明挖施工条件下的预制装配式隧道结构，其拼装技术与装配整体式结构或盾构隧道均存在较大差别，在工程设计阶段，需要根据结构型式和装配模式，对拼装进行详细的规划和设计，以支撑高质量、高效率施工，并确保结构承载性能和稳定性，同时满足接头接缝防水性能要求。本文结合作者及其团队多年来在明挖装配式地铁车站建造技术方面的研究和实践成果，对拼装设计方法及关键技术进行了系统性总结和论述，提出了拼装方法、基面精平技术、定位控制技术、张拉锁紧技术、支顶限位措施、精度控制标准等拼装关键技术。明挖装配式隧道结构拼装应以首环固定端为起点，沿纵向推进，遵循“先下后上”，逐块、逐层向上的拼装基本原则；基坑底部基面应进行精平处理，并根据地基条件和底板结构型式，可选择采用精平条带法或基面统平法；隧道衬砌结构宜在接头拼接面设置一定数量的导向定位装置，在辅助构件精确定位的同时，有效控制结构表面错台量；明挖装配式隧道宜尽量设置在直线上，当隧道位于曲线地段时，可采用 “楔形构件+等宽缝”或“等宽构件+楔形缝”的方式拟合曲线，但楔形缝的最大缝宽应满足接缝防水性能要求，且拼装精度控制难度大，施工具有一定的挑战性；纵向和环向拼装张拉锁紧，宜采用预应力钢棒张拉锁紧或螺栓锁紧方式，预应力张拉宜采用“形心跟踪法”，并应多点协同、同步张拉锁紧，保持接缝宽度的均匀性，有效控制目标接缝张开量，并对预制底板下空隙及时注浆填充，在侧墙和拱脚等关键部位及时支顶限位。

The assembly technology of prefabricated tunnel structure under open-excavated construction is quite different from shield tunnel. In the engineering design stage, the structural assembly needs to be planned and designed in detail according to the structural type and assembly mode, so as to support high-quality and efficient construction, ensure the bearing performance and stability of the structure, and meet the waterproof performance requirements of joints. Based on the research and practical achievements of the author and his team in the construction technology of open-excavated prefabricated metro stations over the years, this paper systematically summarizes and discusses the assembly design method and key technologies, and puts forward the assembly method, base surface fine leveling technology, positioning control technology, tension locking technology, roof support limit measures, precision control standards and other assembly key technologies. In general, the open-excavated prefabricated tunnel structure shall take the fixed end of the first ring as the starting point, proceed along the longitudinal direction, and follow the basic principle of "from bottom to top", and assembly block by block and layer by layer. The base surface at the bottom of the foundation pit shall be finely leveled, and according to the foundation conditions and the structural type of the bottom plate, fine leveling strip method or foundation surface leveling method can be selected. The tunnel lining structure should be equipped with a certain number of guiding and positioning devices at the joint assembling surface to effectively control the dislocation of the structure surface while helping to accurately locate the components. The open-excavated prefabricated tunnel should be set on a straight line as far as possible. When the tunnel is located in a curved section, the curve can be fitted by means of "wedge-shaped component + equal width joint" or "equal width component + wedge-shaped joint". However, the maximum joint width of the wedge-shaped joint should meet the requirements of joint waterproof performance, and it is difficult to control the assembly accuracy, so the construction is challenging. The tensioning and locking of longitudinal and circumferential assembly should adopt the tensioning and locking method of prestressed steel bar or bolt. The "centroid tracking method" should be used for prestressed tensioning, and the multi-point coordination and synchronous tensioning and locking should be used to maintain the uniformity of the joint width, effectively control the opening of the target joint width, and timely fill the gap under the prefabricated bottom plate with grouting, and timely support and limit the side wall, arch foot and other key parts.

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国家重点研发计划(2017YFB1201104)，北京城建集团创新项目(新型预制装配式地下车站结构模型试验研究)