斜拉桥主塔施工过程风致抖振时域分析及安全性评定

对杭州湾大桥南通航孔斜拉桥进行桥塔施工架设期间的抗风分析。根据桥塔施工进度确立中塔柱合拢前及桥塔自立状态为抗风控制状态,针对2种施工控制状态建立有限元模型,分别进行了抖振时域分析及施工阶段全过程静力分析,并对桥塔在施工过程中结构和施工人员安全进行了评价。结果表明:施工阶段设计风荷载作用下,2种抗风控制状态桥塔控制截面拉应力都不大,结构不会出现损伤;但塔柱顶部抖振振幅及狄克曼指标都较大。

Time-Domain Analysis and Safety Evaluation of Wind-Induced Buffeting on Pylon of Cable-Stayed Bridge at Construction Stage

The wind resistance analysis is made for pylon of the south navigable cable-stayed bridge of Hangzhou Bay Bridge at construction stage.In accordance with the construction progress of the pylon,the states of the mid-pylon shafts before they are closed and free standing of the pylon are determined as the control states of wind resistance of the pylon.The finite element models for the pylon are then established for the two kinds of the control states,the time-domain analysis of wind-induced buffeting and static analysis of the whole construction process of the pylon are respectively carried out,and the structural safety and construction crew safety at the construction stage of the pylon are evaluated.The results show that the tensile stress of the control cross sections of the pylon of the two kinds of the control states is not great under design wind load at the construction stage and the structure will not be damaged,however,the amplitude of buffeting at the tops of the pylon shafts and the Diekemann index are fairly great.