大规模冰水堆积体钻爆开挖参数优化理论与试验研究

Theoretical and Experimental Study on Parameter Optimization for Blasting Excavation of Large Outwash Accumulation

大型冰水堆积体颗粒物质组成复杂,胶结特性各异,且空间分布不均,开挖过程中普遍存在爆破效果差、效率低的问题。结合梨园水电站下咱日冰水堆积体开挖,基于爆破漏斗理论分析、室内实验和现场试验,对其钻爆开挖参数及施工技术开展研究,结果表明:冰水堆积体按其物理力学性质和施工特性可分为强胶结、较致密弱胶结和较松散弱胶结3级;强胶结冰水堆积体的最优抵抗线宜为2.5～3.5m,孔深为2～3m,炸药单耗为0.3～0.35kg/m3;弱胶结冰水堆积体的最优抵抗线宜为3m和4m,孔深为3～4m,炸药单耗为0.28～0.3kg/m3;提出了采用高风压钻机钻孔、φ70药卷、3～4m浅台阶和平面大面积多点爆破的施工技术。研究成果在下咱日冰水堆积体开挖工程中应用效果良好,可为西南地区的大型冰水堆积体开挖施工提供参考。

The problem of poor blasting effect and low efficiency is widespread in the excavation of large outwash accumulation,which has complex composition of particulate matter,different cementation characteristics and uneven spatial distribution.With the excavation of Xiazanri outwash accumulation in Liyuan hydropower station,the drill blasting excavation parameters and construction technology were researched based on the blasting crater theory analysis,indoor experiment,and field test.The results showed that the outwash accumulation could be classified into three levels of strong cementation,compact weak cementation,and weak cementation,based on its physical mechanical property and construction characteristic.The optimal resistance should be 2.5~3.5 m,the hole depth should be 2~3 m and the explosive consumption should be 0.3~0.35 kg/m3 for strong cemented outwash accumulation.The optimal resistance should be 3m or 4 m,the hole depth should be 3~4 m and the explosive consumption should be 0.28~0.3 kg/m3 for weakly cemented outwash accumulation.The blasting technology of using high air pressure drilling rig,φ70 cartridge,plane area multipoint blasting and shallow stair of 3~4 m was raised.The results applied well in the excavation of Xiazanri outwash accumulation and it could be used as a reference for the excavation construction of large outwash accumulation in the southwest.