危岩体爆破参数敏感度分析及爆破振动安全判据

Sensitivity analysis on blasting parameters of dumping dangerous rock mass and blasting vibration safety criterion

在爆破开挖施工过程中,产生的爆破地震波会对周边危岩体稳定产生不利影响。为分析爆破参数对倾倒式危岩体稳定性的影响,以白岩山隧道工程为例建立了工程地质模型并进行分析计算,提出了时程分析法的危岩体爆破振动安全判据及基于一维应力波理论的危岩体爆破振动判据的计算方法。分析结果表明:危岩体的动力稳定性安全系数受爆破最大单响药量和爆心距的影响,当危岩体尺寸超过了爆破地震波的波长时,则要考虑爆破振动频率衰减效应和相位差;经过对两种判据方法分析比较,建议白岩山隧道危岩区最大允许振速按照[V]=0.57cm/s进行控制。研究成果对类似工程优化爆破和危岩区防震减灾具有重要参考价值。

In the blasting excavation process,the blasting seismic wave will adversely affect the stability of the surrounding dangerous rock mass.In order to analyze the influence of blasting parameters on the stability of dumping dangerous rock mass,an engineering geological model was established based on Baiyanshan tunnel project,and the safety criterion of blasting vibration of dangerous rock mass based on time history analysis method and the calculation method of blasting vibration criterion of dangerous rock mass based on one-dimensional stress wave theory were put forward.The results show that the safety factor of dynamic stability of dangerous rock mass is affected by the maximum single response charge and blasting center distance.When the size of dangerous rock mass exceeds the wavelength of blasting seismic wave,the attenuation effect of blasting vibration frequency and phase difference should be considered.Through the analysis and comparison of the two criterion methods,it is suggested that the maximum allowable vibration velocity in the dangerous rock area of Baiyanshan tunnel should be controlled according to[V]=0.57cm/s.The research results have important reference value for similar projects.