轻质超高性能混凝土小箱梁优化设计方法  

Optimal Design of Small Box Girder of Lightweight Ultra-high Performance Concrete Beam

作　　者：卢志芳[1] 杜鹏鸣 林驰 LU Zhi-fang;DU Peng-ming;LIN Chi(Hubei Key Laboratory of Roadway Bridge & Structure Engineering,Wuhan University of Technology,Wuhan 430070,China;China Railway Major Bridge Reconnaissance & Design Institute Group Co,Ltd,Wuhan 430050,China)

机构地区：[1]武汉理工大学道路桥梁与结构工程湖北省重点实验室,武汉430070 [2]中铁大桥勘测设计院集团有限公司,武汉430050

出　　处：《建材世界》2022年第2期123-126,共4页The World of Building Materials

基　　金：“十三五”重点研发子课题(2017YFB0310105-03);湖北省技术创新专项(2018AAA-001).

摘　　要：为明确轻质超高性能混凝土(LUHPC)应用于桥梁结构时如何减小截面尺寸,基于数值计算软件MATLAB和40 m跨普通混凝土小箱梁,以相同配筋率下的小箱梁顶板、底板和腹板厚度为设计变量,变形验算、抗裂性验算、上缘压应力验算和斜截面抗剪承载力验算为约束条件,小箱梁自重为目标函数,编写LUHPC小箱梁优化程序,运用fmincon函数优化计算,形成LUHPC小箱梁优化设计方法。并建立LUHPC小箱梁和普通混凝土小箱梁有限元模型,通过对比分析两种小箱梁的弯矩、剪力、应力、挠度等力学性能,并验证优化结果的合理性。得到优化结果:LUHPC小箱梁的顶板、底板和腹板厚度分别减少了40 mm,40 mm和20 mm;LUHPC小箱梁自重比普通混凝土小箱梁减小27.7%。In order to clarify how to reduce the cross-sectional size of lightweight ultra-high performance concrete(LUHPC)when applied to bridge structures,this paper was based on the numerical calculation software MATLAB and 40 m-span ordinary concrete small box girder.Under the same reinforcement ratio,the top,bottom plates and web thickness of the small box girder were design variables;deformation check calculation,crack resistance check calculation,upper edge compression stress check calculation and oblique section shear bearing capacity check calculation were constraints;and the self-weight of the small box girder was the objective function.The LUHPC small box girder optimization program was written and used by the optimization calculation of fmincon function,and forms the optimization design method of LUHPC small box girder.Then a finite element model of LUHPC small box girder and ordinary concrete small box girder was established,and the mechanical properties such as bending moment,shear force,stress and deflection of the two small box girder were compared and analyzed,and the rationality of the optimization results was verified.The optimized results were obtained:the thickness of the top,bottom and web of the LUHPC small box girder was reduced by 40 mm,40 mm and 20 mm;the dead weight of the LUHPC small box girder was reduced by 27.7%compared with the ordinary concrete small box girder.

关 键 词：轻质超高性能混凝土 小箱梁 结构优化设计 MATLAB Midas Civil 

分 类 号：U448.213[建筑科学—桥梁与隧道工程]