English：

This paper aims to investigate the significant impacts of geometric initial defects and initial stress on the internal forces and stresses of arch bridge structures with arch ring axis. Based on actual engineering cases, four finite element models were established, which divided into two groups. One group included two models that consider the influence of geometric initial defects of the arch axis; The other group also included two models, considering the geometric initial defects of the arch axis first and then simulating the effect of initial stress. Both groups compared the internal forces and stresses of the arch bridge structure. The results show that geometric initial defects have a small effect on the axial force of the arch ring, with an increase of less than 1%. However, they have a significant impact on the bending moment and stress distribution of the arch ring, especially at the top of the arch. At the arch top, the bending moment decreases by up to 91.31%, while at the arch base, it increases by 17.03%. Additionally, the concrete stress on the arch base and upper edge increases by 23.19%, while the stress on the lower edge decreases by 51.95%. After considering the effect of initial stress, the distribution of internal forces in the arch bridge significantly changes. The axial force at the arch base increases by 65.5%, and the maximum bending moment of the arch ring decreases by 68.21%. The stress on the upper edge of the arch ring section increases by up to 113.7%. Therefore, whether it is finite element modeling analysis or design during the actual construction phase, it is crucial to fully consider the influence of geometric initial defects of the arch axis and accurately simulate the presence of initial stress according to the actual construction sequence.