摘要
为了研究无背索斜拉桥主梁鱼腹式箱形截面钢—混凝土结合段的受力性能和传力机理,以成都市杉板桥为研究背景,利用有限元分析方法,建立了钢—混凝土结合段精细有限元模型。研究结果表明,钢—混结合面在最不利轴力工况下,结构纵向受力构件均处于受压状态且应力水平较低,钢结构最大mises应力为75.8 MPa。混凝土轴向压应力最大值为-12.7MPa,出现在预应力筋锚固区域,其余大部分均低于-8.1MPa,结构整体处于弹性工作状态;栓钉和PBL连接件抗剪安全系数约分别为3.6和3.5。连接件具有一定的安全储备,满足设计要求;轴向荷载首先通过钢格室承压板的面外承压作用将轴力传递至混凝土,然后通过钢格室中PBL连接件将轴力继续传递至混凝土,随后通过翼缘承压板传递部分轴力,其余轴力通过PBL连接件和翼缘栓钉连接件平稳传递至混凝土。其中,钢格室承压板、翼缘承压板分别传递了71%、8%的轴力,是主要传力构件;PBL连接件与栓钉连接件合计传递21%的轴力。
To study the mechanical behavior and load transfer mechanism of steel-concrete joint(SCJ)offish-belly box-section of cable-stayed bridge without backstays,a fine finite element model of Shanban Bridge in Chengdu is established by using finite element analysis method(FEA).The results show that:under the most disadvantageous working conditions of axial force,the longitudinal stressed structure is in compressive state and the stress level is low,and the maximum Mises stress of the steel structure is 75.8 MPa.The maximum axial compressive stress of concrete is-12.7 MPa,which occurs in the anchorage area of pre-stressed steel bars,and most of the rest are below-8.1 MPa,the structure in whole maintaining at the elastic working conditions.The shear safety coefficients of the stud PBL connectors are respectively 3.6 and 3.5,the shear connectors have a certain safety reserve to meet the design requirements.The axial load is first transmitted to the concrete through the out-of-plane pressure of the bearing plate of the steel grid room,and then the axial force is continuously transmitted to the concrete through the PBL connector in the steel grid room,and then the flange pressure plate transmits partial axial force,the rest of the axial force is smoothly transmitted to the concrete through the PBL connector and the flange bolt connector.Among them,the steel grid pressure plate and flange pressure plate respectively transmit 71%and 8%of the axial force,being the main force transmission members.The PBL connector and the stud connector transmit a total of 21%of the axial force.
作者
曾奎
邱敏捷
罗实
ZENG Kui;QIU Min-jie;LUO Shi(China Railway Eryuan Engineering Group Co.Ltd.,Chengdu 610081,China)
出处
《公路》
北大核心
2020年第11期118-123,共6页
Highway
关键词
无背索斜拉桥
鱼腹式箱形截面
钢—混凝土结合段
受力性能
传力机理
有限元分析
cable-stayed bridge without backstays
fish-belly box-section
steel-concrete composite section
mechanical behavior
force transfer mechanism
finite element analysis
