大跨装配式应急公路钢桥方案设计与模糊层次比选

发布时间：2018-05-20 00:21

本文选题：桥梁工程 + 设计方案　；参考：《长安大学学报(自然科学版)》2017年02期

【摘要】：装配式公路钢桥在战时抢修、抗震救灾中桥梁修复与加固等应急工程中发挥了重要作用,但现有装配式公路钢桥最大理论跨越能力只有69m,导致部分交通要道的大跨度桥梁短时期无法修复,造成了巨大的经济效益和社会效益损失。为满足大跨度桥梁应急抢修的要求,以单跨90m装配式公路钢桥为研究对象,提出采用抗弯和抗扭性能较好的矩形钢管截面作为桁架构件的主要截面以提高结构的跨越能力,在继承原有研究成果的基础上设计了"321"型、"200"型矩形钢管桁架方案,创新性地设计了"600"型矩形钢管桁架方案和三角形桁架方案。在有限元建模分析的基础上,详细分析了4种设计结构方案在移动荷载作用下的最大位移、组合应力、用钢量及1阶稳定屈曲系数这4个关键指标各自的优劣。为了方便桥梁设计方案的比选,以桥梁设计的基本目标作为评价设计方案的影响因素,利用模糊数学和层次分析法分解评判指标体系,建立了运用二级模糊综合评价决策方法进行设计方案优选比较的指标体系和方法。最后,结合单跨90m装配式公路钢桥的4种设计方案,给出了模糊层次分析评价和设计方案优选的具体过程。研究结果表明:"600"型矩形钢管桁架方案所对应的判断结果矩阵中的元素值最大,说明该设计方案在力学性能、经济合理性、技术可行性、施工方便性等方面优势明显,为4个设计方案中的最优方案。研究成果可为后续大跨装配式公路钢桥的研制方案提供设计思路和技术参考。
[Abstract]:Prefabricated highway steel bridges have played an important role in emergency projects such as emergency repair and reinforcement of bridges in times of war and earthquake relief. However, the maximum theoretical span capacity of existing prefabricated steel bridges is only 69m, which leads to the failure to repair the long-span bridges of some major roads in a short period of time, resulting in huge loss of economic and social benefits. In order to meet the requirements of emergency repair of long-span bridges, taking the single-span 90m assembled highway steel bridge as the research object, the rectangular steel pipe section with good flexural and torsional resistance is proposed as the main section of the truss members to improve the span ability of the structure. The "321" and "200" rectangular steel pipe truss schemes are designed on the basis of inheriting the original research results, and the "600" rectangular steel pipe truss schemes and triangular truss schemes are designed innovatively. On the basis of finite element modeling and analysis, the four key indexes of the four design schemes under moving load, such as maximum displacement, combined stress, steel quantity and first-order stable buckling coefficient, are analyzed in detail. In order to facilitate the comparison and selection of bridge design scheme, the basic objective of bridge design is taken as the influence factor of evaluating the design scheme, and the index system of decomposition and evaluation by fuzzy mathematics and analytic hierarchy process (AHP) is used. The index system and method of optimal selection and comparison of design schemes by using two level fuzzy comprehensive evaluation decision method are established. Finally, combined with four design schemes of single-span 90m assembled highway steel bridge, the concrete process of fuzzy AHP evaluation and design scheme optimization is given. The results show that the element value in the judgement matrix of the "600" rectangular steel pipe truss scheme is the largest, which indicates that the design scheme has obvious advantages in mechanical performance, economic rationality, technical feasibility, construction convenience and so on. The optimal scheme for the four design schemes. The research results can provide the design idea and technical reference for the development scheme of the long span assembled highway steel bridge.
【作者单位】：长安大学公路学院;
【基金】：国家自然科学基金项目(51378068,51308056) 中央高校基本科研业务费专项资金项目(2014G1211002,2014G2210003) 交通运输部企业技术创新项目(2013315490060)
【分类号】：U448.36

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