混凝土箱梁桥竖向预应力作用下腹板应力场分析

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

基于有限元分析方法和差分分析方法,对预应力混凝土连续箱型梁桥的腹板竖向预应力作用下的应力场进行了分析,并与现行设计方法进行了比较,指出了腹板开裂的主要原因.分析表明腹板竖向预应力大小不能按现行桥梁设计规范进行设计.为指导砼箱梁桥设计和防治砼箱梁桥开裂,修改有关设计规范提供了理论依据.图12,表2,参5.

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.