在此基础上,根据成都砂卵石地层参数特点配置了相似土体,采用试验方法确定了泥浆材料,并完成了泥膜形成的模拟试验；模拟了粉质黏土的地层配置,并进行了泥膜的成型试验,通过上述试验,明确了不同地层中泥膜的形态。随着我国交通事业的迅速发展,盾构隧道的日益增长,上述关于盾构隧道流固耦合问题的研究,对于保障盾构隧道施工期的安全,具有重要的意义。而泥水平衡模型试验系统的建成,可在盾构隧道建设过程中,针对性地为各类条件的地层提供盾构掘进模拟试验,从而为盾构隧道的施工和盾构机的设计提供重要参考价值。更多还原

【Abstract】 Construction of shield tunnel generally is closely related to ground water. Its location is usually located in the rivers, lakes, sea bottom where exist the complex engineering geology and hydrogeology environment. Through the strata both soft ground and hard fractured rock, shield tunnel will inevitably encounter the problem of coupled solid-fluid during tunnel construction period. For shield tunnel engineering, the load value is the design and construction of key parameter, the coupling effect on surrounding rock and groundwater will bring the distribution of load changed significantly. Therefore, the problem of coupled solid-fluid during construction period is a complex and important issue in the research on shied tunnel with ground water.According to the National Natural Science Foundation of China project’study on solid-fluid coupling of large-scale shield tunnel during construction period’, cooperating the drain tunnel project crossing Yangtze River in the downtown of Chongqing city and shield section tunnel in Chendu metro line1as the engineering background, by means of theoretical analysis, numerical simulation, in-situ testing, laboratory tests and other methods considering the problems of coupled solid-fluid caused by shield tunnel construction and slurry shield machine simulation test, the internal forces of segments lining and reliability are studied systematically during construction period of the different soil layers. In order to make up the limitation about theoretical analysis and numerical calculation, a set of slurry shield simulation test system is developed, as a supplementary means of other studies. The main results are as follows:1. For the problem about coupled solid-fluid during construction period, using rock mechanics, seepage mechanics and elastic-plastic theory, the calculation formulas of seepage field and stress field for surrounding rock and structure is deduced. Through analyzing different plasticity yield criterion, Drucker-Prager criterion is selected as the basis of analytic method for calculating the internal force of surrounding rock and the lining. In light of the different soil and rock mechanical properties, the formula of the permeability coefficient and the corresponding stress furthermore, analytical solution of shield tunnel lining internal forces is obtained by coupled solid-fluid theory.2. Based on coupling mechanism between seepage field and stress field, using finite element software, for the surrounding rock that consists mainly of rock strata, combined with high pressure water shield tunnel of the drain tunnel project crossing Yangtze River in the downtown of Chongqing city, this paper carried out the construction of tunnel surrounding rock and the main structure of the seepage field and stress field analysis of two-dimensional coupled solid-fluid. The effects on surrounding rock and the main structure of coupled solid-fluid problems under high water pressure and under different pressure conditions during tunneling period were studied respectively, the research gives the water pressure having effect on the segment of lining structure, and the result is testified by field test data. For the ground consisting of mainly sand and gravel with rich groundwater of the shield interval tunnel in Chengdu metro line1, the two-dimensional and three-dimensional coupled solid-fluid calculation are carried out, the internal force distribution of lining structure and the impact on the surrounding structure caused by excavation the tunneling are studied.3. This paper put forward a method which combining FEM and interval solution method for getting the tunnel lining internal forces. A single random variable internal force of the impact of the level of the tunnel lining is analyzed. Parameters of random variables are treated by the most unfavoured combination. Finite element program is called to solve the interval values of lining internal force.4. In order to solve the tunneling control of slurry shield machine and mechanism of slurry balanced, a physics simulation device is developed that it can realize the simulation of the real groundwater pressure. On the basis of complete functional verification-based simulation of slurry shield tunneling process of testing, analysis of the shield tunneling having effects on the surface, as a result, the paper draws conclusions regular rules of slurry shield testing.Through the membrane formation mechanism of mud, the test that filter-cake for a fundamental impact on the formation permeability is carried out. Based on above, the simulation soil is manufactured cooperating the sand and gravel parameters in Chengdu characteristics. The slurry material is determined by test methods, and the formation of filter-cake simulation test film is completed. The states corresponding different strata is revealed.With the rapid development of transport, the growing shield tunnel, the results about coupled solid-fluid has important significance for the protection of shield tunnel construction safety. The slurry shield micro simulation test system is not only to study the problems of slurry shield construction for all types of conditions, but also to provide an important reference value for the construction of shield tunnel and design of machines.更多还原