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为缩短拓宽长联桥梁的拼接时间,根据拓宽长联桥梁横桥向变形一联两端大、中间较小的受力特点,提出了“新、旧桥主梁沿纵桥向部分拼接”的方法;通过有限元方法分析了拼接时间与不拼接段长度对横桥向变形的影响;根据现有规范讨论了采用部分拼接法拓宽的长联桥梁的验算方法;进行了不拼接段钢板拼接构造足尺模型试验。研究结果表明:新、旧桥主梁由桥梁中跨向两边通过现浇湿接缝对称拼接、但在一联两端不拼接的部分拼接法可明显减小新、旧桥支座横桥向变形,从而缩短长联桥梁拼接时间;对于部分拼接法的不拼接段,其纵桥向长度确定原则为,考虑混凝土收缩徐变等长期荷载作用下,根据新桥建成后的静置时间,保证拼接10年后新、旧桥支座最大横桥向位移小于容许值;新、旧桥主梁除了应进行抗弯和抗剪承载力验算外还须进行抗扭承载力验算;当试验荷载加载至相当于2倍公路-Ⅰ级设计荷载过程中,拼接钢板与翼缘连接处以及桥面铺装均未出现开裂或压碎现象,桥面铺装与主梁翼缘的结合面未张开,表明不拼接段新、旧桥主梁翼缘间沿纵桥向等间距设置钢板连接构造进行拼接的方法可避免不拼接段桥面铺装出现裂缝,且保证新、旧桥主梁横桥向不发生碰梁。
In order to shorten and broaden the splicing time of Changlian bridge, according to the characteristics of widening the middle and the middle of the transverse deformation of the Changqiao bridge, The method of finite element method was used to analyze the influence of the splicing time and the length of non-splicing section on the transverse bridge deformation. According to the existing specifications, the checking method of the long bridge with partial splicing method was discussed. Splicing construction full-scale model test. The results show that the main beams of the new bridge and the old bridge are symmetrically spliced by the wet-in-place joints on both sides of the bridge. However, the partial splicing method without splicing at one end and the other end of the bridge can obviously reduce the transverse bridge For the non-splicing section of partial splicing method, the principle of longitudinal span length is determined according to the standing time after the completion of Xinqiao, considering the long-term load such as shrinkage and creep of concrete, etc. After 10 years of splicing, the maximum lateral bridge displacement of new and old bridge supports shall be less than the allowable value; the new and old bridge main girders shall carry out anti-torsional bearing checking in addition to checking bending and shear bearing capacity; To the equivalent of 2 times the highway-Ⅰ design load process, splice plate and flange joints and deck pavement did not appear cracking or crushing phenomenon, the bridge deck and the main beam flange is not open, indicating Splicing section of the new and old bridge between the main flange along the longitudinal direction of the bridge to provide steel plate connection structure splicing method to avoid the splice section of the bridge deck cracks, and to ensure that the new bridge, Beam.