关键词: 桥梁工程, 腹板开裂, 混凝土收缩徐变, 泊松效应, 有限元分析

Abstract: In the practical engineering, box girder web cracking phenomenon is common, and causes of cracking in webs are complex and diverse. The main causes of web cracking of box girder were discussed from the perspective of qualitative and quantitative analysis. It is concluded that: ①the specific causes of web cracking of box girder mainly include concrete shrinkage, temperature effect, radial force caused by bending of prestressing tendons and Poisson effect caused by compressive stress in anchorage zone; among them, the radial force caused by bending of prestressing tendons and Poisson effect caused by compressive stress in anchorage zone are the main causes of box girder web cracking; ②the web cracks caused by these two factors are analyzed by the finite element software ANSYS through engineering examples, and the results show that the web cracking of box girder is easy to occur in the bending section of web prestressing tendons, and its direction is basically perpendicular to the bending prestressing tendons.

Key words: bridge engineering, web cracking, shrinkage and creep of concrete;Poisson effect, finite element analysis