基于预应力长悬臂板的连拱拱桥拓宽改造与加固研究

摘要

A large number of early constructed multi-span arch bridges need retrofitting now.Based on Sanhua bridge widening and strengthening project,the effective and convenient constructed widening and reinforcement methods are explored.The structural design,stress control,calculation features and establishment of movement joints of bridge deck widening using prestressed long cantilever slab in details are presented.The structural details and the reinforcement requirements of strengthening the main arch ring through enhancing the extrados and side soffit are analyzed.By the comparative analysis before and after reinforcement,the results show that the strengthening methods proposed in the paper can not only improve the load capacity and the structural stiffness but also ameliorate the section stress state.%大量早期修建的多孔拱桥面临加固改造,研究依托三华大桥拓宽加固工程,探讨行之有效和施工方便的拓宽加固方法.本文详细介绍了预应力长悬臂板拓宽桥面的构造设计、应力控制、计算特点和变形缝设置.深入分析采用拱背和边拱腹加强加固主拱圈的构造细节和配筋要求.经加固前后的对比分析表明:文中提出的加固方案不仅提高了桥梁的承载能力和结构刚度,而且改善了截面应力状态.