900 t运梁车过钢桁斜拉桥方案研究

Scheme Research on 900 t Girder Transporting Vehicle Passing through Steel Truss Girder Cable-stayed Bridge

徐盐铁路盐城特大桥主桥采用(72+96+312+96+72)m连续钢桁斜拉桥,按不通行运梁车设计,主桥大里程侧少量简支箱梁采用移动模架法施工。受盐城站南移影响,主桥大里程侧的简支箱梁增至170余孔,新增梁场将增加征地及投资,且不满足总体工期需求,故主桥大里程侧的简支箱梁拟采用预制架设法施工。钢桁斜拉桥需研究900t运梁车通过方案,针对900t运梁车过桥各种不利工况,建立了相应的整体和局部有限元计算模型进行分析。分析结果表明,采用在正交异性钢桥面板上铺设临时钢筋混凝土板的方案较为经济合理,能够满足斜拉桥结构受力要求,可为今后类似铁路工程建设的设计和施工组织提供参考。

The main bridge of Yancheng Grand Bridge on Xuzhou-Yancheng Railway adopts (72 +96 +312 +96 + 72) m continuous steel truss cable-stayed bridge. The original design had not considering the girder transporting vehicle loads, and a small amount of simply supported box girders on the large mileage side of the main bridge was designed to be constructed by moving module method. Affected by the southbound geographical movement of Yancheng Railway Station, the total amount of simply supported girders on the large mileage side increases to more than 170. Hence, new beam fabrication yards are necessary for the purpose of meeting the tight construction schedule, which leads to extra land acquisition and in creasing investment. Therefore, the precast erection method is adopted for the box girders. It is necessary to study the passing scheme of 900 t girder transporting vehicle through the steel truss cable-stayed bridge. Global and partial finite element models are established with the consideration of various unfavorable working conditions, specifically for 900 t girder transporting vehicle passing the main bridge. The results show that laying temporary reinforced concrete slab on orthotropic steel bridge deck is the reasonable scheme which not only satisfies the structural requirements of the cable-stayed bridge but also is economical and rational. The study could be referred to the design and construction organization of similar railway projects.