大岗山拱坝建基面开挖爆破振动安全监测

Safety monitoring on blasting vibration of excavation of arch dam foundation base

在大岗山水电站拱坝建基面开挖过程中,为寻求科学的爆破控制方法与工艺,按照相关规程规范,对爆破振动进行了跟踪监测。前期跟踪监测分析表明:个别场次的振动监测结果有超标现象。在对超标的原因进行分析之后,提出了改进措施,建基面爆破采取先预裂后主爆的方式,将主爆梯段高度从10 m调整为5 m,同时减少预裂孔的同段起爆孔数和一次开挖爆破的面积,取得了良好的爆破振动控制效果。

In the excavation of dam foundation base of Dagangshan Hydropower Station,the blasting vibration was monitored continuously in order to search for the scientific blasting controlling method and technology,according to the correlative standard.The analysis of pre-stage blasting monitoring showed that some monitored vibrations exceed the standard.After analyzing the causes,the improvement measures were put forward： the main blasting was carried out after the pre-splitting blasting,and the height of the bench for main blasting is reduced from 10 m to 5 m;the ignition holes of the pre-splitting holes in the same section and one-time blasting excavation area were reduced.The measures played an effective role in controlling the blasting vibration.