城市高架桥结构方案关键因素分析及发展构想

Critical Factor Analysis and Development Conceiving of Structural Schemes for Urban Viaducts

为对城市高架桥的规划和建设提供参考,在分析杭州市几座典型高架桥的基础上,总结城市高架桥结构方案的关键因素并预测其发展趋势。经分析,对于城市高架桥的整体尺度,建议将桥梁高度控制在10～14m;当桥梁基础地质情况较好(较差)时,桥梁跨径在20～30m(30～35m)较合适,桥梁高度与跨径比一般为1∶2.5～1∶3;梁高与跨径比一般为1∶10～1∶20。对于城市高架桥的结构形式,上部结构一般采用混凝土现浇连续箱梁;下部结构一般采用弧形墩或大悬臂柱式墩;结构体系一般采用先简支后连续体系、连续体系、连续-刚构体系等形式。城市高架桥将向造型更轻盈优美、结构更耐久、功能更丰富并且更能体现环保理念的方向发展。

To provide reference for the planning and construction of urban viaducts, the critical factors of the structural schemes for the viaducts are summarized and the development trends of the schemes are predicted on the basis of analysis of several typical viaducts in Hangzhou City. According to the analysis, for the overall dimensions of the urban viaducts, it is proposed that the height of the viaducts should be controlled within 10; 14 m. Where the geologic conditions for the foundations of the viaducts are good （poor）, it will be appropriate that the span length of the viaducts should be 20;30 m （30;35 m）. The height-to-span ratio of the viaducts should generally be 1 ： 2.5;1 ： 3 and the depth-to-span ration of the girders for the viaducts should be 1 ： 10 1 ： 20. For the structural types of the viaducts, the cast-in-situ concrete continuous box girders should be preferably used for the superstructures while the arc shape piers or the long cantilever column piers should be used for the substructures. The structural system for a viaduct may be the one that is simply supported first and made continuous late, the continuous system and/or the continuous and rigid-frame system. The urban viaducts will develop towards the more lightweight and aesthetic configuration, more durable structures, richer functions and also towards the direction that can better embody the environment protection conception.