中文摘要：

为解决初步设计阶段采用挠度理论模型进行多塔悬索桥静力计算时面临的非线性方程数量剧增和收敛性问题,基于单索理论提出了多塔悬索桥在最不利荷载工况下结构控制参数计算的简化模型。根据加劲梁对悬索桥结构整体刚度贡献的研究将挠度理论模型简化为仅由1个积分方程控制的单索模型;然后,根据桥塔的变形协调条件,建立了考虑跨间耦合受力的多塔悬索桥的简化计算模型;最后,以1座三塔四跨悬索桥为例,分别采用有限元法、基于挠度理论和单索理论的解析模型对6种活载工况进行了计算。结果表明：在活载控制工况下,2种解析模型的计算结果间差异很小;与有限元结果相比,简化模型计算所得的加劲梁位移及缆索内力的最大相对误差均在5%以内;提出的方法不仅形式简单还具有较高的精度,可用于大跨度多塔悬索桥的简化计算。

英文摘要：

To solve the problems of the dramatic increasing in the number of non-linear equations and its convergence by using deflection theory based model in static force calculation on multispan suspension bridges during preliminary design stage,a simplified model was proposed based on single cable theory to calculate the controlling structural parameters of multi-span suspension bridges under the most unfavorable load cases.According to the researches on the stiffening girder＇s contribution to the bridge＇s global stiffness,the deflection theory based model was simplified to the single cable model,which was only controlled by an integral equation.And then,combining the deformation compatibility condition of the towers,the simplified calculation model of multi-tower suspension bridge,which considering the coupling effect between the adjacent spans,was derived.Finally,taking a four-span suspension bridge with three towers asan example,three different methods,finite element method（FEM）,deflection theory based analytical model and the proposed model,were used to carry out comparative analysis under six live load cases.The results show that the differences between the calculation results of the two analytical models are very small,and the biggest relative errors of displacement of stiffening girder and internal force of the cable calculated by the proposed method are smaller than 5%compared with the results of the FEM.This illustrates that the proposed method not only has a simple form but also has a high accuracy,and can be used in the large-span multi-span suspension bridge＇s simplified calculation.