水下爆破激励堤岸振动主频的衰减规律

Attenuation Law of Dominant Frequency of Bank Vibration Excited by Underwater Blasting

为了探究水下爆破激励堤岸岩土振动的主频及其传播过程的衰减规律,采用量纲分析法,考虑水、土介质变化物征,建立了影响爆破振动主频各物理量之间的泛函。结合江西省宜春市秀江双桥爆破拆除作业获得的水下爆破振动在堤岸及其近邻域传播测试数据,通过回归拟合,求解爆破振动主频公式。得到爆破振动主频预测值与实测值的平均相对误差为8.87%,较未考虑水土介质变化特征的预测方法得到的平均相对误差小。结果表明,通过引入监测点距爆心之间水、土介质传播域距离比值系数,使得振动主频的预测表达式符合水下爆破振动在堤岸传播的工程物理实际。

In order to explore the main frequency of bank geotechnical vibration excited by underwater blasting and its attenuation law in propagation process,dimensional analysis method was applied to establish the functional between physical parameters that affect the main frequency of blasting vibration,considering the influence of water and geotechnical medium variation.Combined with the experimental data of underwater blasting vibration propagation on bank and its surroundings in the blasting demolition project of Xiujiang Double Bridge in Yichun City,Jiangxi Province,the formula of dominant frequency of blasting vibration was solved through regression fitting.The average relative error between the predicted value and the measured value of blasting vibration dominant frequency is 8.87%,which is smaller than that obtained by the prediction method without considering the variation characteristics of water and soil media.Results show that,by introducing the distance ratio of water and geotechnical medium between monitoring point and blasting center,formula deduced by the dimensional analysis has better accuracy in predicting the dominant frequency of blasting vibration in underwater blasting.