劲性骨架混合结构外包混凝土应力研究  

Concrete Encasement Stress for Steel-reinforced Composite Structure

作　　者：赵艳 张晓宇 阳珊清 ZHAO Yan;ZHANG Xiao-yu;YANG Shan-qing(Guangxi Communications Design Group Co.,Ltd.,Nanning,Guangxi 530029,China)

机构地区：[1]广西交通设计集团有限公司,广西南宁530029

出　　处：《公路交通科技》2024年第11期159-166,共8页Journal of Highway and Transportation Research and Development

基　　金：广西重点研发计划项目(AB22036007);广西科技重大专项项目(AA23062022);广西交通运输行业重点科技项目清单项目(QD2022-174-036)。

摘　　要：为了弥补现行公路或建筑行业规范对混合结构外包混凝土应力分析的空白,解决桥梁工程实践中劲性骨架混合结构外包混凝土的开裂问题,保证桥梁结构的安全和耐久性,了解劲性骨架混合结构外包混凝土的应力分布规律、外包混凝土最大应力的影响因素是解决问题的关键。研究方法采用经典弹性力学理论,推导出了在内膨胀或内压力作用下圆柱形钢管-劲性骨架混合结构外包混凝土应力分布以及钢混界面应力的解析表达式,并与数值分析对比,误差较小。研究方法还采用有限元建模,分析方柱形钢管-劲性骨架混合结构在内膨胀力作用下的应力分布规律。结果表明:圆柱形钢管-劲性骨架混合结构外包混凝土环向应力最大值出现在钢管外壁处,越往外越小;环向应力随着壁厚和外包混凝土厚度的增加而减小,随外包混凝土弹性模量的增加而增大;相比圆柱,方柱形钢管-劲性骨架混合结构外包混凝土的最大环向应力分布受截面尺寸的影响更为复杂,方柱形混合结构外包混凝土在厚度较小时,环向应力呈现非线性分布,外包混凝土较厚时,分布情况与圆柱形相近。研究成果为设计中有效控制劲性骨架混合结构外包混凝土的应力,避免外包混凝土开裂提供了参考。To make up for the blank of concrete encasement stress analysis for composite structure in the current highway or construction industry specifications,solve the cracking problem of concrete encasement in steel-reinforced concrete composite structure in the bridge engineering,and ensure the bridge structure safety and durability,the key to solve the problems is to understand the concrete encasement stress distribution rule for steel-reinforced concrete composite structure,and the influencing factors of concrete encasement maximum stress.The classical elasticity theory was used to derive the analytical expressions for stress distribution in the encased concrete with cylindrical steel tube-concrete composite structure under internal expansion or internal pressure,as well as the steel-concrete interface stress.The results were compared with the numerical analysis results,showing small errors.The finite element modeling was also used to analyze the stress distribution rule of square column steel tube-concrete composite structure under internal expansion force.The result indicates that the maximum hoop stress on the encased concrete with cylindrical steel tube-concrete composite structure appears at steel tube outer wall,decreasing as it goes outward.The hoop stress decreases with the increase of wall thickness and encased concrete thickness.It increases with the increase of encased concrete elastic modulus.Compared with cylinders,the maximum hoop stress distribution on the encased concrete with square column steel tube-concrete composite structure is more complex due to the influence of cross-sectional dimensions.When the encased concrete is thin,the hoop stress shows the nonlinear distribution.When the encased concrete is thick,the distribution is similar to that with cylindrical shape.The study result provides the reference for effectively controlling the stress on encased concrete with steel-reinforced concrete composite structure in design,avoiding the encased concrete cracking.

关 键 词：桥梁工程 经典弹性力学 有限元法 劲性骨架混合结构 应力 外包混凝土 

分 类 号：U4415[建筑科学—桥梁与隧道工程]