大跨度钢管混凝土拱桥拱肋弹塑性阶段应力分布特点研究  

Research of stress distribution of arch ribs of long-span concrete-filled steel tubular arch bridge with elastoplastic phase

作　　者：何星传 覃霞[1] 韦冬炎 彭林欣[1,2] HE Xingchuan;QIN Xia;WEI Dongyan;PENG Linxin(College of Civil Engineering and Architecture,Key Laboratory of Disaster Prevention and Engineering Safety of Guangxi Province,Guangxi University,Nanning 530004,China;Key Laboratory of Engineering Disaster Prevention and Structural Safety of Ministry of Education,Key Laboratory of Disaster Prevention and Engineering Safety of Guangxi Province,Guangxi University,Nanning 530004,China)

机构地区：[1]广西大学土木建筑工程学院,广西南宁530004 [2]广西大学广西防灾减灾与工程安全重点实验室工程防灾与结构安全教育部重点实验室,广西南宁530004

出　　处：《混凝土》2021年第11期63-69,79,共8页Concrete

基　　金：国家自然科学基金资助项目(11562001,11102044);广西科技重大专项(桂科AA18118029)。

摘　　要：为了研究大跨径钢管混凝土拱桥拱肋弹塑性阶段截面应力分布特点,以平南三桥为工程背景,分别推导了钢管混凝土拱肋在弹性、弹塑性阶段应力分配的理论公式,并与有限元数值仿真试验计算结果进行对比分析。研究表明:在弹性阶段,钢管与混凝土应力是按照弹性模量进行分配,超高性能混凝土(Ultra-high Performance Concrete,UHPC)的弹性模量大于普通混凝土,因此UHPC的压应力约为钢管的25%,而普通混凝土仅约为18%,同时在该阶段混凝土还具有较大的压应力储备;在弹塑性阶段,钢模量减少,混凝土应力持续增大,混凝土的应力增加到钢管的45%,采用UHPC才能满足其强度需求。因此,将钢管与UHPC组合,通过适当减小钢管壁厚让钢适时屈服进入弹塑性阶段,可在一定程度上发挥UHPC的抗压性能,减少结构用钢量。To study the characteristics of stress distribution in the section of arch ribs of long-span concrete-filled steel tubular arch bridge during the elasticity phase,the Third Bridge in Pingnan,Guangxi Province,is taken as the project background.Theoretical formulas about stress distribution in the elastic and the elastoplastic phase of arch ribs of concrete-filled steel tubular were derived separately,which are compared with the solutions given from the finite element model.The results show that steel pipe and concrete stresses are distributed according to the elastic modulus,which is greater in ultra-high performance concrete than in ordinary concrete in the elastic phase.The compressive stress of ultra-high performance concrete is about 25 percent of that in steel pipe,but ordinary concrete only take approximately 18 percent in steel pipe compared to ultra-high performance concrete,and the concrete has a large reserve of compressive stress at that stage.During the elastoplastic phase,the steel modulus decreases while the concrete stress continues to increase and the concrete stress increases to 45%of the steel pipe,so ultra-high performance concrete is necessary for strength requirements.Therefore,the combination of steel pipe and ultra-high performance concrete,Take a reasonable approach to reduce the steel pipe′s thickness in order to make the steel to yield in time and enter into the elastoplastic stage appropriately,the compression resistance character of ultra-high performance concrete could be used in a certain extent and the consumption of steel can be reduced.

关 键 词：钢管混凝土拱肋 UHPC 应力重分布 有限元 弹性 弹塑性 

分 类 号：TU528.01[建筑科学—建筑技术科学]