水下钻孔爆破减震安全技术及应用

介绍了广西贵港电厂取水泵房进水前池基岩水下钻孔爆破技术方案。该方案采用微差爆破技术,段间时间间隔≥50 ms,炮孔直径100 mm,孔距1.5m;排距1.2 m,平均孔深3 m,炸药单耗1.2 kg/m3,并在距水泵房前沿8 m处布设2排预裂减震孔,孔径110 mm,孔距0.5 m,排距1.2 m,孔深7 m。为了降低爆破引起的水冲击波对取水泵房的影响,还在取水泵房前沿5 m外设置1道水下空气帷幕。爆破施工实践表明,该方案有效降低了水下爆破对相距不足10 m的近距离取水泵房的振动影响,保障了取水泵房的安全。

Safety Technique and Application of Shock Absorption in Underwater Drilling and Blasting

The underwater drilling and blasting scheme of forebay of water intaking pump station was introduced at Guigang power plant in Guangxi.The Millisecond delay blasting was used with greater than 50ms,meanwhile,the hole diameter is 100 mm,the hole spacing is the 1.5 m and 1.2 m,and the average depth is 3 m,and the specific charge is 1.2 kg/m3.There are also two rows pre-splitting hole before the pump station,which the hole diameter is 110 mm,the spacing is 0.5 m and the row spacing is 1.2 m,the depth is 7 m.For reducing influence of blast water shock wave on the pump station,an underwater bubble curtain 5 m away from the water intake pump station outside was set up.The construction practice proves that this method can reduce effectively the underwater blasting vibration influence on pump station away less than 10m from the blast area and ensures the safety of the pump station.