中文摘要：

针对大跨度悬索桥主缆的精细化分析中不能同时考虑主缆弯曲刚度、主缆初始弯曲、索鞍及缠丝等因素的影响,提出了一种新型的初弯曲梁单元来模拟主缆的弯曲刚度和初始弯曲,通过虚功增量方程推导其切线刚度矩阵,并编制了主缆非线性有限元程序,建立大跨度悬索桥主缆施工过程的有限元模型,计算中考虑了索鞍处主缆线形的修正及由缠丝引起的主缆弯曲刚度的变化。结果表明：弯曲刚度使主缆在恒载作用下的竖向变形减小,成桥状态时由此引起的主缆线形计算偏差没有超过工程精度的要求;成桥状态时靠近桥塔的吊索吊点处主缆的弯矩及弯曲应力显著,需要在大跨度悬索桥主缆设计和施工中加以考虑。

英文摘要：

Aiming at refined analysis of the main cable of long-span suspension bridge cannot take bending stiffness,original curve,saddle,wrapping and other factors into account simultaneously,a novel original curvature beam element is put forward to simulate the bending stiffness and original curvature of the main cable. Based on the virtual work increment equation,the tangent stiffness matrix for the original curve beam element is derived,and the nonlinear finite element program for the main cable is composed. The finite element model of the main cable of long-span suspension bridge under construction process is established,and the model includes the modification method for main cable shape at the saddle,and the variation of the bending stiffness caused by the main cable wrapping. The result shows that（ 1） the vertical deformation under dead load decreases when consider the bending stiffness,but the geometric shape deviation caused by the bending stiffness in the completion state meets the requirements of precision;（ 2） the bending moment and the bending stress of the main cable in the hanging point close to pylon are very significant in the completion state,which is needed to consider in the design and construction of the bridge.