预应力混凝土衬砌张拉是盾构输水隧洞预应力衬砌施工的关键环节,现有张拉方法工序繁复,施工效率较低,难以进行合理的资源配置。本文以珠江三角洲水资源配置工程某输水盾构隧洞预应力衬砌区间为例,通过有限元数值模拟和现场施工工效对比,对预应力混凝土衬砌张拉施工方案进行优化。结果表明:采用一机两顶,单次张拉双侧2个锚具槽的优化方案不仅能够满足结构安全需求,整体变形相较于设计工况减小了28.04%,对结构变形的改善效果最好,并且施工时的张拉次数比设计工况减少了22次,经过现场施工工效对比,每个预应力混凝土浇筑节段张拉优化方案可节省张拉施工时间19.98 h,在保证结构安全的前提下显著提高了施工效率。研究结果可为类似工程提供参考。

The tensioning of prestressed concrete lining is the key link in the construction of prestressed lining of shield water conveyance tunnel. The existing tensioning methods are complicated and the construction efficiency is low, so it is difficult to carry out reasonable resource allocation. Therefore, based on the prestressed lining interval of a water conveyance shield tunnel in the Pearl River Delta Water Resources Allocation Project, the prestressed concrete lining tension construction scheme is optimized by finite element numerical simulation and on-site construction efficiency comparison. The results show that the optimization scheme of one machine with two roofs and two anchorage slots on both sides of a single tension can not only meet the structural safety requirements, but also reduce the overall deformation by 28.04% compared with the design conditions. The improvement effect of structural deformation is the best, and the number of tensions during construction is 22 times less than that of the design conditions. The optimized tensioning scheme of each prestressed concrete pouring segment can save the tensioning construction time by 19.98 h, which significantly improves the construction efficiency under the premise of ensuring the safety of the structure. The research results can provide reference for similar projects.