摘要
以某特大跨径钢管混凝土拱桥为研究对象,进行1∶2.5缩尺的拱肋拱脚段上弦管钢管混凝土构件徐变模型试验,并引入考虑钢管约束的新的钢管混凝土徐变系数,结合有限元模拟和实桥实测,研究特大跨钢管混凝土拱桥的徐变效应。结果表明:试验模型在180 t荷载持续加载1 a后,钢管承担的荷载增加了1.2倍,管内混凝土承担的荷载下降了53%,内力重分布现象明显;截面含钢率和钢与混凝土的弹性模量比对钢管混凝土徐变系数有较大的影响;钢管应力的有限元计算结果与实桥实测结果的变化趋势总体一致,数值接近,且随施工的推进而增大;管内混凝土的应力较复杂,有限元计算结果与实桥实测结果有一定的差别,实桥实测应力较小,甚至出现拉应力。
Taking a super long-span concrete-filled steel tubular(CFST)arch bridge as the research object,the 1:2.5 scaled creep model tests for CFST members on the upper chords of the arch rib and arch foot sections were carried out,and a new CFST creep coefficient considering steel tube constraints was introduced.Combined with the finite element method(FEM)simulation and real bridge measurement,the creep effect of super long-span CFST arch bridge was studied.The results of creep model tests show that the load borne by the steel tube increases by 1.2 times and the load borne by the concrete in the tube decreases by 53%after one year of 180 t constant loading,and the redistribution of internal force is obvious.The sectional steel ratio and steelconcrete elastic modulus ratio have great influence on the creep coefficient of CFST.The FEM calculation results of the steel tube stress are generally consistent with the measured results of the real bridge.Both values are close and increase gradually with the progress of construction.But the stress of the concrete in steel tube is complex,and the FEM calculation results are different from the measured results of the real bridge to some extent.The measured stress of the real bridge is small,and even tensile stress occurs.
作者
曾勇
李勇岐
孙旭东
李学钦
薛晓芳
顾安邦
谭红梅
ZENG Yong;LI Yongqi;SUN Xudong;LI Xueqin;XUE Xiaofang;GU Anbang;TAN Hongmei(State Key Laboratory of Mountain Bridge and Tunnel Engineering,Chongqing Jiaotong University,Chongqing 400074,China;Mountain Bridge and Materials Engineering Research Center of Ministry of Education,Chongqing Jiaotong University,Chongqing 400074,China)
出处
《中国铁道科学》
EI
CAS
CSCD
北大核心
2021年第5期76-84,共9页
China Railway Science
基金
国家自然科学基金资助项目(51908093)
国家留学基金资助项目(201308505149)
重庆市留学人员回国创业创新支持基金项目(CX2018113,CX2020117)
山区桥梁及隧道工程国家重点实验室开放基金项目(CQSLBF-Y16-10)。
关键词
拱桥
钢管混凝土
徐变效应
应力重分布
模型试验
有限元分析
现场实测
Arch bridge
Concrete-filled steel tubular
Creep effect
Stress redistribution
Model test
Finite element analysis
In-situ measurement
