预应力混凝土斜拉桥箱梁剪力滞规律

为了揭示斜拉桥箱梁应力分布情况,对某单索面预应力混凝土斜拉桥箱梁沿纵桥向剪力滞效应的分布规律进行了研究.结果表明:单索面斜拉桥施工阶段不同的位置应采取不同的剪力滞系数进行平面杆系有限元分析,悬臂端索力作用点处该位置用轴力作用的剪力滞系数反映实际受力;索力之间的梁段在索力作用点处,根据弯矩轴力比确定的剪力滞系数反映实际受力;在索力作用点之间跨中的梁段,用弯矩作用的剪力滞系数反映实际受力,索力作用点与跨中之间的梁段,可采用线性插值求得截面剪力滞系数.

Law of shear lag effect in box girder of prestressed concrete cable-stayed bridge

In order to reveal the stress distribution in box girder of cable-stayed bridge, the distribution law of longitudinal shear lag effect in box girder of a certain prestressed concrete cable-stayed bridge with single cable plane was studied. The results show that different shear lag coefficients should be used for different sites to carry out the finite element analysis for the plane frame system at the construction stage of cable-stayed bridge with single cable plane. At the cable force action point in the cantilever end, the shear lag coefficient with the axial effect is used to reflect the actual force. At the cable force action point between the cable forces, the shear lag coefficient determined with the ratio of bending moment and axial force is used to reflect the actual force. At the girder section in the mid-span between the cable force action points, the shear lag coefficient determined with the bending moment is used to reflect the actual force. At the girder section between the cable force action points and mid-span, the shear lag coefficient can be obtained with the linear interpolation.