【作者】 梅盖伟；

【导师】 周水兴；

【作者基本信息】 重庆交通大学 ， 桥梁与隧道工程， 2009， 硕士

【摘要】 近年来我国大跨径拱桥得到迅速发展,主拱安装除少数采用转体施工法和整体提升法施工外,绝大多数采用无支架缆索吊装斜拉扣挂法。扣索索力与节段预抬值的计算是无支架缆索吊装施工控制的关键。目前国内针对缆索吊装法已经提出不少索力与节段预抬量计算方法,但普遍存在松索成拱后主拱出现马鞍形的问题;同时,在建立有限元模型时,忽略了扣塔的影响,使计算结果与实际有较大差异。为此,本文提出了基于裸拱变形为控制目标的索力计算新方法,建立集拱肋、扣塔、扣索和背索于一体的有限元模型,以此来计算扣索索力与节段预抬量。主要内容如下:1、分析了以往计算方法存在的问题,介绍拱肋松索成拱后出现马鞍形的原因,在此基础上提出负预抬值的拱肋节段预抬量设置方法;2、提出基于裸拱变形为控制目标的拱肋整体安装索力计算方法和拱肋分肋安装索力计算方法;3、研究多肋拱桥横向偏位产生的原因,分析出肋间高程差将引起拱轴线横向偏位,推导出肋间高程差与拱轴线横向偏位的几何关系;4、分析了扣塔偏位对拱肋节段标高的影响,推导了扣塔横向位移造成拱肋标高变化关系的公式;5、基于ANSYS的APDL语言,编制了大跨度钢管混凝土拱桥施工控制专用程序,开展了两座在建钢管混凝土拱桥——小河特大桥和新龙门大桥的扣索索力和节段预抬量。实践表明,本文提出的方法和编制的程序是正确的,实测索力与理论索力吻合良好,松扣后的拱轴线形与裸拱变形基本一致,克服了拱肋马鞍形的出现。更多还原

【Abstract】 Recent years, long-span arch bridge has been rapidly developed,in China.The installation method of the main arch is mainly cable-stayed suspension method,except a small number remain using body rotating method and integral lifting method.The calculation of cable force and camber capacity is the key to the cable erection without trestle in construction control.There are many calculation method about cable force value and pre-camber capacity for cable hoisting method,but a problem appears when close the arch after releasing cable;At the same time,when set up the finite element model,many neglect the impact of tower,that results in the calculation results have great difference with the actual.Therefor,the thesis propose a new cable force calculation method based on the goal of bare arch deformation,and set up finite element model including arch rib,tower,cable and back cable,in order to calculate the cable force and camber capacity.The main content is as follows:1. Analyse the problem of previous calculation methods, introduce the reason when close arch after releasing cable,and put forward the method of elevating arch rib segment by negative camber on this basis.2. Propose a cable force calculation method based on the goal of bare arch deformation by overall installation and sub-installation of arch rib.3. Research the reason of horizontal deviation in the multi-ribbed arch bridge, obtain the results by analysis that elevation difference of arch rib will cause arch axis horizontal deviation,and deduce the geometric relationship between elevation difference of arch rib and horizontal deviation of arch axis.4. Analyse the effects of tower deduction to the elevation of arch rib segment, and derive the formula about tower deduction to the elevation of arch rib segment.5. Based on the ANSYS APDL language,write program about construction control of long span concrete-filled steel tubular arch bridge,carry out the cable force and camber capacity calculation for concrete-filled steel tubular arch bridge—Xiaohe Bridge and the Xinlongmen Bridge.Practice shows that the method proposed and the program are right,the measured cable value and theoretical value are in good agreement,arch axis after releasing cable is basically same with bare arch deformation,overcome the appearance of saddle-shaped arch rib.更多还原