【作者】 刘丰军；

【导师】 朱合华； 廖少明；

【作者基本信息】 同济大学 ， 结构工程， 2007， 博士

【摘要】 盾构法隧道已被广泛应用于城市地下铁路、越江通道和地下管线等隧道工程中。由于混凝土自身的特点，盾构法隧道常用的预制钢筋混凝土管片存在着自重大、裂缝不易控制、不宜承受拉力等缺点；同时，管片间的螺栓联接费用高、工序复杂，而且对管片接头部位的制作要求高。预应力混凝土技术既可以克服普通混凝土结构的缺陷，又可以作为一种装配手段，在工程结构中得到大量的应用。为了把预应力技术应用到盾构隧道衬砌结构，有必要对盾构法隧道预应力衬砌的设计理论和设计方法进行研究，从而科学地指导预应力管片的设计与施工，推动预应力管片的应用。在总结相关文献和研究的基础上，对预应力衬砌纵向接缝的力学性能进行研究。首先推导出接缝的张角计算公式，并将理论计算结果与模型试验结果和数值模拟结果进行对比，表明了该公式的可靠性；其次利用理论公式探讨不同预应力筋位置、不同偏心距对接缝性能的影响；随后基于构件内力比预应力度的概念提出预应力轴力比，并分析不同预应力轴力比下的接头性能。基于荷载一结构法，对预应力衬砌的结构模型和计算方法进行了研究。预应力衬砌结构中预应力的作用表现在两个方面：对接缝的作用和对衬砌结构的作用，预应力对衬砌结构的作用采用等效荷载考虑。提出了预应力衬砌的连续非均匀刚度模型，该模型既可以反映预应力管片接头刚度对结构受力的影响，又可以反映接头部位由于刚度偏小而出现结构弯矩的重分布现象。结合算例给出预应力衬砌理论计算的过程并与数值模拟结果进行比较；随后利用连续非均匀刚度模型分析了不同预应力轴力比对衬砌结构的影响。基于概率极限状态设计方法和预应力度的概念，研究了预应力衬砌的设计方法，给出了预应力衬砌的设计计算的具体步骤并对其构造设计进行探讨。以地铁隧道及有内压的输水隧道为例，进行了预应力衬砌工程应用和技术经济分析。更多还原

【Abstract】 Shield tunnel has been widely used in the construction of subway, underwatertunnels and underground pipeline projects, etc. Because of the connaturalcharacteristics of the concrete, the normal reinforced concrete segments have manydisadvantages, such as heavy weight, difficulty of crack control and lower ofbearing tensile force, etc. To the bolt connection of segments, the cost is expensive,and the construction procedure is complex. Overcoming the disadvantages ofcommon concrete as well as being used as an assembling method, the prestressedconcrete is widely used in engineering structures. In order to introduce theprestressing method into the structure of shield tunnel lining, it is necessary to studythe desigri philosophy of prestressed concrete linings. The study can not only guidethe design and constructions of shield tunnel prestressed segments scientifically, butalso promote the applications of prestressed segment.Based on the literatures and the existent researches, the study on segments jointof prestressed lining has been carried out. Firstly, the theoretical equations forcalculating the opening angle of the joint are deduced. Compared With the results ofexperiments and numerical simulations, the calculated value suggests that thetheoretical equations are reliable. Secondly, the influences of different prestressingcable positions and varying eccentricities on the joint characteristics have beendiscussed. Finally, the ratio of prestressing to axial force is defined. And itsinfluence to the joint characteristics has been also discussed.With the load-structure method, the structure model of prestressed lining hasbeen studied. The effects of prestressing on the tunnel lining include the effects onthe segment joint and the effects on the lining ring. The equivalent load ofprestressing can be used to represent the effects on the lining ring. Compared withthe beam-spring model and the modified-routine-method model, thecontinuous-nonuniform-rigidity model—a new structure model of tunnel lining hasbeen brought up in this thesis. The new model can not only represent the effects ofprestressing on the segment joint, but also show the moment redistribution aroused by the rigidity’s decrease of the joint. Combined with the case study, the calculationprocess for the prestressed lining structure is given. And the results of theoreticalcalculations and numerical simulations are compared. At the same time, the newmodel is used to analyze the effect of ratio of prestressing to axial force on thelining structure.According to the probability-based limit state design method and the concept ofprestressing degree, the design method of prestressed lining has been discussed. Thedesign process is given. The detail for calculation and constructional design are alsoanalyzed.Using the design philosophy of prestressed concrete linings discussed above, asubway tunnel lining and a water transport tunnel lining have been designed. Basedon these tunnel designs, the technical economy analysis of prestressed concretelinings has been mentioned.更多还原