大跨宽幅钢箱梁斜拉桥主梁线形控制

摘要

Zhuankou Yangtze Highway Bridge is a cable-stayed bridge of longitudinal half-floating system with 5 spans and double-pylon double-plane. In addition to the beam segments over the pylon pier tops using the bracket installation, the remaining beams are taking cantilever erection. To realize the bridge geometric control target, we used the finite element software to modeling erection process safety and the bridge geometric control measures on asymmetric construction load, the unstressed manufacturing geometric shapes, structural parameter sensitivity, wide box girder hoisting matching. The results indicate that the bridge and girder unstressed manufacturing geometric shapes symmetry and the construction safety can be realized through the control of unstressed length of cables. By the structural parameter sensitivity identify of main beam weight and cable unstressed length, can effectively realize the bridge geometric control target. Using the mask in the web plate, can realize the section line matching.%沌口长江公路大桥为跨径五跨一联双塔双索面纵向半漂浮体系钢箱梁斜拉桥。主梁除塔区及墩顶梁段采用支架安装外，其余梁段均采用悬臂架设。为了实现成桥线形控制目标，采用有限元软件建立分析模型，对该桥不对称施工荷载下线形控制措施及架设过程安全性、主梁无应力制造线形、参数敏感性、宽幅钢箱梁吊装匹配等进行了精确的分析。结果表明，通过无应力索长控制，可以实现成桥及主梁制造无应力线形的对称性，确保施工安全；对主梁自重和斜拉索下料长度等影响线形的主要敏感性因素进行识别，能有效实现成桥线形控制目标；采用在腹板位置设置马板进行调节，能达到断面线形匹配的目的。