独塔自锚式悬索桥吊索力影响参数敏感性分析*

为了解成桥吊索力对构件刚度、索鞍位置、温度、吊索张拉力等参数的敏感性，保证自锚式悬索桥体系转换能够安全顺利地完成，以天水市罗家沟大桥为工程背景，采用解析法修正空缆线形、有限元法模拟施工过程，分析张拉前参数和张拉过程参数变化对成桥吊索力的影响。结果表明:刚性吊索索力对吊索抗拉刚度变化敏感，在实际施工前可根据实测数据对吊索张拉力进行适当调整；中、长吊索索力对张拉时环境温度比较敏感，中、长吊索临近的吊索索力对第1轮吊索的张拉力偏差比较敏感，在实际施工时应采取相应的措施对张拉力予以精确控制；吊索力对散索鞍沿滑动面滑动的边界处理较敏感，应在有限元建模和施工时予以重视。

Sensitivity analysis on influencing parameters of hanger cable force for single tower self anchored suspension bridge

To understand the sensitivity of the hanger cable force in the finished bridge state to the influencing parameters,such as member stiffness,saddle position, temperature,tension force of hanger cable,etc.,and ensure that the system transformation of self anchored suspension bridge can be completed safely and smoothly,the Luojiagou bridge in Tianshui city was taken as the engineering background.The analytical method was used to modify the empty cable shape,and the finite element method was used to simulate the construction process.The influence of the change in the parameters before the stretch draw and during the stretch draw process on the hanger cable force in completed bridge was analyzed.The results showed that the rigid hanger cable force was sensitive to the variation of tensile stiffness of the hanger cable,and the tension force of hanger cable could be adjusted properly according to the measured data before the construction.The medium and long hanger cable forces were more sensitive to the ambient temperature during the stretch draw process.The adjacent hanger cable forces of medium and long hanger cables were more sensitive to the stretch draw force deviation of the first round hanger cable,so the corresponding measures should be taken to control the stretch draw force precisely during the actual construction.The hanger cable force was more sensitive to the boundary treatment of the splay saddle sliding along the sliding surface,which should be paid attention to in the finite element modeling and construction.