悬索桥主缆纵桥向约束刚度研究

发布时间：2018-02-02 11:59

本文关键词： 桥梁工程悬索桥能量原理纵向刚度主缆　出处：《中国公路学报》2015年08期 　论文类型：期刊论文

【摘要】：为确定悬索桥主缆对桥塔的约束刚度,假定主缆线形为抛物线,通过变分原理获得主缆垂度改变与其跨长及水平力变化之间的关系。运用能量守恒原理,桥塔在活载作用下发生变形并引起主缆线形改变,与此同时,外力做功转化为结构重力势能及主缆的弹性应变能并提供对桥塔的约束作用,据此推导了主缆约束刚度解析表达式。为验证公式精度,建立悬索桥有限元模型进行验证,并与已有公式进行了对比,研究了边中跨比、中跨垂跨比以及主缆应力水平对边跨主缆纵向刚度的影响,给出了可直接用于估算边跨主缆刚度的相关图表。研究结果表明:采用提出的公式计算主缆初始切线刚度具有较高精度;忽略主缆的弹性变形对于中跨主缆刚度影响不大,对边跨主缆影响较大;边跨主缆的约束刚度与单位桥长恒载成正比,随着中跨垂跨比及边中跨比的减小而增大。
[Abstract]:In order to determine the restrained stiffness of the main cable of suspension bridge to the bridge tower, assuming that the main cable is parabola, the relationship between the variation of the sag of the main cable and the change of span length and horizontal force is obtained by the variational principle, and the energy conservation principle is used. At the same time, the external force work is transformed into the potential energy of the structure gravity and the elastic strain energy of the main cable and provides the constraint to the bridge tower. In order to verify the accuracy of the formula, the finite element model of suspension bridge is established and compared with the existing formula, and the ratio of side to middle span is studied. The effect of midspan vertical span ratio and stress level of main cable on longitudinal stiffness of side span main cable. A relative diagram is given to estimate the stiffness of the main cable directly. The results show that the proposed formula has a high accuracy in calculating the initial tangent stiffness of the main cable. Ignoring the elastic deformation of the main cable has little effect on the stiffness of the medium span main cable, but greater effect on the side span main cable. The constraint stiffness of the side span main cable is proportional to the dead load of the unit bridge length, and increases with the decrease of the midspan vertical span ratio and the side to middle span ratio.
【作者单位】：西安科技大学建筑与土木工程学院;同济大学桥梁工程系;长安大学公路学院;
【基金】：国家重点基础研究发展计划(“九七三”计划)项目(2013CB036303)
【分类号】：U448.25
【正文快照】： cable,which provided restriction effect for bridge tower.On this basis,an analytical expressionwas derived for the restraint stiffness of main cable.The formula was verified by a finite elementmodel for suspension bridge and compared with existing formul

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