明挖预制装配式隧道结构拼装精度控制标准研究与制定

明挖装配式隧道结构建造技术的研究和应用在我国尚属起步阶段，拼装精度控制标准是装配式结构建造过程中衡量和控制工程质量的重要尺度，标准的合理制定，关系到工程建设的安全可靠性、经济合理性及实际可操作性。通过拼装精度影响因素分析，提出了理论指标，并结合工程实际应用情况和实测值正态分布曲线的分析和提炼，给出了明挖装配式隧道结构拼装精度主要控制要素的控制标准，包括轴线平面定位偏差、高程定位偏差、构件形位姿态偏差、接缝张开量、结构表面错台量、同一环构件纵向错位量、前后环纵缝平面错位量等允许值，并与明挖现浇隧道、盾构隧道及装配整体式等结构的相关标准进行了对比分析。研究和实际工程应用证明：控制标准总体合理，可作为后续工程建设和相关标准制定的参考。构件制作精度对拼装精度的影响较大，提高构件制作精度，对提高拼装精度具有重要意义；自重压紧方式对控制隧道纵缝张开量最为有利，而控制张拉荷载、提高构件制作精度、控制施工累计误差等，可有效控制隧道环缝张开量；接头设置定位销棒并严格控制定位精度和预留空隙量，对控制结构表面错台量起到关键性作用。

Research and Formulation of Control Standard for Accurate Assembly of Open-Excavated Prefabricated Tunnel Structures

The research on and application of construction technology for open-excavated prefabricated tunnel structures in China is still in its infancy. The control standard of assembly accuracy is an important parameter for measuring and controlling project quality during the construction of prefabricated structures. A reasonable formulation of the standard is related to the safety, reliability, economic rationality, and practical operability of project construction. Through an analysis of the factors affecting assembly accuracy, a theoretical index was proposed and combined with the practical application of a project. After analysis and refinement of the normal distribution curve of the measured values, standards for the main control elements of the assembly accuracy for open-excavated prefabricated tunnel structures were developed, including the axis plane positioning deviation, elevation positioning deviation, component shape and attitude deviation, joint opening, structural surface dislocation, and longitudinal dislocation of the same ring. The permissible values of the plane dislocation of the front and rear circumferential longitudinal joints were compared with the relevant standards for open-excavated cast-in-place tunnels, shield tunnels, and prefabricated integral structures. Research and actual engineering applications have proven that the control standards are generally reasonable and can be used as a reference for engineering construction and the formulation of relevant standards. Component fabrication accuracy has a significant impact on assembly accuracy. The self-weight compaction mode was the most favorable for controlling the longitudinal joint opening of tunnels. The opening of the circumferential joint for tunnels can be effectively controlled by controlling the tensioning load, improving the accuracy of component fabrication, and controlling the cumulative error of construction. The positioning pin bar was set at the joint, and the positioning accuracy and amount of space reserved were strictly controlled and played a key role in the control structure and indicated the amount of platform staggering.