大跨度连续刚构桥波形钢腹板内衬混凝土承剪比研究

大跨度桥梁结构设计时墩顶附近钢腹板承受的剪力一般较大。在梁高较大的情况下,波形钢腹板易受几何形状不规则的影响,导致剪力屈曲强度下降。为了防止波形钢腹板发生屈曲破坏,通常采用在墩顶附近增设内衬混凝土来提高波形钢腹板的抗屈曲承载能力。本文以徐水沟特大桥为工程背景,采用规范简化计算公式并建立不同厚度内衬混凝土的有限元数值仿真模型,对波形钢腹板内衬混凝土厚度、承剪比及竖向荷载作用下的钢腹板和内衬混凝土应力状态进行研究。结果表明:当内衬混凝土的厚度在20～60 cm时,其承剪效果较好;竖向荷载对波形钢腹板和内衬混凝土的承剪比无影响。

Study on Shear Ratio of Concrete Lining with Corrugated Steel Webs in Large Span Continuous Rigid Frame Bridge

In the design of large span bridge structure,the shear force of the steel web near the top of the pier is generally large.When the beam height is large,the corrugated steel web is easily affected by the irregular geometry,which leads to the decrease of shear buckling strength.In order to prevent buckling failure of corrugated steel webs,the buckling bearing capacity of corrugated steel webs is usually improved by adding concrete lining near the top of the pier.Taking Xushuigou bridge as the engineering background,the stress states of steel web and concrete lining under the thickness of concrete lining, shear ratio and the action of vertical load were studied by using simplified calculation formula and establishing finite element numerical simulation model of concrete lining with different thickness.The results show that when the thickness of concrete lining is in the range of 20~60 cm,the shear effect of concrete lining is better,and the vertical load has no effect on the shear ratio of corrugated steel web plate and concrete lining.