隧洞爆破开挖对岩质高边坡产生的振动效应研究

针对金佛山水利工程中水工隧洞爆破对左岸岩质高边坡的不利影响,采用有限元数值模拟手段,研究了隧洞爆破对边坡的振动效应,探讨了振动波的传播及分布规律,查明了边坡内部裂隙对振动波传播的影响,根据应力和振速之间的相关性,提出了该边坡的爆破振速的参考安全阀值。结果表明：金佛山水工隧洞爆破开挖对左岸岩质高边坡的振动影响较小,振速峰值未超过规范所规定阀值；由于隧洞爆破和边坡开挖爆破对边坡的坡面振动效应以及传播方向不同,导致爆破振动波通过边坡内部裂隙的传播规律也不同；根据边坡平台内外侧质点的速度分布,借鉴小湾水电站边坡工程,选取平台内侧岩体作为监测部位,根据应力和振速之间的统计规律,得到了左岸岩质高边坡的爆破振速参考安全阀值。

The effects of the adjacent high slope under the condition of the tunnel blasting

In view of the negative influence of the rock slope on the left bank under the condition of the diversion tunnel blasting, the numerical simulation method was used to study the vibration effect of the adjacent rock slope under the condition of the tunnel blasting, the distribution rule of vibration wave and the influence of the cracks in the slope on vibration wave is found out, according to the correlations between stress and vibration velocity, the safety threshold of blasting vibration velocity for this rock slope is obtained. The results indicated that the influence of the rock slope on the left bank under the condition of the diversion tunnel blasting is slightly, the peak value of vibration speed does not exceed the specified threshold specification; because of the different modes of transmission on slope between tunnel blasting and slope excavation blasting, the propagation law of blasting vibration wave when passing through the slope cracks is also different; by comparing the velocity distribution of different positions on the slope platform, and the monitoring point is determined by refereing to the slope of Xiaowan hydropower station, then according to the correlations between stress and the peak particle vibration velocity, the safety threshold of blasting vibration velocity for this rock slope is obtained.