垫塞钢板对扣索力与主拱线形的影响分析

Influence of Inserting Steel Plates on the Cable Force and Alignment of Main Arch

针对采用悬臂拼装斜拉扣挂法施工的拱桥在拱段间过多地垫塞钢板,造成的拱肋线形严重偏离目标线形问题。笔者基于拱段间几何关系,推导了垫塞钢板后拱段坐标修正公式,并利用有限元软件开展了拱段间垫塞钢板对扣索力与主拱线形的影响研究。研究结果表明:拱肋拼装过程中在拱背垫塞钢板,会增大施工过程中的扣索力,索力误差达49.69%,成拱后拱肋线形高于目标线形,最大线形偏差达204.9 mm;在拱腹垫塞钢板会减小施工过程中的扣索力,索力误差达-50.26%,成拱后拱肋线形低于目标线形,最大线形偏差达-201.9 mm,因此在施工中应慎用钢板垫塞拱段。

Aiming at the problem that the arch rib alignment deviates from the target alignment seriously due to too many steel plates inserting into the arch segments during the construction with the cantilever assembly cable-stayed suspension method,the coordinate correction formula of arch segments after inserting steel plates was deduced,according to the geometric relationship between arch segments.The influence of the padded steel plate between arch segments on the cable force and the main arch alignment was also studied by using finite element software.The results of the study show that:in the process of assembling the arch rib,the steel plate padded at the back of the arch will increase the cable force during the construction process,with the cable force error reaching 49.69%;the alignment of the arch rib after the completion of the arch is higher than the target alignment,and the maximum deviation of the alignment will reach 204.9 mm.The steel plate padded at the arch soffit will decrease the cable force in the process of construction,and the cable force error is up to-50.26%;the alignment of the arch rib after the completion of the arch is lower than the target alignment,and the maximum deviation of the alignment will reach-201.9 mm.Therefore,the use of padding steel plates between arch segments should be precautious in the arch segments construction.