【作者】 相其生；

【导师】 刘小燕； 韦成龙；

【作者基本信息】 长沙理工大学 ， 桥梁与隧道工程， 2007， 硕士

【摘要】 高墩大跨连续刚构桥因其受力明确、行车顺畅、施工技术成熟等特点而得到广泛采用。尤其在高桥墩的大桥中,因采用薄壁柔性墩适应各种作用,受到山区高速公路建设者的青睐。在薄壁高墩的结构中,由于施工等因素的影响,使墩的稳定性变的十分重要。理论设计的桥墩结构属压弯构件,但实际上,桥墩会有初始缺陷,加上其它因素的影响,墩的稳定性问题的分析更为复杂。本文以野三河大桥为工程背景,对变截面高墩自体稳定性、最大悬臂状态的稳定性及全桥稳定性进行分析。主要研究内容和成果有:在弹性极限内,利用Ritz法推导了双薄壁高墩连续刚构桥的变截面高墩和最大悬臂状态下的临界荷载计算公式,并编制了计算程序,为该类桥型的第一类稳定问题提供了一种快捷的计算方法。利用大型有限元软件ANSYS,对野三河大桥建立了最高桥墩、最大悬臂状态、成桥状态的空间有限元模型,进行了稳定性分析。分别考虑墩身有初始偏位、墩顶荷载有初始偏心、桥墩受风荷载、日照温差效应及挂篮跌落的影响,得出了各种缺陷对稳定性的影响规律。在计算中,分别讨论分析了混凝土收缩、徐变及温度荷载效应对结构整体稳定性的影响。对野三河大桥最不利荷载组合下的整体稳定性进行了分析,验算了野三河大桥不利荷载组合下的稳定性。以上结果,为野三河大桥的稳定性提供了理论保证,并为该类桥型稳定性及有初始缺陷桥梁的稳定性研究提供参考。更多还原

【Abstract】 The continual rigid frame bridge with high pier and long span was widespread used because of the feature : explicit about force;driving unimpeded;the mature technique of construction etc.Especially for the large bridge with high pier, it is favoured by the builder of freeway in mountainous area because of using flexibility of thin wall pier to adapt all kinds of effect.This pier belongs to compression-bending component in theoretical design,actually,the pier existing initial defect,adding other factor’s affects which made it’s stability more complex. Based the backgrounds on the Ye Sanhe Bridge, the article has analysised the high pier self-stability, the biggest cantilever state’s stability and the entire bridge’s stability. The main research content and the achievement include:In the limit of elasticity, it has inferred the critical load formua about variable cross-section high pier’s self-stability and the biggest cantilever state’s stability in continual rigid frame bridge of double thin wall and high pier by the Ritz method, and drawed up a calculate procedure which provided one quick computational method for this kind of bridge stable’s question.The large Finite Element Software ANSYS was used to analysis the stability about the Ye Sanhe bridge by establishing three-dimensional finite element model for the high pier, the biggest cantilever state and the finished bridge state.It has analysed the effect to the bridge’s stability which separately considered initial displacement of the pier,initial offset of the load on the top of pier,the impact of wind load , differenal temperature effect of the sunshine and suspended wagon droped, has obtained the rule how influence to the stable of bridge by each kind of flaw.In the calculation, it has discussed and analysised the effect of the bridge’s stability with thoughting the concrete’s shrinkage and creep and the temperature over the structure.It also has analysised the Ye Sanhe Bridge’s stability with the harmful combination of loads and cauculated the stability of the Ye Sanhe Bridge in the harmful combination of loads.The results provide the theory instruction for the problem of stability of the Ye Sanhe Bridge and the reference for the research to this kind of bridge’s stability and the bridge’s stability which considered the initial flaw.更多还原