中文摘要：

为深入探寻多塔斜拉桥刚度特征,将斜拉索对桥塔的约束比作弹簧刚度这一理念引入多塔斜拉体系.选取多塔斜拉桥的最典型形式——三塔斜拉桥建立弹簧刚度等效模型,基于变形协调原理,求解多塔斜拉桥非边塔纵向抗推刚度,对推导的公式进行算例验证,并分析结构主要参数对桥塔纵向抗推刚度的影响.研究结果表明：对非边塔左跨施加均布荷载时,本文推导公式的非边塔塔顶偏位解与已有文献有限元解间的误差在6.82%以内,说明本文推导的非边塔纵向抗推刚度公式能够反映多塔斜拉桥桥塔的刚度特征,符合多塔斜拉桥概念设计的要求;非边塔纵向抗推刚度与桥塔自身刚度、主梁刚度、拉索与主梁夹角、拉索线刚度和桥塔拉索锚固间距等因素有关.

英文摘要：

In order to explore the stiffness characteristics of multi-tower cable-stayed bridges,the constraint to bridge towers caused by cables is compared to spring stiffness.We take the threetower cable-stayed bridge as research object,which is the most typical type of multi-tower cablestayed bridges.Firstly,the longitudinal anti-push rigidity of the non side tower of the three-tower cable-stayed bridge is solved based on the principle of deformation coordination.Secondly,the effectiveness of the derived formulas is verified by a calculation example.Finally,the influences of main parameters of the bridge structure on longitudinal anti-push rigidity of the left span of non side tower are analyzed.The results show that when imposing uniformly distributed load on thenon side tower,the errors between the deviation of non side tower roof solved by the side tower deformation formulas derived in this paper and the finite element solutions obtained from a previous study are within 6.82%.And it is illustrated that the proposed formulas is suitable for calculating the stiffness characteristics of multi-tower cable-stayed bridges,and can meet the requirements of the conceptual design.Meanwhile,the longitudinal anti-push rigidity of the non side tower for multi-tower cable-stayed bridges is related to tower stiffness,girder rigidity,angle between cable and girder,cable line stiffness and cable anchorage spacing of tower.