传播介质特性对爆破振动衰减规律的影响

以《工程岩体分级标准》为依据,量化作为爆破地震波载体的传播介质的特性,并采用离散单元法分析爆破地震波在传播介质中的衰减过程。数值模拟过程中详细阐述了爆破荷载、介质阻尼及相关参数的确定方法,分析了传播介质特性对爆破振动速度衰减规律及萨道夫斯公式中K、α值的影响。研究表明,在爆破荷载作用下,近距范围内爆破振动速度迅速衰减,中远距范围内爆破振动速度衰减趋缓;传播介质为Ⅰ~Ⅲ级岩体时,随着岩体质量降低,K值有增大趋势,对于Ⅳ~Ⅴ级岩体,K值变化没有明确的规律;α值总体上具有随岩体质量降低而增大的趋势,K、α值具有与爆破振动速度近似相同的增减关系。

The Influence of the Characteristic of Medium on the Attenuation Law of Propagation of Vibration Due to Blasting

Based on the criterion of the classification of rock mass,the characteristic of the medium which behaves as the carrier of the seismic wave due to blasting is quantified.Distinct Element Method(DEM) is used to analyze the process of the attenuation of the seismic wave due to blasting in the medium.The determination of the blasting loading,damping and relevant parameters is detailed in the numerical modeling.The influence of the characteristic of the medium on the attenuation law of the velocity of the vibration due to blasting and on the value of K、α in the empirical formula are studied.It reveals that the velocity of the vibration due to blasting decreases rapidly in the near field and slowly in the far field.When the medium is classified as Ⅰ～Ⅲ,K increases with the decrease of the quality of rock mass.For medium classified as Ⅳ～Ⅴ,there is no definite rule for K to follow.Generally speaking,α increases with the decrease of the quality of rock mass.The variation K and α is approximately the same as that of the velocity of the vibration due to blasting.