预应力对曲线钢-混凝土结合梁桥内力的影响及计算方法

Influence and Calculation of Prestress on Internal Forces of Steel and Concrete Composite Curved Girder Bridge

基于有限元程序Sap2000建模分析了曲线钢-混凝土结合梁预应力作用下混凝土桥面板、箱梁底板的纵向应力和竖向变形,并给出了钢箱上翼缘及腹板竖向变形云图;结合预应力张拉前后中跨跨中截面顶板径向位移对比表和径向位移差值表,说明预应力作用下在最大跨跨中产生了明显的预拱,且外箱拱起量明显大于内箱;桥面板中跨跨中处径向位移的差值沿桥面宽度由内向外呈线性逐渐增大,内箱有向外移动的趋势,而外箱有向内移动的趋势,这些均由整个截面受到预应力产生的向心与向上扭转的转矩所致。

Based on the finite element program sap2000,the simulation analysis of the steel and con-crete composite curved girder bridge under the action of prestress is performed.The longitudinal stress and vertical deformation of concrete slab and box girder floor and the vertical deformation of steel box top flange and web cloud are given.The difference between the displacement of the mid-sec-tion in the middle span before and after the combination of prestress tensioning indicates that the state of pre-arch is obvious under the action of prestress in the biggest span.It is also found that the pre-arch amount outside the box is greater than that inside the box.The radial displacements difference of the mid-section in the middle span increases linearly from inside to outside along the bridge deck width.The inside box has a tendency to move outward and the outside box has a tendency to move in-ward.These are caused by the centripetal and upward torque of the whole cross section under the ac-tion of prestress.