下承式单拱斜跨空间索面钢箱拱桥施工技术

Construction Technology of Steel Box Arch Bridge with Single Arch under Bearing Diagonal Span Space Cable Plane

下承式单拱斜跨空间索面钢箱拱桥的外形美观、跨越能力强,但其单拱空中旋转的特殊结构,导致施工的难度更大。结合克兰河大桥工程实例,在常规下承式钢箱拱桥施工的基础上,于钢管支架体系中加入斜支撑、立柱等临时支撑结构,在提高支撑效果的同时,也减少了钢材的使用。另外,为保证施工稳定性,工程还通过有限元模型软件Midas/Civil模拟单拱进行内力分析,在主梁1/4 L和主梁3/4 L变形与位移最大的位置设置风缆,增强单拱的稳定性。结果显示,经过采用以上施工,提前20 d完成了施工,且节约大约30 t钢材,钢箱拱合龙施工顺利,单拱线形符合设计,工程施工稳定,有效验证了此种施工技术的经济合理性,具有显著的应用价值。

The steel box arch bridge with single arch under bearing diagonal span space cable plane is beautiful in appearance and strong in span,but the special structure of the single arch rotating in the air makes the construction more difficult.According to Kelan River Bridge project,on the basis of the construction of conventional steel box arch bridge,temporary supporting structures such as inclined supports and columns are added to the steel pipe support system,which can improve the supporting effect and reduce the use of steel.In addition,in order to ensure the stability of the construction,the project also simulated the internal force analysis of the single arch through the finite element model software Midas/Civil,and set the wind cable at the position of the main beam 1/4 L and the main beam 3/4 L with the greatest deformation and displacement,to enhance the stability of the single arch.The results show that after the above construction,the construction period is completed 20 days ahead of schedule,and about 30 t of steel is saved.The steel box arch closing construction is smooth,the single arch line is in line with the design,and the project construction is stable,which effectively verifies the economic rationality of this construction technology and has significant application value.