拼接时间对拓宽装配式预应力混凝土连续箱梁桥的影响

Influence of Stitching Time on Widening Prefabricated Prestressed Concrete Continuous Box Girder Bridge

针对高速公路扩建工程中急需解决的预应力混凝土连续箱梁拓宽技术及新旧箱梁之间相互影响的问题,结合某高速公路扩建中的预应力混凝土连续箱梁桥实例,采用有限元分析法对新旧桥梁拼接时间的选择以及拼接后主梁应力的变化情况进行分析。分析表明:新桥在成桥6个月内由收缩徐变引起的主梁应力较大,6个月后收缩徐变引起的主梁应力逐渐减小,新旧桥梁拼接时间选择在新桥成桥6个月后比较合适。

In view of the problem that the widening technology of prestressed concrete continuous box girder and the interaction between new and old box girders are urgently needed to be solved in the expressway extension project, combined with a prestressed concrete continuous box girder in the extension of a certain expressway, the selection of stitching time of new and old bridges and the change of stress of the post-stitching girder are analyzed and studied by the finite element analysis method. The analysis shows that the main beam stress caused by shrinkage and creep is bigger within 6 months of the new finished bridge, and it gradually reduces after 6 months, and the stitching time of new and old bridges is more suitable 6 months later after the new bridge is completed.