荷载作用位置对曲线钢箱梁桥剪力滞效应的影响

Shear Lag Effect on the Loading Position of Curved Steel Box Girder Bridge

文章通过有限元软件,以苏州中环快速路高新区段的三跨曲线钢箱梁桥为实例进行建模,然后对不同荷载作用位置下曲线钢箱梁桥的剪力滞变化进行分析。结果表明:无论在哪种加载位置下,剪力滞系数的横向分布总是在两翼缘处变化较为平缓,其它部分波动较大,剪力滞系数值在1上下反复浮动,不断在经历着"正剪力滞"和"负剪力滞"现象的切换,数值变化较大且不规律。而直线箱梁剪力滞系数变化十分圆滑,规律且具有对称性。不同荷载位置对大部分截面剪力滞影响较小,而对中间两支座附近截面的剪力滞影响较大。加载的纵向位置距离中间支座附近截面越远,对其剪力滞的影响就越大,且加载的横向位置越靠近内侧,对其剪力滞的影响就越大。

Based on the finite element software, take suzhou high-tech zone of central expressway three-span curved steel box girder bridge as an example of modeling, and then the change of the shear lag of steel box girder bridge under different load position were analyzed.Results show that no matter under what kind of load position,the transverse distribution of shear lag coefficient always changes gently at the wing edge while other parts fluctuate sharply.The value of shear lag coefficient floats up or down at 1.It is constantly going through the switch between positive shear lag and negative shear lag and its value changes greatly and irregularly.However,the shear lag coefficient of straight box girder changes smoothly, boasting regularity and symmetry.Different load position has little influence on shearing force lag of most cross sections but has great effect on shearing force lag of the section near two blocks in the middle.The farther of the distance between the loaded lengthwise position and the section near intermediate support, the bigger the effect on its shearing force lag.In addition, the closer the loaded horizontal position to the inner side, the greater the effect on its shearing force lag.