基于LINGO的连续刚构桥预应力钢束优化研究

发布时间：2018-03-15 04:08

本文选题：预应力混凝土连续刚构桥　切入点：lingo　出处：《昆明理工大学》2014年硕士论文　论文类型：学位论文

【摘要】：预应力混凝土连续刚构桥在结构体系上属于连续梁桥。预应力混凝土连续刚构桥既保持了连续梁桥无伸缩缝、行车平顺的特点,又有T型刚构桥不设支座、施工方便的长处,且有很大的顺桥向抗弯刚度和横桥向抗扭刚度,它利用高墩的柔度来适应结构由预应力混凝土收缩、徐变和温度变化所引起的变形,能满足特大跨径桥梁的跨越及受力要求,同时在一定条件下具有用料省、施工简便、养护费用低等优点。我国公路系统从20世纪80年代中期开始设计、建造连续梁桥,但在长期的设计实践中,由于结构分析的复杂冗长,虽然设计者主观上希望把结构设计的尽可能优,力图使结构轻巧、纤细、美观以达到经济适用的要求,但缺乏系统的理论指导桥梁结构设计和优化结构设计,结构的优化依靠人们积累起来的经验,带有很强的主观性和盲目性,且工作量大,费时费力,又无法保证方案的正确性。所以在大跨径PC连续刚构桥设计中,对主要参数进行优化研究是必要的。本文以丽香高速某预应力连续刚构桥为背景,以lingo优化软件为工具,对主梁设计参数的优化展开研究,主要完成以下工作： (1)介绍了国内外连续刚构桥的发展和研究现状,确定了优化变量与优化常量。连续刚构桥上部结构设计参数中,边中跨比,根部梁高的高跨比,跨中梁高的高跨比,梁底曲线幂次,施工阶段划分方式,主梁纵向钢束布置可作为优化变量,其余设计参量可作为优化常量。 (2)介绍了优化软件lingo的数学原理及使用方法。 (3)基于lingo软件,以主梁各离散单元的弯曲能量之和最小为目标函数,以满足施工阶段和使用阶段的截面应力要求为约束条件,优化得到各阶段所需张拉的预应力钢束。得出优化后截面应力更均匀,减少主梁用钢量等结论。
[Abstract]:The prestressed concrete continuous rigid frame bridge belongs to the continuous beam bridge in the structure system. The prestressed concrete continuous rigid frame bridge not only maintains the characteristics of continuous beam bridge without expansion joints and smooth running, but also has the advantage of the T-type rigid frame bridge without supporting and easy construction. And there are great flexural stiffness and torsional stiffness in the transverse direction, which can adapt to the deformation caused by the shrinkage, creep and temperature change of the prestressed concrete by using the flexibility of the high pier, and can meet the requirements of the span and force of the long-span bridge. At the same time, it has the advantages of saving material, simple construction and low maintenance cost under certain conditions. Since the middle of 1980s, continuous beam bridges have been designed and built in our country's highway system, but in the long term design practice, Because of the complexity of structural analysis, although the designer subjectively wants to make the structural design as best as possible, trying to make the structure light, slender, beautiful to meet the requirements of economic application. However, there is a lack of systematic theory to guide the bridge structure design and optimization structure design. The optimization of the bridge structure depends on the experience accumulated by people. It has strong subjectivity and blindness, and the workload is large and time-consuming and laborious. Therefore, it is necessary to optimize the main parameters in the design of PC continuous rigid frame bridge with long span. In this paper, a prestressed continuous rigid frame bridge with Lixiang high-speed is used as the background, and lingo optimization software is used as the tool. The optimization of the design parameters of the main beam is studied. The main work is as follows:. This paper introduces the development and research status of continuous rigid frame bridge at home and abroad, and determines the optimization variable and optimization constant. In the design parameters of superstructure of continuous rigid frame bridge, the ratio of side to middle span, the ratio of height to span of root beam, the ratio of height to span of span center beam, the ratio of height to span of the upper structure of continuous rigid frame bridge are determined. The power of the curve at the bottom of the beam, the division of the construction stage, the arrangement of the longitudinal steel beam of the main beam can be taken as the optimization variable, and the other design parameters can be taken as the optimization constant. The mathematical principle and application method of optimization software lingo are introduced. Based on lingo software, the minimum of bending energy of the discrete elements of the main beam is taken as the objective function, and the constraint condition is to meet the requirements of the section stress in the construction stage and the use stage. The prestressing steel strands which need to be tensioned in each stage are obtained by optimization. The conclusion is drawn that the section stress is more uniform after optimization and the amount of steel used in the main beam is reduced.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U448.23

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