Analysis on the stress field in webs of concrete box girder bridge under the action of vertical prestress

According to the analysis methods of finite element and difference,the field of stress in the web of prestressed concrete continuous box girder bridge under the action of vertical prestress was analyzed.Comparing it with the current design ones,this method told the main cracking reason in the web.The analysis result indicates that the value of the vertical prestress should not be calculated by the current design codes of bridge.Besides,it provides the theoretical basis to the modifying of relevant codes,which has the important engineering meaning for the prevention of the cracking in concrete box girder bridges.12figs.,2tabs.,5refs.