基于有限元仿真大跨PC箱梁底板崩裂机理的研究

   进,王 

(中交第二公路工程局有限公司,陕西 西安710065

  要:某大跨PC箱梁合拢段底板钢束张拉完后,出现了底板局部崩裂破坏现象。为了分析底板崩裂原因,以制定处治方案提供理论支持和参考,本文用平面杆系理论为基础,建立MIDAS模型进行总体分析计算,对合拢段局部区域进行了ANSYS空间仿真,最后采用经典力学进行了对比分析。结果表明,设计底板纵向压应力太强,从而造成预应力径向力过大是导致该桥底板合拢段崩裂的主要原因。

关键词:PC箱梁;底板开裂;径向力;ANSYSMIDAS

中图分类号:U441        文献标识码:A

 

Study on Cracking Mechanism of Long Span PC Box Girder By Finite Element Simulation

LI Jin, WANG Biao

CCCC Second Highway Engineering Co., LTD. Xi’an 710065, China

Abstract:After the steel beam of the bottom plate of a large span PC box girder has been stretched, the phenomenon of partial cracking of the bottom plate appeared. In order to analyze the causes of bursting crack, provide theoretical support and reference to formulate treatment plan, plane frame theory was used in this paper to build the MIDAS model to calculate the overall analysis. And the local area closure section was also been analyzed by ANSYS simulation, the classical mechanics analysis results were compared.The results showed that the longitudinal compressive stress of the design plate is too strong, which results in the excessive radial force of the prestressing force. It is the main cause of the cracking at the bottom of the bridge

key words: PC box girder; Bottom cracking; Radial force; ANSYSMIDAS