露天爆破对既有结构关键振动特征的影响分析

Influence of Open Blasting on Key Vibration Characteristics of Existing Structures

为研究露天爆破对既有结构关键振动特征(振动速度和主振频率)的影响,采用爆破地震波测试仪对爆破区周围结构的振动特征进行测试,分析了露天爆破对既有结构径向、切向、竖向振动速度和主振频率的影响规律。为合理预测和有效控制爆破振动,基于规范法中的修正萨道夫斯基经验公式,采用最小二乘法对爆破振动测试结果进行拟合分析。结果表明:①测点在3个方向上的振动速度随爆心距的增大而减小,其中径向振动速度衰减特征较为显著,且多在0.02~0.70 cm/s;②测点的主振频率随爆心距变化规律不明显,且主振频率分布规律较为随机,多集中在20~50 Hz;③拟合得到了3个方向上振动速度的经验公式,可较好地描述振动速度的衰减规律,进行振动速度的有效预测。研究结果可为类似露天爆破工程提供理论依据及参考,具有工程应用价值。

In order to study the influence of open-pit blasting on the key vibration characteristics(vibration velocity and main vibration frequency)of existing structures,the influence of open-pit blasting on the key vibration characteristics of existing structures was studied,the vibration characteristics of the structure around the blasting area were measured by blasting seismic wave test.The influence of blasting vibration on the vibration velocity and main vibration frequency of the existing structure in radial X,tangential Y and vertical Z was analyzed.In order to reasonably predict and effectively control blasting vibration,the least square method was used to fit the modified Sadovsky empirical formula in standard.The results show that:1)the vibration velocity of the measuring point in X,Y,Z directions decreases with the increase of the explosion center moment,and the vibration velocity attenuation characteristics of radial X were more obvious,and most of them were in 0.02~0.70 cm/s;2)the variation law of the main vibration frequency with the blast centre moment is not obvious,and the main vibration frequency distribution law is more random,mostly concentrated in 20~50 Hz;3)the empirical formula of vibration velocity in X,Y and Z directions is obtained by fitting,which can better describe the attenuation law of vibration velocity and make effective prediction.The research results can provide theoretical basis and reference for similar open-pit blasting engineering,and have engineering application value.