锦屏一级水电站左岸抗力体爆破开挖振动监测总结

Summary on the Monitoring of Vibration Caused by Blasting Excavation of Force-resisting Mass on the Left Bank of Jinping First Stage Hydropower Project

根据锦屏一级水电站左岸抗力体处理开挖的特点,在实测质点振动速度和宏观调查等手段的基础上,提出了爆破对排水洞、帷幕洞、置换洞、置换斜井影响沿其振动最大方向振动传播规律的经验公式,以及保证爆破对相邻洞新浇混凝土的影响满足要求的措施。实验结果表明,坝基排水洞的振动控制是重点,最大单段药量以及掏槽孔轴向与洞轴向夹角适当,并在合理安排相关部位开挖与支护时段的情况下,就可以满足相应的安全控制标准,但为安全起见,仍应从严控制最大单段药量。此外,还对爆破振动的控制以及影响振动峰值大小的因素等进行了进一步的分析,可供类似工程开挖参考。

On the basis of measuring particle vibration velocity and macroscopic investigation of the force-resisting mass on the left bank of Jinping first stage hydropower project,we proposed the empirical formula of vibration spread regularity and the measures of controlling blasting vibration of the adjacent tunnel＇s newly casted concrete.Testing results show that vibration control for the drainage hole of dam foundation is crucial.If the maximum explosive quantity of single shot as well as the angle included between cut hole＇s axial direction and tunnel＇s axial direction are suitable,and if the excavation and supporting time is rationally arranged,the safety controlling standard can be met.But for the sake of safety,the maximum explosive quantity of single shot should be strictly controlled.Furthermore,blasting vibration control and factors affecting the peak vibration velocity are analyzed.This research is a reference for similar engineering excavation.