UHPC简支箱梁桥的剪力滞效应分析  

Analysis on Shear Lag Effect of UHPC Simply Supported Box Girder Bridge

作　　者：李永 LI Yong(School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China)

机构地区：[1]兰州交通大学土木工程学院,甘肃兰州730070

出　　处：《兰州工业学院学报》2022年第3期35-39,共5页Journal of Lanzhou Institute of Technology

摘　　要：为研究箱梁的剪力滞效应,运用能量变分法和有限元法对比分析了48 m UHPC简支箱梁和C60混凝土简支箱梁在不同荷载工况下,跨中截面和沿梁纵向截面的剪力滞系数分布规律和应力差异。结果表明:变分解和有限元解吻合较好,跨中截面和沿梁纵向截面在工况II下剪力滞效应最明显,在顶板和底板与腹板交接处有最大的剪力滞系数,UHPC箱梁最大剪力滞系数是C60混凝土的0.6%,但UHPC箱梁相比于C60混凝土箱梁截面尺寸减小,使其自重比C60混凝土轻32%;箱梁的最大应力均在工况II下跨中截面,UHPC箱梁的应力大于C60混凝土的应力;相比于各自的极限抗压和抗拉强度,两者压应力均有富余,而拉应力UHPC富余3%,C60混凝土富余-82%。Aiming at the shear lag effect of the box girder,the energy variation method and the finite element method are used to carry out the analysis and the comparison between the 48m UHPC simply supported box girder and the C60 concrete simply supported box girder,under different load conditions,and the distribution law of the shear lag coefficient of the section and their stress.The results show that the variational decomposition and the finite element solution are in good agreement.The shear lag effect is the most obvious in the mid-span section and the longitudinal section of the beam under the II condition,and the maximum shear lag is at the junction of the top and bottom plates and the web.The maximum shear lag coefficient UHPC box girder is 0.6%of C60 concrete.There is little difference between the two.However,compared with C60 concrete box girder,the section size of UHPC box girder is reduced,making its dead weight 32%lighter than C60 concrete.The maximum stress of the beam is in the mid-span section under the II condition,and the stress of UHPC box girder is greater than that of C60 concrete.However,compared with their respective ultimate compressive and tensile strengths,both compressive stresses have a surplus,while tensile stress UHPC has a surplus of 3%and C60 concrete has a surplus of-82%.

关 键 词：铁路桥梁 剪力滞效应 能量变分法 UHPC箱梁 有限元法 

分 类 号：U441[建筑科学—桥梁与隧道工程]