【作者】 张洪金；

【导师】 邱文亮；

【作者基本信息】 大连理工大学 ， 桥梁与隧道工程， 2004， 硕士

【摘要】 自锚式悬索桥由于省去了庞大的锚碇，相对降低了造价，外形也比较美观，因此越来越受到人们的青睐，成为城市市区中小跨径桥梁极具竞争力的方案。本文在总结国内外相关文献的基础上，对混凝土自锚式悬索桥的静力性能和动力性能进行了较为系统的分析，并结合一座正在建设的混凝土自锚式悬索桥的模型试验对理论计算进行了验证，主要结论如下： (1) 以抚顺市万新大桥为背景，研究了混凝土自锚式悬索桥的静力性能，分析比较了混凝土自锚式悬索桥与地锚式悬索桥的差别，自锚式悬索桥的跨中弯矩和挠度均比地锚式悬索桥的要大一些，这主要是因为自锚式悬索桥主梁中存在着巨大的轴向压力，从而降低了主梁的刚度。弹性理论和非线性有限元模型计算结果比较接近，对于中小跨径的自锚式悬索桥，弹性理论完全可以进行设计计算和分析。混凝土的收缩、徐变对结构的影响比较明显，主梁的跨中挠度和弯矩均与主跨矢跨比、主梁拱度、主缆和吊索的弹性模量成反比，增大加劲梁的抗弯惯性矩能有效减少主梁的跨中挠度，但同时也使主梁跨中的弯矩大大增加。 (2)基于有限元原理，建立了万新大桥的动力计算模型，给出了万新大桥的前20阶频率和相应的振型。从结果来看，该桥的自振周期较长，第一阶振型对应的周期达到了2.19秒，体现了悬索桥的柔性结构的特性。与同一跨径和结构参数的地锚式混凝土悬索桥相比，混凝土自锚式悬索桥的自振周期略长一些，说明自锚式体系要比同样结构参数的地锚式体系的刚度要小一些。用反应谱法计算了万新大桥的地震反应，计算结果表明，竖向地震分量对结构的影响较大。 (3) 以万新大桥实桥为基础，于大连理工大学桥梁工程研究所实验室制作了1∶40的试验模型。对试验模型进行了静力试验和动力试验，试验结果与理论计算吻合较好，验证了理论计算中的各种模拟与假定的正确性。同时试验也表明：对于中小跨度的混凝土自锚式悬索桥，在成桥状态，受力行为基本是线弹性的，可以用线弹性理论进行分析。研究结果可用于指导实桥的设计和施工。更多还原

【Abstract】 With no large anchor and its lower cost, self-anchored suspension bridge(SASB) is now catching more attention by its elegant shape. It has become a competitive design scheme in middle-, and small-span bridges in cities. Based on the documents at home and abroad, the static force performance and dynamic behavior of concrete self-anchored suspension bridge(CSASB) are systematically investigated in this paper. At last, theoretical calculation is proved by model experiment of a CSASB being constructed. The main conclusion covers the following aspects:(1) Based on Wanxin Bridge in Fushun city, the static force performance of CSASB is analyzed. The difference between SASB and earth-anchored suspension bridge(EASB) is revealed.in this paper. Bending moment and deflection at the span midpoint of SASB are greater than those of EASB. The reason is that the great axial pressure in the main beam of SASB decreases its stiffness. The result calculated with elastic theory is similar to the result calculated with finite element model. Elastic theory is applicable to middle-, and small-span SASB. The infection by shrink and creep of concrete is obvious. Bending moment and deflection at the span midpoint are inversely proportional to rise-span ratio, camber and inertia moment of main girder. Enhancing the inertia moment of main girder will decrease the deflection at the span midpoint; however, it will increase the bending moment of the span midpoint at the same time.(2) Based on Finite Element Method, the dynamic computation model of Wanxin Bridge is set up. The first 20 frequencies and corresponding vibration modes of Wanxin Bridge are given. According to the result, the natural period of vibration of this bridge is long. This proves the suppleness of suspension bridge. The natural period of vibration of SASB is longer than that of EASB with the same span and structure parameters. This indicates that the stiffness of SASB is less than that of EASB with the same span and structure parameters. The seismic r esponse o f Wanxin B ridge i s a nalyzed w ith t he R esponse S pectrum M ethod. T he result indicates that vertical vibration has a strong influence on the bridge.(3) Based on Wanxin Bridge, an experiment model with a scale of 1:40 was made in bridge laboratory of Institute of Bridge Engineering, Dalian University of Technology. Static test and dynamic test were carried out on the model. The result of experiment coincides well with that of theoretical computation. Thereby the simulations and presuppositions are correct in theoretical calculation. At the same time, the result of experiment also indicates that the mechanic performance of CSASB in middle-, and small-span presents linear elasticity in finished state, and linear elastic theory is applicable to CSASB. The research in this paper is useful to direct design and construction of such kind of bridges.更多还原