摘要
Abstract
To investigate the influence of hole layout schemes for cut blasting in one-time blind raise sinking with medium-deep holes on blasting performance,taking a tin mine project in Yunnan as the engineering background,the finite element numerical simulation technology of LS-DYNA was adopted to compare and analyze the damage area of cut cavity cross-section and excavation advance under five different hole layout patterns.The optimal hole layout scheme was screened out and verified via field tests.The results show that Scheme 1(9-hole cylindrical cut)achieves a total blasting damage area of 16.03 m2 and an excavation advance of 883 cm,making it the optimal scheme,followed by Scheme 5,while Scheme 4 exhibits the worst performance.Compared with Scheme 5,the damage area and excavation advance of Scheme 1 increase by 1.84％and 1.73％,respectively;compared with Scheme 4,they rise by 26.9％and 4.6％.Its comprehensive blasting efficiency surpasses other schemes.Field tests carried out on the optimal layout scheme indicate that the actual raise forming height matches the designed height,the cut cavity presents regular shape without obvious oversize rock blocks.For blind raise blasting excavation under similar geological conditions of medium-stable marble,this scheme can improve the cycle efficiency by 3％～5％and reduce ineffective explosive consumption by more than 15％.It provides a reference for the selection of hole layout patterns for one-time blind raise forming by medium-deep hole blasting.关键词
数值模拟/盲天井/掏槽爆破/一次成井/布孔Key words
numerical simulation/blind raise/cut blasting/one-step raise excavation/drill-hole layout layout分类
矿业与冶金
