高程效应下软岩交叉隧道爆破衰减系数影响研究

Study on Elevation Effect on Attenuation Coefficient of Blasting in Soft Rock Crossing Tunnel

采用传统的萨道夫斯基公式计算爆源在既有隧道上方或者下方时产生的误差都较大,所以需要考虑高程差的影响。由于衰减系数K,α只受孔径,孔深,装药结构以及岩体地形地质条件的影响,并不受爆源和既有隧道相对位置影响,可以通过工程现场监测数据在考虑高程差的情况下,拟合爆源在既有隧道上方时衰减系数的值。通过拟合的衰减系数来验证爆源在既有隧道下方时衰减系数的准确性。

The errors resulted from the calculation with traditional Sadowski formula when blasting source is above or below the existing tunnel are large, so the elevation difference should be taken into consideration. Since the attenuation coefficient K,α is affected by diameter and depth of hole, charging structure, and topography and geology conditions of rock mass only, with the relative position of blasting source and existing tunnel excluded, the value of attenuation coefficient in case of blasting source above existing tunnel may be fitted through the data from field monitoring with the elevation difference considered. With this fitting attenuation coefficient, the accuracy of the attenuation coefficient in case of blasting source below existing tunnel may be verified.