丘陵地区混凝土无铰拱桥基础抗震优化设计研究

Study on Seismic Optimization Design of Concrete Hingless Arch Bridge Foundation in Hilly Area

对于丘陵地区采用不同基础形式的混凝土无铰拱桥,地震作用下拱脚间的相对位移较相同基础形式下更大,受力状态更差,群桩基础一侧的拱脚位移主要受群桩布置形式和台后填土控制,确定合理的桩基布置形式、计算模型和边界条件是此类拱桥抗震设计的关键。根据实际工程实例,采用Midas civil建立梁单元和实体单元的三维模型,对地震作用下不同基础形式和不同填土约束和脱空高度下的桩顶和拱脚变形进行对比统计,得出一些相关有益结论,在此基础上提出丘陵地区混凝土无铰拱桥的基础优化设计建议和措施。

For the different foundations of concrete hingless arch bridge used in the hilly area,the relative displacement between the arch foots is larger than that of the same foundation and the stress state is worse under earthquake.The arch foot displacement at one side of group pile foundation is mainly controlled by the layout type of group pile and the back filling.It is a key to determine the reasonable layout type of pile foundation,the calculation model and the boundary conditions for the seismic design of this kind of arch bridge.According to the practical engineering examples,Midas civil is used to establish a 3D model of girder element and solid element for comparing and counting the deformations of pile top and arch foot with the different foundation types and the different filling constraints under the cavity height and earthquake.Some relative beneficial conclusions are obtained.On this basis,the suggestions and measures for foundation optimization design of concrete hingless arch bridge in hilly area are put forward.