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新建铁路厦门至深圳客运专线榕江特大桥为主跨110m+2×220m+110m的下承式等高连续刚性梁柔性拱,大桥全长662m。大桥桥址区纬度较低,濒临南海,受海洋气象调节,季节风影响明显,施工中需要考虑大桥施工阶段的风振响应及抗风措施,以大桥中跨72号支墩为例,针对施工中可能存在的各种情况,采用Ansys数值模拟程序进行精细化建模,风荷载最不利攻角及风向角风区6°和15°,分析了最大悬臂时,悬臂两侧风荷载分别为50%+100%及100%+100%情况下结构在施工中可能遇到的各种情况的风致动力性能,分析表明:最大悬臂无措施状态下,结构最大拉应力约为269MPa,最大压应力约为-208MPa。将中跨悬臂端搭到临时墩上后,结构最大拉应力降为152.2MPa,最大压应力降为-191MPa。基于数值模拟分析建议台风期施工中应尽量避免结构处于最大悬臂状态,以减小台风对结构的不利作用。同时,可采用上部施加预应力索的抗风措施,以确保施工安全。
The newly constructed flexible continuous arch flexible continuous girder of 110m + 2 × 220m + 110m with the main span of 110m + 2 × 220m + 110m from the Xiamen-Shenzhen Special Passenger Line to the special railway line of the Yongjiang River is 662m long. Due to the low latitude of the bridge site and close to the South China Sea, it is obviously influenced by the seasonal wind due to the adjustment of the marine meteorology. In the construction, the wind-induced vibration response and wind-resistance measures of the bridge during construction should be taken into account. In the case of the possible existence of various models, using Ansys numerical simulation program for fine modeling, the most unfavorable wind load angle and wind direction angle of 6 ° and 15 °, analysis of the maximum cantilever, the cantilever on both sides of the wind load were 50 % + 100% and 100% + 100%, the results show that under the condition of maximum cantilever, the maximum tensile stress of the structure is about 269MPa and the maximum compressive stress is about -208MPa. After hitting the cantilever end of the midspan to the temporary pier, the maximum tensile stress of the structure is reduced to 152.2 MPa and the maximum compressive stress is reduced to -191 MPa. Based on the numerical simulation analysis, it is suggested that the typhoon should avoid the maximum cantilever structure during the construction so as to reduce the adverse effect of the typhoon on the structure. At the same time, the upper part of the anti-wind prestressed cable can be used to ensure construction safety.