波浪作用下局部冲刷群桩动力特性试验研究

摘要

Using swing wave-making device to exert wave loading,a model test is conducted to study the deep-water group piles.Simulating different scour depths by excavating the pile-surrounding soil,we probe into the dynamic response of the pile foundation at different depths under the wave action.Parallel contrast tests of single pile foundation at the same parameters are also conducted for a comparison.The results show that the natural frequency of deep-water structure is changing during the vibration.As the scour depth increases,the natural frequency of pile decreases,and the acceleration and displacement of the pile top also increase.At the same time,these responses increase with the increasing depth of water.In design,both piles' scouring damage degree and hydrological condition should be considered.%利用模型试验对深水桥墩群桩基础进行研究.用摇摆式造波装置施加波浪荷载,基于典型的冲刷坑形态,通过开挖桩周土体模拟不同的冲刷深度,探讨不同冲刷深度下桩基在波浪荷载作用下的动力反应.作为对比,同样进行了同参数下的单桩平行试验.研究结果表明:随着冲刷深度的增加,桩基础的自振频率逐渐降低,桩顶加速度和位移幅值呈增大趋势.桩基动力响应同时受水深的影响——随着水深的增大,位移和加速度也有所增加.在实际工程设计中,应该考虑桩基冲刷受损程度和水文条件的综合影响.