【作者】 王晓明；

【导师】 郝宪武；

【作者基本信息】 长安大学 ， 桥梁与隧道工程， 2007， 硕士

【摘要】 近来,国内外相继兴建了多座自锚式悬索桥。由于结构形式上缆端部锚固力介入了梁体的受力和变形,施工工序上先梁后缆等特点,使得自锚式较地锚式悬索桥在静力和动力特性上都有很大不同。此外,空间索形缆索系统作为一种新形式,其每个缆段与桥轴线的夹角不同,吊杆为倾斜的。这使得吊杆必须考虑垂度效应,而且主缆、吊杆在线形与受力的求解中存在耦合。与传统平面索形相比,其复杂度显著提高。目前世界上已建成的空间索形自锚式悬索桥只有3座。本文正是立足于这些新问题,通过对缆索系统、塔梁系统的分析,解决了空间索形自锚式悬索桥初始平衡状态中的一系列问题,为后续的结构效应分析提供了完备的数据。首先,在回顾自锚式悬索桥计算理论和非线性影响因素之后,论文对自锚式悬索桥缆索系统计算进行研究。重点针对空间索形,详细引述了日本Ohtsuki博士的节线法和同济大学罗喜恒博士的弹性悬链线法,并对后者的程序实现作出进一步研究,给出重要参数:吊杆下端竖向力和修正值的求解方法,形成了弹性悬链线求解空间索形的算法。其次,根据本文算法,利用MATLAB语言编制了程序SASB-IESA(自锚式悬索桥初始平衡状态计算程序)。利用本程序计算韩国永宗大桥,并与文献[34]对比,验证了本程序良好的精度。然后,论文研究指出:对于自锚式悬索桥,为了保证与设计成桥态的一致,必须在缆索系统张力之外,引入塔梁系统初内力来抑制塔、梁的变形,即缆索边界条件的变化,以实现初始平衡状态的零位移。论文详细讨论了初内力的计算迭代方法;零位移程序实现的方法;塔梁下料尺寸的计算方法。接着,利用SASB-IESA程序输出的数据,在MIDAS civil中建立成桥态模型,进行活载、特征值分析,并针对结构特性进行讨论。最后,论文以千米级地锚式悬索桥为算例,分别利用MIDAS civil建立平面索形与空间索形模型,对二者自振频率及振型进行对比,得到以下结论:在对竖向承载能力影响不大的情况下,缆索系统的横向承载能力得到显著提高,大大提高了整个桥梁的横向刚度和抗扭刚度。从而提高结构的动力稳定性。更多还原

【Abstract】 Recently,a number of self-anchored suspension bridges are constructed at home and abroad.Because cable anchorage forces influence stress and deformation of the girder,and the girder is constructed before the main cable,self-anchored suspension bridge has a large diffence with earth-anchored suspension bridge on static and dynamic characteristic.Furthermore,as a kind of new cable shape,spatial cable system have different angle between each cable segment and bridge axis.For its hangers are declining , sag effect have tu be taken into account.The main cable and the hanger couple together during solving process of shape and force.Spatial cable is more complex than plane cable configuration.At present,in the world there are only 3 self-anchored suspension bridges with spatial cable which have been in use.This paper bases on these new issue,analyses cable-hanger system and tower-girder system,solve a series of problem in the initial equilibrium state of the self-anchored suspension bridge with spatial cable and supply complete data for subsequent structure effect analysis.Above all,after reviewing computational theory and non-linear influential factor of self-anchored suspension bridge,the paper studies its cable-hanger system.Aiming at spatial cable,the paper quotes detailedly Japanese doctor Ohtsuki’s straight line segment theory and tongji university doctor Luo xi heng’s elastical catenary theory,and further studies the latter’s calculation method of programme. After presenting crucial parameters:solution method of the hanger lower end vertical force and adjusted values,elastical catenary algorithm of spatial cable is deduced.Secondly,according to the previous algorithm,using MATLAB language,the paper writes the programme called as self-anchored suspension bridge initial equilibrium state calculating programme(SASB-IESA).The Yongjong Grand Bridge is calculated with SASB-IESA.By comparing the analysis result with literature[34], SASB-IESA is demonstrated high accurate and efficient.Thirdly,the paper indicates that besides the cable-hanger system tension,self-anchored suspension complete bridge analysis model has to introduce the initial forces of the tower-girder system to suppress their deformations,so the current model satisfied not only the target design configuration but also the self-equilibrium between the full dead loads and internal member forces. The paper propose iterative method of the initial forces and zero displacement, calculation method of tower and girder’s zero-stress dimension.Then,the paper founds a complete state analysis model using MIDAS civil program with SASB-IESA’s output data and makes structure effect analysis.At last,the paper takes a kilometer level earth-anchored suspension bridge as an example,founds separately plane cable and spatial cable analysis modle using MIDAS civil program,compares respectively their natural vibration frequency and mode,obtains following conclusion:spatial cable advances obviously the whole bridge’s transverse stiffness and torsional stiffhess,improving structural dynamic stability.更多还原