【摘要】 强烈地震作用下,水与群桩基础的互相作用问题一直没有得到很好解决。本文使用结构自由振动衰减力锤激励的方法对深水桥梁群桩基础考虑水影响下的动力特性进行了有益的探索与研究。以某深水桥梁群桩基础为工程背景,设计制作试验水池及缩尺比为1/30的九桩模型,介绍了在不同水深环境下进行模态试验的方法;同时利用有限元分析软件ADINA建立了水-结构相互耦合作用的三维实体有限元模型,对其动力特性进行了理论分析。通过比较不同水深环境下结构振动一阶侧弯与扭转阵型的试验与理论分析结果,验证了本文针对群桩基础结构模型所用的自由振动衰减模态试验方法是成功的;在考虑水-结构相互耦合作用后,结构的振型周期延长,频率减小;随着水深增加,结构频率变化越大。更多还原

【Abstract】 The problem of water-structure interaction under strong earthquake is not well solved.Considering the water influence,the dynamic characteristics of deep-water bridge group foundation were experimentally studied by using the structural free vibration attenuation hammer excitation method.Taking a deep-water group pile foundation of bridge as an example,a test pool and a nine-pile model with the scale ratio of 1/30 were designed,and its method of modal test under different water depths was introduced.At the same time,the three-dimensional solid finite element model with water-structure interaction was built in finite element analysis program ADINA,and its dynamic characteristics were analyzed theoretically.Comparing the experimental and theoretical analysis results of the first lateral vibration and torsional modes under different water depths,it proves that the free vibration attenuation method of modal test for the group pile foundation model is feasible.The water-structure interaction results in the structural frequency to decrease and the structural frequency changes more significantly with the increase of the water depth.更多还原