黑瞎子岛乌苏大桥索梁锚固结构模型静力试验研究

Test Study of Static Force of Cable-to-Girder Anchorage Structure Model of Wusu Bridge in Heixiazi Island

黑瞎子岛乌苏大桥主桥为跨径(140+140)m的独塔单索面大挑臂钢箱结合梁斜拉桥,该桥斜拉索与主梁之间采用钢锚箱式索梁锚固结构。为确保索梁锚固结构在使用阶段的安全性,采用有限元法和足尺模型静力试验相结合法,研究索梁锚固结构在1.0倍最大设计索力作用下的传力路径和应力分布,以及1.7倍最大设计索力作用下的安全性。结果表明:1.0倍最大设计索力作用下,索力经由锚箱承压板、锚箱顶板的焊缝传递至锚箱腹板,再由锚箱腹板与主梁腹板的焊缝传递至主梁,传力路径明确且整体应力水平较低;1.7倍最大设计索力作用下,结构仍处于弹性阶段,受力合理,具有足够的安全储备。

The main bridge of the Wusu Bridge in Heixiazi Island is a long cantilever steel box composite girder cable-stayed bridge with a single pylon, a single cable plane and with span ar- rangement （140＋140） m. The stay cables and main girder of the bridge are connected, using the steel anchor box cable-to-girder anchorage structure. To ensure the safety of the structure at the service stage, the combined method of the finite element analysis and full-scale model static force test was used to study the load paths, stress distribution and safety of the structure respectively under the action of 1.0 time and 1.7 times of the maximum designed stay cable force. The results of the study demonstrate that under the action of the 1.0 time of the maximum designed stay ca- ble force, the stay cable force transfers to the steel anchor box webs via the welding seams of the bearing plate and top plate of the anchor box and then transfers to the main girder via the welding seams of the anchor box webs and main girder webs. The load paths are clear and the integral stress level is low. Under the action of the 1.7 times of the maximum designed cable force, the structure remains elastic, the force conditions of the structure are rational and the structure has sufficient safety margin.