Liu Zengwu, Zhou Shuixing, Zou Kairan, Qu Yinghao
School of Civil Engineering, Chongqing Jiaotong University, Chongqing, 400074, China.
Sci Rep. 2022 Jul 21;12(1):12451. doi: 10.1038/s41598-022-15755-w.
It is difficult to calculate the buckle cable force for the cantilever casting concrete arch bridge. Relying on the 180 m-span Jiming Sansheng Bridge, this paper put forward one method to calculate the initial buckle cable force based on the stress balance method. Firstly, the stress balance equation considering only tensile stress was derived for the first time, and the feasible region of the initial cable force was calculated by the allowable tensile stress of the arch rib, which improved the original stress balance method. Then, using the influence matrix, the initial buckle cable force was optimized by reducing the allowable tensile stress of concrete in stages, and finally the optimal initial cable force was obtained. The practical engineering results show that it is feasible to calculate the initial buckle force. The maximum tensile stress of concrete arch during the cantilever casting process is 1.52 MPa, meeting the specification requirements. The deviation between the calculated and measured stress is less than 12%. The calculated cable force agrees with the measured cable force, and the deviation is less than 2%. The initial cable force is only tensioned once, improving work efficiency. The method and experience of this paper can provide a reference for the arch bridge constructed by cantilever casting.
对于悬臂浇筑混凝土拱桥,扣索索力计算较为困难。依托180米跨径的鸡鸣三省大桥,本文提出一种基于应力平衡法的初始扣索索力计算方法。首先,首次推导了仅考虑拉应力的应力平衡方程,通过拱肋的允许拉应力计算出初始索力的可行域,对原应力平衡法进行了改进。然后,利用影响矩阵,通过逐步降低混凝土允许拉应力对初始扣索索力进行优化,最终得到最优初始索力。实际工程结果表明,计算初始扣力是可行的。悬臂浇筑过程中混凝土拱的最大拉应力为1.52兆帕,满足规范要求。计算应力与实测应力偏差小于12%。计算索力与实测索力相符,偏差小于2%。初始索力仅张拉一次,提高了工作效率。本文的方法和经验可为悬臂浇筑拱桥施工提供参考。