中卫南站黄河大桥混合梁结合段构造分析

Structural Analysis of Joint Section of Hybrid Girder of Zhongwei South Railway Station Yellow River Bridge

宁夏中卫南站黄河大桥是一座总长100+130+40=270 m的梁拱组合体系V腿刚构桥,主梁、主拱均采用混合结构。主梁17井墩V腿两侧及18#墩中跨侧共设置了三个钢一混凝土结合段,用以协调变形和刚度过渡。受吊杆位置等因素制约,结合段位置剪力、弯矩较大,同时拱肋水平推力使得主梁产生轴向拉力,结合段受力较为不利。为保证钢与混凝土连接可靠、传力平顺,设计了有格室前后承压板式结合部,并结合有限元程序精细化模拟,研究了该类型结合部传力机理。

The Zhongwei South Railway Station Yellow River bridge in Ningxia is a beam-arch combination system with V-leg rigid frame bridge with a total length of 270m(100+130+40=270m),The main girder and main arch are all hybrid structures.Three steel-concrete joint sections have been set up on both sides of the 17#leg of the main girder and the middle side of the 18#piers to coordinate deformation and stiffness transition.Restricted by the suspender position and other factors,the shear force and bending moment of the joint section are larger,besides,the horizontal thrust of the arch rib causes the axial tension of the main beam,so the stress of the joint section is unfavorable.In order to ensure the reliable connection between steel and concrete and smooth force transfer,the front and rear pressure plate type joint part with lattice room is designed,and the force transfer mechanism of this joint is studied by means of finite element program refined simulation.