大跨度拱桥吊装施工线形控制研究

Analysis and construction control of a large span arch bridge

以某大桥为例,探讨大跨度拱桥吊装施工线形控制方法。根据拱肋预制节段吊装就位过程的特点,提出刚性-弹性索法结合正装迭代法进行吊装过程理论分析,以得到拱肋就位坐标;通过事先在拱肋预制节段中布设坐标观测点对拱肋吊装过程和拱上建筑加载过程中的变形状况进行现场监测。监测结果表明:该大桥各圈拱肋的合拢线形与理论线形吻合良好,其高程误差符合相关规范的要求。通过对该桥施工过程进行严密监控,确保工程质量和施工安全。该桥的成功建成表明上述方法具有较好的适应性,可供类似桥梁参考。

The configuration controlling measures of large span arch bridges were discussed by taking the construction of certain bridge as an example. According to the actual lifting and assembling process of the precast segments of the arch ribs, a theoretical analysis method is called rigid - elastic cable method was proposed for ac- quiring the installing coordinates of precast arch rib segments. Observation points for three dimensional coordinates gauges were installed prior to the lifting and assembling of the precast arch rib segments in order for in situ monitoring of the deformation of the arch during its lifting and assembling process as well as the construction process of the up - arch superstructure. The monitoring results show that the closure curves of all the arch ribs are in a good accordance with the theoretical ones, and the elevation errors of the arch ribs meet the demand specified by the relevant codes, and the deformation induced in the construction of up - arch superstructure develops evenly in the whole arch within safety limits. Through such a severe monitoring of its construction process, the quality and construction safety of the bridge are ensured, and the successive construction of the bridge illus- trates the favorable applicability of the proposed methods, which can be adopted in the construction of similar structures.