Abstract: The hingeless arch is widely used due to its simple structure and good stability, the cable-arch structure formed by introducing prestress on the bare arch can further optimize the structural efficiency. However, most of the existing researches are focused on the hinged arch, which limits the popularization and application of the cable-hingeless arch structure. Based on the distribution law of the bending moment of the hingeless arch under the uniform load, the prestress design method of the cable-hingeless arch structure was studied by the equivalent load method; the mechanic properties of cable-hingeless arch structure and the hingeless arch were compared and analyzed. Aiming at the phenomenon that the bending moment of the skewback of cable-arch structure increased greatly, the construction method of change from hinge support to fixed support and reverse correction of manufacturing alignment was proposed. By comparing and analyzing the static performance of the cable-hingeless arch structure with change from hinge support to fixed support and the corresponding bare arch structure, the internal force optimization law of the prestress on the hingeless arch was clarified. It is found that the prestress of the cable-hingeless arch structure mainly optimizes the bending moment of the structure under the action of dead load, and the stability of the structure under the half-span load is much lower than that under the full-span load.

Key words: bridge engineering, cable-hingeless arch structure, prestress design method, change from hinge support to fixed support, static performance, stability

摘要： 无铰拱因构造简单、稳定性好而应用广泛，在裸拱上引入预应力形成的索-拱结构可进一步优化结构效能，但现有研究大多针对有铰拱，从而限制了无铰索-拱结构的推广应用。基于无铰拱在均布荷载作用下的弯矩分布规律，利用等效荷载法研究了无铰索-拱结构的预应力设计方法，并对比分析了无铰索-拱与无铰拱的力学性能；针对索-拱结构拱脚弯矩增大幅度较大的现象，提出了先铰支后固支与反向修正制造线形的施工方式；通过对比分析先铰支后固支无铰索-拱结构与对应裸拱结构的静力性能，厘清了预应力对无铰拱的内力优化规律，发现无铰索-拱结构的预应力主要优化了结构在恒载作用下的弯矩，且结构在半跨荷载作用下的稳定性远低于全跨荷载。

关键词: 桥梁工程, 无铰索-拱结构, 预应力设计方法, 先铰支后固支, 静力性能, 稳定性