宽幅单箱双室混凝土箱梁顶板纵向裂缝成因分析研究

Analysis and study on the causes of Longitudinal cracks in the roof of wide single-box and double-room concrete box girders

摘要:

随着我国交通运输不断发展，对跨江跨海桥梁的通行需求日益增长，双向八车道通行桥梁的建设数量逐步增多，现浇或节段拼装的宽幅单箱双室混凝土箱梁断面在引桥设计使用频率提升。目前发现此类桥梁在运营初期容易萌发顶板纵向裂缝病害，本文围绕此类病害的成因进行研究分析。首先对病害的特征进行归纳分析，而后分别对汽车效应、温度效应、收缩与徐变、预应力效应、建设期施工工艺等因素进行分析。研究结果表明，对于宽度单箱双室混凝土顶板纵向裂缝的成因受综合因素影响，但特征明显在于横向预应力的上浮以及施工存梁工艺不当会造成此类桥梁更容易萌发顶板纵向裂缝。本文研究成果可为同类桥梁设计建设养护提供技术参考。

Abstract:

With the continuous development of China’s transport, with the increasing demand for river-crossing and sea-crossing bridges, the number of two-way eight-lane bridges is increasing gradually, and the frequency of cast-in-place or segmental assembling wide single-box and double-room concrete box girder sections in approach design is increasing. At present, it is found that this kind of bridge is easy to sprout roof Longitudinal crack disease at the beginning of operation. First of all, the characteristics of the disease were analyzed, and then the car effect, temperature effect, shrinkage and creep, pre-stress effect, construction technology during the construction period were analyzed. The results show that the cause of the Longitudinal crack on the wide single-box and double-chamber concrete roof is influenced by comprehensive factors, however, it is obvious that the rise of transverse prestress and the improper construction technology will cause the roof longitudinal cracks of such bridges to germinate more easily. The research results of this paper can provide technical reference for the design, construction and maintenance of similar bridges