节点文献

三主桁三索面斜拉桥内力横向分配与桥型特点研究

Tr Ansverse Distribution&Structur Al Behavior of Cable-Stayed Bridge with Three-Planes Truss&Cable

【作者】 易炳疆

【导师】 秦顺全;

【作者基本信息】 西南交通大学 , 桥梁与隧道工程, 2013, 硕士

【摘要】 三主桁三索面斜拉桥是近年出现的新颖桥型,与两主桁两索面斜拉桥相比,其空间性能突出,结构内力横向分配复杂,两主桁结构的某些力学特性在该类结构中不再适用。目前国内外主要对两主桁斜拉桥和三主桁梁桥作了部分研究,而针对三主桁三索面斜拉桥的研究略显欠缺,因此有必要对三主桁三索面斜拉桥进行受力性能研究。为了便于对称分析三主桁三索面斜拉桥的力学性能,本文所有分析结果均基于斜拉索零初拉力条件下,即通过力学推导和数值仿真模拟相结合的方法探讨了三主桁三索面斜拉桥在自重作用下的内力横向分配原理,并对该类桥型的结构特点作了阐述,具体工作如下:(1)分析了三主桁三索面斜拉桥横向三索面索力在自重作用下的分配规律。利用MIDAS/CIVIL建立自定义有限元模型,分别分析拉索线刚度、横梁横联刚度、节点刚度等因素对三索面索力横向分配的影响;(2)利用势能最小值原理对上述规律进行分析。首先简要介绍针对三主桁梁桥的空间分析薄壁箱梁法和两次分配法,然后利用势能最小值原理推导简化的三索杆件结构的索力表达式,并将其计算结果与有限元计算结果进行对比,阐述其横向受力原理;(3)在已建三主桁三索面斜拉桥有限元模型的基础上,分别建立了三主桁梁桥和两主桁两索面斜拉桥模型,首先对比分析了自重作用下三主桁三索面斜拉桥与三主桁梁桥的内力横向分配的影响因素,并总结了两者在简化计算方法上的异同,然后分析了三主桁三索面斜拉桥与两主桁两索面斜拉桥在结构性能上的异同,最后总结了三主桁三索面斜拉桥的桥型特点;(4)基于沪通长江大桥的有限元模型,计算了该桥自重作用下的主桁杆件内力与三索面索力的横向分配情况,并简要分析了沪通长江大桥在温差荷载、横风荷载和支座沉降等3种典型荷载作用下的结构内力分布情况。

【Abstract】 The cable-stayed bridge with three-planes truss and cable is a new type of bridge appeared in recent years.Compared with the two-planes cable cable-stayed bridge,many differences do exist,such as more-obvious spatial performance and more-complicated transverse distribution,so that most of the structural behavior cannot be shared between the two bridge styles.At present, at home or abroad,researches are mainly done on the three-planes truss beam bridge and two-planes truss cable-stayed bridge,insufficiently on two-planes truss and cable cable-stayed one. So it is necessary to study deeply on the mechanical performance of the new type of bridge.To facilitate symmetry analysis on the mechanical performance of three-planes cable-stayed bridge,all results are based on the condition of no initial tensile stay cables.That is,through the method of combination of mechanics derivation and numerical analysis,the mechanical principle of the three-planes truss cable-stayed bridge under dead weight was discussed, the structural behavior clarified as well.The work was done as follow:(1) The distribution regularity of stay cables’tension of the three-planes truss cable-stayed bridge under dead weight was analyzed.A self-defining finite element model was established by midas/civil,which was used to analyse the factors that affect the transverse distribution of stay cables’tension, such as the stiffness of stay cables, cross beams Joints and so on.(2) Based on the principle of minimum potential energy, relatively reasonable explanation was provided for the regularity summarized previously.The stay cable’s tension expression of a simplified model of three-planes truss cable-stayed bridge’s cross section was established based on the theory of principle of minimum potential energy,then compared its results with those from FEM to analyse its mechanical principle. Meanwhile, thin-wall box girder method based on spatial analysis and two-times distribution method of three-planes truss beam bridge were briefly introduced as well.(3) Based on the previously established model by midas,models of three-planes truss beam bridge and two-planes cable cable-stayed bridge were established separately.For the first, comparative analysis of transverse distribution and simplified calculation method between beam bridge and cable-stayed one with three-planes truss was given.For the second, comparative analysis of the performance was done between two-planes and three-planes cable cable-stayed bridge.And finally, the structrural behavior of cable-stayed bridge with three-planes truss and cable was summed up systematically.(4) Using the finite element model established by ANSYS,the situation of transverse distribution of internal forces of Hutong Yangtze river bridge trusses’bars and stay cables under self weight was clarified,and also, its internal force’s distribution under three typical loads of temperature,transverse wind and support settlement were briefly analysed.

节点文献中: 

本文链接的文献网络图示:

本文的引文网络