高陡边坡爆破对下方洞室的振动影响

以长河坝水电站泄洪放空系统及中期导流洞工程出口边坡爆破开挖为背景,分析了边坡爆破地震波对下邻地下洞室安全的影响。运用理论分析及现场监测等方法,在充分分析现场工程条件的基础上,确定了放空洞和3#泄洪洞的振动测点位置,共获得了21组爆破振动测试数据。结果表明:放空洞底脚处峰值振速为垂直方向4.32cm/s;3#泄洪洞洞壁距底板0.5m处的峰值振速为水平方向4.05cm/s;洞室与爆区的相对空间位置不同,其峰值振速所在的方向不同。认为尽管边坡爆破位于洞室群的上方且距离较近,但只要爆破方案及其参数控制得当,可以保证洞室群安全。

Vibration impact of high-steep slope blasting on the underground chamber

Based on the blasting excavation of the Changheba hydropower station and the excavation of the slope of the middle diversion tunnel,the impact of the slope blasting seismic wave on the safety of the underground chamber was analyzed.Based on the method of theoretical analysis and site monitoring,the vibration measurement points of the emptying tunnel and the 3# spillway were determined,and 21 sets of blasting vibration test data were obtained.The results showed that the peak velocity was 4.32 cm/s in the vertical direction,and the peak velocity of the 3# spillway tunnel was 0.55 cm/s from the bottom plate at 0.5 m;when the relative space position of the chamber and blasting area were different,the peak vibration velocity would be in different direction.We believe that,the slope blasting located close above the chambers,but as long as the blasting program and the parameters can be controlled properly,the champers would be safe.