【作者】 赵俊伟；

【导师】 谢肖礼；

【作者基本信息】 广西大学 ， 固体力学， 2008， 硕士

【摘要】 矮塔斜拉桥的结构主要由塔、梁、索和墩组成。这种桥是近年来兴起的一种新型桥梁结构形式,它的总体特点是塔矮、梁刚、索集中布置,属于高次超静定结构。矮塔斜拉桥具有斜拉桥的形式,但在布索、结构尺寸比例以及受力特性等方面又与真正的斜拉桥有明显的差别,是介于具有非常柔性加劲梁的斜拉桥和梁高比较大的连续梁式桥之间的一种过度性桥梁,不仅结构体系多变,而且具有刚柔相济的结构特点,受力性能介于连续刚构桥和斜拉桥之间。目前,国内外对其动力性能的研究较少,尤其是对双索面宽幅矮塔斜拉桥的动力特性和地震反应特性的研究还是空白。研究该新型桥梁体系的动力特性和地震反应特性,为其抗震设计提供依据和参考,是一项很有意义的工作。本文以国内首座桥面宽达41米的双索面宽幅预应力混凝土矮塔斜拉桥为研究对象,建立双索面宽幅矮塔斜拉桥基准桥空间有限元模型,根据该桥梁体系主要设计参数的统计结果,选定7个设计参数作为动力特性参数变量进行动力特性参数敏感性分析,7个参数分别是支承条件、拉索间距、主塔高跨比、主塔截面刚度、边主跨比、主梁高跨比和斜拉索截面面积,并通过索、塔参数动力影响度定量分析双索宽面幅矮塔斜拉桥的动力特性。研究结果表明:双索面宽幅矮塔斜拉桥的动力特性比较接近宽幅的连续刚构桥,索、塔参数对主梁动力特性的影响较小,支承条件、边主跨比、主梁高跨比和主塔高跨比参数变化对结构动力特性的影响较大。在动力特性研究结果的基础上,本文选取边主跨比、主梁高跨比和主塔高跨比三个参数进行实际地震波一致输入地震反应分析,分析研究结果表明:双索面宽幅矮塔斜拉桥在实际地震波作用下地震反应出现空间藕联性,索和塔的存在使得双索面矮塔斜拉桥的地震反应对体系参数变化反映较为敏感,有些情况下,索、塔放大地震反应,有些情况下却有减小地震反应的作用,参数变化对双索面宽幅矮塔斜拉桥地震反应的影响规律不同。更多还原

【Abstract】 The main component parts of dwarf tower cable-stayed bridge are the main tower, beam,cable and pier.This bridge is a new bridge structure,rise in recent years,the general characteristics of it are dwarf tower and cable layout,belonging to the ultra-high fixed structure.Wide deck and dwarf-tower double cable-stayed bridge has the form of a cable-stayed bridge,but in layout of cable,structure size and the characteristics of force have clear difference from real cable-stayed bridge.Wide deck and dwarf-tower double cable-stayed bridge is an over-bridge which is between cable-stayed bridge and the rigid frame bridge,which not only have changefully structure system,but also the structural have rigid and flexible characteristics.By now, the static performance of this new style bridge system was studied deeply and widely, but dynamic behaviors were seldom studied.When it comes to system dynamic analysis of Double dwarf-tower wide cable-stayed bridge,it was none,therefore,studying on dynamic characteristics and seismic response performances for wide deck and dwarf-tower double cable-stayed bridge,and making proposition and reference to the earthquake resistance design are a important and significative work.The study of this paper is a domestic wide deck and dwarf-tower double cable-stayed bridge.Data about dwarf-tower cable-stayed bridge are collected and analyzed firstly,and the range of every parameter’s value is decided.Then,seven parameters are selected for dynamic analysis.These parameters include the coupling mode between girder and pier,the space between adjoin stay cables,the ratio between height of tower and length of main span,section rigidity of tower,side to main span ratio, the ratio between height of girder and length of main span,and the total section area of cables.After dynamic analysis,use influence degree of pylons and cables to reflect the influence of cables and pylons on the dynamic behaviors.The study results indicated that dynamic characteristics of wide deck and dwarf-tower double cable-stayed bridge with girder fixing with the towers and the piers are more like characteristics of continuous beam bridge than ordinary cable-stayed bridge.Pylons and cables less influence main beam’s dynamic characteristics,the coupling mode between girder and pier,the ratio between height of tower and length of main span,side to main span ratio, the ratio between height of girder and length of main span more influence main beam’s dynamic characteristics.Based on dynamic analysis,parameters include the ratio between girder and pier,side to main span ratio and the ratio between height of pylon and length of main span were analyzed to find out the characteristics of seismic response. The study results indicated that seismic response of wide deck and dwarf-tower double cable-stayed bridge is very sensitive to parameters.The conclusions of this paper are valuable reference for further understanding of the dynamic properties of wide deck and dwarf-tower double cable-stayed bridge.Some conclusions and suggestions for anti-seismic design are presented in this paper.更多还原