Determination of initial cable force of cantilever casting concrete arch bridge using stress balance and influence matrix methods

基于应力平衡和影响矩阵的混凝土拱桥悬臂浇筑初始索力确定方法研究（英文）

Cantilever casting concrete arch bridge using form traveller has a broad application prospect.However,it is difficult to obtain reasonable initial cable force in construction stage.In this study,stress balance and influence matrix methods were developed to determine the initial cable force of cantilever casting concrete arch bridge.The stress balance equation and influence matrix of arch rib critical section were established,and the buckle cable force range was determined by the allowable stress of arch rib critical section.Then a group of buckle cable forces were selected and substituted into the stress balance equation,and the reasonable initial buckle cable force was determined through iteration.Based on the principle of force balance,the initial anchor cable force was determined.In an engineering application example,it is shown that the stress balance and influence matrix methods for the determination of initial cable force are feasible and reliable.The initial cable forces of arch rib segments only need to be adjusted once in the corresponding construction process,which improves the working efficiency and reduces the construction risk.It is found that the methods have great advantages for determining initial cable force in cantilever casting construction process of concrete arch bridge.

采用挂篮悬臂浇筑法建造混凝土拱桥具有广阔的应用前景,然而确定合理的扣、锚索索力是混凝土拱桥施工过程中的难点问题.本文提出采用影响矩阵和应力平衡法确定悬臂浇筑混凝土拱桥施工阶段的初张索力.在混凝土拱桥悬臂浇筑施工过程中,建立拱肋关键截面的应力影响矩阵和平衡方程,以拱肋关键截面的容许应力为约束条件,确定各扣索的索力范围.进而,选取一组扣索力代入其应力平衡方程,采用迭代法确定合理的施工扣索力.最后,基于力平衡原理确定锚索力.工程应用实例表明,采用影响矩阵和应力平衡法确定悬臂浇筑混凝土拱桥的合理施工索力是可靠的.在施工过程中,拱肋节段的索力只需张拉一次,本文提出的方法提高了工作效率,降低了施工风险.