摘要
为分析某大跨度钢箱梁斜拉桥钢主梁大量横隔板U肋开口过焊孔处出现的集中开裂原因,文章采用midas FEA土木工程细部分析通用软件建立钢主梁局部梁段有限元板壳模型,取模型车轴载分别在超车道、中行车道和边行车道上进行加载,对横隔板的受力进行计算。结果表明:横隔板U肋开口过焊孔开裂的主要原因是大量重载车在边行车道上行驶,横隔板人孔距离边行车道较近,削弱了横隔板的刚度,导致该细节部位的疲劳应力幅过高,达到结构的疲劳强度,从而产生疲劳开裂;此外,钢箱梁顶板的厚度、U肋开口过焊孔圆弧形切口形式均会对此处的疲劳应力产生较大的影响。研究可为指导钢箱梁横隔板开裂维修、改进钢箱梁横隔板U肋开口过焊孔细部构造设计提供参考。
To analyze the cause of concentrated cracking at the U-shaped rib opening welding hole of numerous transverse diaphragms in the steel main girder of a cable-stayed bridge,this paper used midas FEA,a general civil engineering detail analysis software,to construct a finite element plate-shell model of a local steel main girder segment.The model's axle load was loaded on the overtaking lane,middle lane,and side lane,respectively,and the force on the transverse diaphragm was calculated.The analysis shows that the main reason for the cracking of the U-shaped rib opening welding hole of the transverse diaphragm is the high number of heavy-duty vehicles driving on the side lane.The transverse diaphragm manhole is close to the side lane,which weakens the diaphragm's rigidity.This results in a high fatigue stress amplitude in this detail,reaching the fatigue strength of the structure,resulting in fatigue cracking.At the same time,the thickness of the top plate of the steel box girder and the arc-shaped cutout of the Ushaped rib opening welding hole will have a significant impact on the fatigue stress at this location.This research can provide reference for guiding the repair of cracking in steel box girder transverse diaphragms and improving the detailed structural design of Ushaped rib opening welding holes in steel box girder transverse diaphragms.
出处
《内蒙古公路与运输》
2025年第5期21-25,共5页
Highways & Transportation in Inner Mongolia
关键词
大跨度斜拉桥
钢箱梁
横隔板
裂缝
疲劳应力幅
long span cable-stayed bridge
steel box girder
transverse diaphragm
crack
fatigue stress amplitude
