摘要
钢管混凝土拱桥因受力性能好、施工方便、稳定性好、美观等诸多优点,成为了近年来发展最快的桥型之一。此外,钢管混凝土拱桥相对梁桥跨度更大,相对于悬索桥和斜拉桥经济性更好,是目前主跨300~500 m的主要建设桥型。然而传统大跨钢管混凝土拱桥设计中拱肋截面参数确定存在效率低及现有以造价为单目标的结构优化方法所得到结构的性能偏低等问题,基于此,平均单位长度拱肋造价和截面面内抗弯刚度被选取作为优化目标,建立了4管桁式钢管混凝土变截面拱肋的多目标优化模型,并利用NSGA-Ⅱ遗传算法进行了求解,实现了大跨度钢管混凝土拱桥拱肋造价和稳定性2个方面的优化。实例计算结果表明:NSGA-Ⅱ遗传算法可快速、准确地求解出钢管混凝土变截面拱肋以造价和抗弯刚度表征的Pareto最优解集,是该类组合结构多目标优化问题一种高效的求解手段;所得到的Pareto最优解集可供工程决策者和设计者快速选择出同时满足造价较低和抗弯刚度较大的最优拱肋截面参数,显著提高了设计效率和设计方案的合理性;拱肋截面面内抗弯刚度与结构整体竖向刚度及面内稳定性的相关性强,选择该参数作为表征结构性能的优化目标具有一定的合理性;优化后结构的面内刚度和稳定性均满足规范要求,同时造价大幅度降低,优化效果良好。
CFST arch bridge has become one of the fastest-growing bridge types in recent years due to its many advantages,such as good mechanical performance,convenient construction,good stability and beautiful appearance.In addition,CFST arch bridge has longer span relative to the beam bridge and is more economical than suspension bridge and cable-stayed bridge.It is currently the main construction bridge type with a main span of about 300-500 m.However,there are some obvious deficiencies in traditional design methodology of CFST arch bridges,including low efficiency in determining parameters of rib section and low performance of the post-optimized structure under the basic optimization that adopts cost as the only objective.Based on this,selecting both the average unit length cost of the arch rib and in-plane sectional flexural stiffness as the optimize objectives,a multi-objective optimization model for the 4-tube trussed CFST arch ribs with variable cross-section is established,which is solved by using the NSGA-Ⅱgenetic algorithm,thus,the optimization of the cost and stability of the arch ribs of long-span CFST arch bridge has been realized.The calculation result of a real bridge example shows that(1)the NSGA-Ⅱgenetic algorithm can acquire the Pareto optimal solution set of CFST arch ribs with variable cross-section in terms of cost and flexural stiffness quickly and accurately,indicating that NSGA-Ⅱis an effective means for this sort of multi-objective optimization problems associated with composite structures;(2)the obtained Pareto optimal solution set can provide the optimized parameters of the arch rib section for decision makers and designers that coordinates the conflict objectives of cost and structural performance,which significantly improve the design efficiency and rationality of the design scheme;(3)there is a strong correlation of in-plane flexural stiffness of arch rib section with overall vertical stiffness and in-plane stability of the bridge,thus it is reasonable to select the in-plane sectional flexural stiffness as the optimize object;(4)the in-plane stiffness and structure stability of the optimized bridge can meet the relevant specifications,while the cost of construction is greatly reduced,which indicates the optimization effect is significant.
作者
涂兵
刘来辉
邓年春
江建文
李颢旭
TU Bing;LIU Lai-hui;DENG Nian-chun;JIANG Jian-wen;LI Hao-xu(School of Civil Engineering and Architecture,Guangxi University,Nanning Guangxi 530004,China)
出处
《公路交通科技》
CAS
CSCD
北大核心
2021年第12期56-63,72,共9页
Journal of Highway and Transportation Research and Development
基金
国家自然科学基金项目(51738004,51868006)
广西创新驱动发展专项资金项目(桂科AA18118029)
广西高等学校高水平创新团队及卓越学者计划项目(桂教人[2018]35号)
广西自然科学基金项目(2018GXNSFAA138067)。
关键词
桥梁工程
钢管混凝土拱桥
多目标优化
桁式拱肋
截面抗弯刚度
造价
NSGA-Ⅱ遗传算法
bridge engineering
concrete-filled steel tubular(CFST)arch bridge
multi-objective optimization
trussed arch rib
sectional flexural stiffness
cost
NSGA-Ⅱgenetic algorithm
作者简介
涂兵(1988-),男,湖北英山人,博士.(tubing2018@gxu.edu.cn)。
