【摘要】 为了分析近距离爆破对相邻既有隧道的振动影响,进行了现场爆破振动监测试验。结果表明,振动速度具有很强的方向性,各测点沿隧道断面的径向振动速度均大于切向速度,且振动速度均随着与震源距离的增大呈非线性减小。基于试验结果的统计回归和对爆破中区爆生气体压应力场作用下岩石微裂纹扩展机理的分析,假定岩石动态极限抗拉强度超过微裂纹临界应力时引起新的材料损伤,通过爆破中区损伤断裂准则得到了质点振动速度的安全阈值。结合爆破监测回归公式给出了不同距离情况下单段最大药量建议值。更多还原

【Abstract】 For analyzing the vibration effect on existing tunnel induced by closed-in blasting,the site blasting experiments were monitored.The results show that the vibration velocity is stronly directional,and the radial velocity was larger than the tangential velocity along the tunnel section and the velocity was nonlinear decreased following the distance.Based on the statistical regression of experimental results and analysis of microcrack propagation mechanism of rock under compressive stress field of detonation gas,and on assuming the new damage will be generated when the dynamic failure tensile strength of rock was over the microcrack critical stress,the safety threshold value of particle vibration velocity could be obtained by mid-area damage fracture criterion of blasting.The max charge per delay at different distance was suggested combining with the regression equation of monitor results.更多还原