李宏江. PC斜拉桥辅助墩拉力摆断裂的成因分析[J]. 工程力学, 2010, 27(增刊I): 210-215.
引用本文: 李宏江. PC斜拉桥辅助墩拉力摆断裂的成因分析[J]. 工程力学, 2010, 27(增刊I): 210-215.
LI Hong-jiang. FRACTURE CAUSE ANALYSIS OF TENSION ROCKER BEARING CABLES AT SUBSIDIARY PIERS IN A PRESTRESSED CONCRETE CABLE STAYED BRIDGE[J]. Engineering Mechanics, 2010, 27(增刊I): 210-215.
Citation: LI Hong-jiang. FRACTURE CAUSE ANALYSIS OF TENSION ROCKER BEARING CABLES AT SUBSIDIARY PIERS IN A PRESTRESSED CONCRETE CABLE STAYED BRIDGE[J]. Engineering Mechanics, 2010, 27(增刊I): 210-215.

PC斜拉桥辅助墩拉力摆断裂的成因分析

FRACTURE CAUSE ANALYSIS OF TENSION ROCKER BEARING CABLES AT SUBSIDIARY PIERS IN A PRESTRESSED CONCRETE CABLE STAYED BRIDGE

  • 摘要: 预应力混凝土斜拉桥辅助墩设置的拉力摆是用来抵抗使用阶段荷载产生的负反力,是保持预应力混凝土斜拉桥结构受力体系的关键构件。以天津永和大桥为背景,从桥梁的施工期和后期维修过程入手,建立整体分析的平面杆系有限元模型,以桥面线形、索力及塔位等实测结果对计算模型的有效性进行检验和修正,获得基准计算模型,以此分析拉力摆的受力情况及其变化规律,剖析了该桥辅助墩拉力摆断裂的最可能原因。结果表明:原竣工时的成桥状态下,主梁与辅助墩之间的压力储备有所不足,而钢丝的锈蚀和疲劳是造成拉力摆断裂的根源,严重超载则加剧了这一破坏过程,而后期维修加固措施却不是造成拉力摆断裂的原因。基于拉力摆的受力特点及其断裂成因分析结果,给出了恢复拉力摆的设计要点和养护维修建议。

     

    Abstract: In some prestressed concrete cable stayed bridges, the tension rocker bearing cables were provided at each subsidiary pier to resist a negative reaction force caused by service loadings. The tension rocker bearing cables were important members remaining the designed structural system of a bridge. Based on Yonghe Bridge of Tianjin in China, its construction stages and later maintenance processes are analyzed, and then a plane fi-nite-element model used for analyzing global effects of the bridge is established. The calculation results are com-pared with measured results, including the current geometry of bridge deck, cable forces and the inclined dis-placement at the top of towers. And then the model is checked and modified. Finally, an effective and corrective model is obtained. The model is used to calculate the axial force at tension rocker bearing cables. Thus, some fracture causes of tension rocker bearing cables are analyzed and identified. Results show that, the insufficient compression reservation between its main girder and subsidiary piers exists at its original finished dead stage. Moreover, the steel wire rust corrosion and fatigue are the essential fracture causes. Besides, the overloading ac-celerates the fracture process, but later maintenance or strengthening measures contribute little to fracture. Based upon these causes, some design advice for the rehabilitation of tension rocker bearing cables and later mainte-nance suggestions are presented.

     

/

返回文章
返回