沧河南大桥加宽改造动力优化设计

Dynamic Optimization Design for Widening of the South of Canghe River Bridge

以京港澳高速公路安阳—新乡段沧河南桥为工程背景,采用有限元程序MIDAS建立该桥的空间有限元计算模型,对采用刚度渐变的空心桥进行动力响应分析。计算结果表明:施加横向刚度渐变构件前,作用有移动荷载的桥板跨中动力位移与相邻桥板相比,出现明显的位移突变,属于典型的单板受力;施加横向刚度渐变构件后,作用有移动荷载的桥板跨中位移明显减小,且与之相邻桥板的跨中动力位移较为相似。另外,施加横向刚度渐变构件前,各板振动存在不同步现象;施加横向刚度渐变构件后,各桥板之间振动协调性大大增强。从动力效果分析,也说明了施加横向刚度渐变构件的必要性和有效性。

The south of Canghe River Bridge of the Beijing-Hong Kong-Macao highway from Anyang to Xinxiang is taken as the engineering background. Its spatial finite element model is established by finite element program MIDAS. The dynamic response analysis of hollow slab bridge applying rigidity gradient model is carried out. The calculation results show that： before using lateral rigidity gradient components, the span dynamic displacement of the bridge slab that enduring moving load presented displacement saltation, comparing with adjacent slabs; while after using that, and similar with that of the adjacent slabs. In addition, before using lateral rigidity gradient components, there was asynchronous vibration phenomenon in each plate; after using that, the coordination of vibration displacement during slabs enhanced greatly. The dynamic response analysis also proved the effectiveness and necessity for using lateral rigidity gradient components.