浅孔台阶爆破的合理性研究  

Study on Rationality of Shallow Hole Bench Blasting

作　　者：杨琳 付天杰[2] 郭华杰 YANG Lin;FU Tian-jie;GUO Hua-jie(Shenzhen Antuoshan Investment&Development Co.,Ltd.,Shenzhen 518040,China;Chinese Academy of Railway Science Beijing,Beijing 100081,China)

机构地区：[1]深圳市安托山投资发展有限公司,深圳518040 [2]中国铁道科学研究院,北京100081

出　　处：《爆破》2022年第1期87-94,共8页Blasting

摘　　要：在台阶爆破中,台阶高度增加到一定值后,需保持孔排距不变,以优化爆破效果。在现场针对三种不同孔径及不同台阶高度的爆破进行试验,得到孔径76 mm的浅孔台阶爆破较深孔台阶单耗低,台阶高度小于12 m时,单耗随台阶高度变化大,当台阶高度大于12 m时,单耗变化率变小,此时宜进行爆前准备阶段爆破参数优化。为便于在现场直接根据台阶高度优化爆破参数,对三种不同孔径、不同高度台阶爆破后总结提出高抗比,并进行了长径比,长抗比的对比分析,提出其合理爆破系数。在邻近保护物位置爆破时,采用孔径76 mm的浅孔台阶爆破,装药长径比为25~43,对应长抗比为0.86~1.5,对应高抗比为1.59~2.27;对孔径76 mm的深孔台阶爆破,装药长径比为108~134,对应长抗比为3.28~4.08,对应高抗比为4~4.8;对孔径115 mm的深孔台阶爆破,装药长径比为22~64,对应长抗比为0.74~2.06,对应高抗比为1.5~2.78;对孔径140 mm的深孔台阶爆破长径比及高抗比不易控制,应用少。针对总爆破进行了年度成本累计分析,得到钻孔成本占到总成本的59%左右,并提出了降低爆破成本的方法。In bench blasting,when bench height increases to a certain value,the spacing between rows of holes should be kept constant to optimize the blasting effect.Three blasting experiments were conducted with different hole diameters and bench heights in the field.It is found that the shallow-hole bench blasting with a hole diameter of 76 mm has lower powder factor than that of the deep-hole bench blasting.More specifically,the change rate of powder factor is lower with the bench height more than 12 m compared to that with the bench height smaller than 12 m,at which time it is suitable to optimize the blasting parameters in the pre-blasting preparation stage.In order to optimize the blasting parameters according to the bench height on site,three post-blast cases with different hole diameters and bench heights were analyzed and the ratio of bench height/burden was presented.At the same time,the ratios of charge length/hole diameter and charge length/burden were compared in order to determine reasonable blasting parameters.When the blast is conducted near the object to be protected,a shallow hole bench blasting with a hole diameter of 76 mm is used.The corresponding ratios of charge length/hole diameter,charge length/burden and bench height/burden are in the ranges of 25~43,0.86~1.5 and 1.59~2.27,respectively.In other cases,for the deep hole bench blasting with a hole diameter of 76 mm,the aforementioned ratios are in the ranges of 108~134,3.28~4.08 and 4~4.8,respectively.For the deep hole bench blasting with a hole diameter of 115mm,the aforementioned ratios are in the ranges of 22~64,0.74~2.06 and 1.5~2.78,respectively.However,it is not easy to control the ratios of charge length/hole diameter and bench height/burden for the deep hole bench blasting with a hole diameter of 140 mm,and thus the application is rare.Finally,a cumulative annual blast cost analysis was carried out,and it is found that the drilling cost accounts for about 59%of the total cost.Besides,a method to reduce the blasting cost was proposed.

关 键 词：浅孔台阶爆破 高抗比 长径比 台阶高度 长抗比 大块率 

分 类 号：TU746.5[建筑科学—建筑技术科学]