斜桥结构简化分析方法研究

论文总字数：33315字

摘 要

随着中国经济和社会的快速发展，高等级公路和城市立体交通建设也加速，近几十年来中国经济的快速发展使得道路网络建设速度加快，公路的等级也相应提高。而一些地区密布着水网、航运比较发达，使得高速公路或高速铁路在跨越河流和其它公路、铁路时，呈斜交状态。这时采用斜交桥型可以减小计算跨径，并且更加经济，由于斜交桥在公路铁路桥梁建设时得到越来越多的应用，有关斜板桥的设计方法的研究也逐渐增多。

本文根据1996年《公路桥梁设计手册》提出的整体式斜板桥内力简化计算方法，在新的桥梁规范对公路铁路桥梁的荷载作用的规定进行更新的情况下，对公路桥梁设计手册中建议的整体式斜板桥的简化计算方法的弯矩系数表进行了研究和计算。

使用有限元分析方法对跨度10m-30m常用跨度整体式斜板桥进行内力分析，斜交角范围，桥宽根据桥梁工程设计中常用的二车道，四车道，六车道双向行驶桥梁的规定选用。利用ANSYS软件进行有限元建模分析，计算整体式斜板桥分别在恒载和车辆荷载作用下的精确弯矩值和扭矩值，与简化计算方法等效的简支梁最大弯矩的计算结果进行比较，验算恒载作用的弯矩系数表，更新并改进整体式斜板桥常用桥型的活载弯矩系数表，最后给出恒载作用的完整弯矩系数表。

【关键词】整体式斜板桥；新桥规；有限元分析；斜板桥简化计算方法；弯矩系数表

Abstract

For the speedy development of Chinese society and economy, the construction of high-grade highways and urban multi-level transportation system has accelerated. The outstanding development of the economy of China leads to the construction of road networks speeding up. At the same time, the level of highways is also improved. In some areas where there are variegated rivers and lakes, shipping is always well developed. This phenomenon makes the highways and railroads skewed in order to cross other highways and railroads. By employing the structure of skewed bridges, the calculated span of bridges will diminish and it will be more economical to build bridges. As skewed bridges get used increasingly when designing highways and railway bridges, more study on the design of skewed bridges are carried out.

Based on the simplified analysis method of monolithic skewed slab bridges (recommended in highway bridges design manual,1996), considering the update of the rules of the load effect on highways and railway bridges in new standards, this paper carries out a study on the simplified analysis method recommended in the manual.

By using finite-element method, common-span monolithic skewed slab bridges are analysed in this paper. All bridges considered in this study were simply supported structures of two, four and six lanes, with spans ranging from 10 to 30 m. The selected skew angles varied from 0 to 60°. Through the finite-element analysis procedure of ANSYS software, accurate bending moments and torque of monolithic skewed slab bridges under dead and live load are defined. Compared with the results of maximum bending moments of simply supported beam, bending moment coefficients under dead loads are verified. Bending moment coefficients under live loads are updated at the same time. Finally, the detailed table of bending moment coefficients under dead loads is completed.

Keywords: Monolithic skewed slab bridges; New standards; Finite-element analysis;

Simplified analysis method; Bending moment coefficients

目 录

1 绪论······························································6

1.1国外研究现状·······················································6

1.2我国斜桥计算方法发展历程···········································8

1.3研究背景····························································9

1.4研究意义···························································9

1.5研究的目标和技术方法··············································10

2 斜板桥结构空间分析··················································12

2.1斜交板的受力特征···················································12

2.2理论计算方法······················································12

2.3 ANSYS建模说明·····················································15

3 恒载内力计算·······························································16

3.1建模和恒载系数计算················································16

3.2单元类型选择······················································23

3.3恒载作用弯矩系数计算示例··········································24

整体式斜板桥恒载作用弯矩系数表······································25

4活载内力计算································································29

4.1车辆荷载取值······················································29

4.2简化计算方法······················································30

4.3折算宽度法························································33

4.4建模和加载························································35

4.5活载弯矩系数表的补充计算··········································43

4.6活载作用弯矩系数表················································43

4.7活载弯矩系数表分析················································45

4.8 新老弯矩系数表对比················································46

4.9 新弯矩系数表的意义以及存在的问题··································47

4.9.1意义························································47

4.9.2存在的问题··················································48

4.10 网格划分研究····················································48

5 总结与展望································································50

5.1 总结······························································50

5.2 展望······························································51

致谢········································································53

参考文献····································································54

1 绪论

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