上海市轨道交通17号线在国内首次采用了预应力混凝土U型+箱型复合截面连续梁桥,该桥设计中针对常规U型截面梁适用跨径有限,难以用于大跨连续梁桥的难题,提出了箱型截面与U型截面上下组合形成的复合截面,通过有限元方法分析研究了该型截面的力学特性,明确了其设计方法及控制指标,并应用于主跨跨径70米的连续U梁桥。该桥采用预制节段悬臂拼装,施工周期短,对周边环境影响小,施工质量优良,经济效益显著。施工期间的应力跟踪监测以及成桥后的静载试验结果验证了该型连续U梁桥的设计合理、施工可靠和结构安全。

A prestressed concrete continuous beam bridge with composite section which combining U-shape section with box section is first constructed in No.17 rail transit line in Shanghai. In order to increase the applicable span of through girder with U-shape section to meet the requirements of large span bridges, a continuous through girder with brand-new section which is composed of upper U-shape section and lower box section is introduced. The mechanical properties of the girder is analysed by finite element method and its design procedure and standards are determined subsequently. The main span of the continuous through girder bridge with the composite section is 70 meters. This newly-built bridge is segmental concrete bridge constructed by free cantilever technique and incremental launching of precast segments which shortens the construction period, reduces the impact on environment, guarantees the quality of segments and make distinguished financial gains. Monitoring the stress changes in construction period and the dead load test on completed segmental bridge has been done effectively and through which the excellence of design and construction of the bridge as well as its safety is verified.

U442.5