高坝泄洪消能诱发场地振动的预测方法

为准确预测高坝泄洪消能诱发的大范围场地振动,通过原型观测和水工模型试验有机结合的方法,分别获取"响应"和"激励",避开准确模拟传播过程的难题,利用"激励-响应"间相关关系进行场地振动的预测。结果表明:泄洪消能诱发的场地振动为低频连续型平稳随机振动,主频在1. 5~3. 5 Hz,与地质条件、泄洪流量、运行方式密切相关;模型试验点脉动压力主频频段滤波、合成后的面脉动压力与场地振动响应呈良好的正相关关系,在各级泄洪流量、不同运行方式下,振动响应预测值与现场振动响应实测值误差均在10%以内,预测精度较高。

Prediction method of ground vibration induced by flood discharge and energy dissipation of high dams

To accurately predict the large-scale ground vibration induced by flood discharge and energy dissipation of high dams, a method combining prototype observation with hydraulic model test is proposed. Excitation and response were obtained separately in the present method, avoiding the difficulty of accurately simulating the propagation process. The correlation between excitation and response is used to predict the ground vibration. The results show that the vibration process is characterized with low-frequency, continuous, stationary and random features. The main frequency of the ground vibration is 1. 5Hz to 3. 5Hz, closely related to the geological conditions, flood discharge and operation modes. There is a positive correlation between the ground vibration response and the surface fluctuating pressure which is obtained by filtering and synthesizing of the point fluctuating pressure in the model test. Under different discharge levels and operation modes, the error between the predicted and the measured response values is within 10%, indicating a high prediction accuracy for the proposed method.