For the problem of a wide range of ground vibration induced by the flood discharge in a hydropower station,the vibration characteristics and influence factors are analyzed based on systematical field monitoring.The results indicate that:(a) the ground and structure vibrations have distinctive characteristics of constancy,low-frequency,small amplitude and impact with a long propagation distance and wide influenced area,and the main frequency of vibration is around 1.5-3 Hz,which is obviously different from usual high-frequency vibration;and (b) the urban environmental vibration has special distribution characteristics and changing rules,and greatly affected by discharge flow,scheduling mode and geological conditions.With the increase of the height of residential buildings,the vibration has a significant amplification effect,and the horizontal and the vertical vibrations are obvious different.The top floor vibration of the buildings based on soft foundation is the most.It is very difficult to reduce large-scale lowfrequency environment vibration,but it is one of effective measures to reduce the excitation from power station scheduling optimization.The vibration reduction measures and anti-vibration safety evaluation still need to be further studied.%针对近期出现的高坝泄洪诱发场地大范围振动问题,通过系统的现场观测,研究了泄洪诱发的环境振动特性.观测表明,泄洪引起的场地、结构振动具有持续、低频、微幅、冲击等鲜明特征,振动主频1.5 ～3 Hz,传播距离远、影响范围大,与常见的高频环境振动明显不同;城区环境振动具有明显的分布特征和变化规律,受泄量、调度方式、地质条件等影响较大,居民楼随高度增加振动有明显的放大效应,水平向与竖直向差异明显,软基上的居民楼顶楼振动最大应当重视.大范围低频环境振动的减振难度很大,从源头优化调度减小激励是当前有效措施之一,减振措施与抗振安全评价仍需进一步研究.
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