摘要
转向块是波形钢腹板组合梁桥最重要的传力构件之一,其受力复杂,易成为结构设计的薄弱点。采用空间有限元实体模拟的方法,对转向块在实际工作中的应力分布特点和规律进行研究。结果表明,竖向拉应力由底板连接处向中部逐渐减小,是设计的控制因素;当预应力管道距离底板较近时,管道下缘的应力不能充分扩散,会产生明显的应力集中,对设计很不利;转向块与顶底板连接处的倒角对应力扩散效果显著;主拉应力具有使转向块从梁体内脱离的倾向,两者之间应加强钢筋连接;转向块可采用上薄下厚、半高度等构造形式及钢结构材料等方式来实现轻型化设计。
Deviation block is one of the most important force transfer members of composite girder bridges with corrugated steel webs.Its load is complicated and it is easy to become the weak point of structural design.The stress distribution characteristics and law of deviation block in practice operation are studied by spatial finite element simulation method.The analysis result show that the vertical tensile stress decreases gradually from the bottom plate to the middle,which is the controlling factor of the design.When the prestressed pipe is close to the bottom plate,the stress at the lower edge of the pipe cannot be diffused sufficiently,which will produce obvious stress concentration,which is very bad for the design.The chamfering of the joint between the deviation block and the top and bottom plate has a significant effect on stress diffusion.The main tensile stress has the tendency to make the deviation block detach from the beam body,and the reinforcement connection between them should be strengthened.The structural form of deviation block can be thin in the upper and thick in the lower with half height and steel structure materials to achieve lightweight design.
作者
周晓夫
ZHOU Xiaofu(Sichuan Communication Surveying&Design Institute Co.,Ltd.,Chengdu 610000)
出处
《公路交通技术》
2021年第3期57-63,共7页
Technology of Highway and Transport
关键词
体外预应力
转向块
应力分布
应力集中
external prestress
deviation block
stress distribution
stress concentration
