【摘要】 本文介绍了南芬露天矿由于岩层倾斜较缓（40°～50°），致使下盘台阶坡面角减小，底盘抵抗线较大，爆破后易残留根底。为此，本文推荐了俄罗斯使用火钻扩孔法，以增大孔店装药量，在不增加超深的情况下，克服根底的经验。该法还可以提高生产率和降低成本。更多还原

【Abstract】 This article introduas tha due to the long toe burder and the smaller angle of foowall benches for thesmaller angle (40°～50°) of seams in Nanfen pen-pit Mine. Por this, author recommendes the successfulexperiences with thermal chambering of blast holos in Russia for overcondng the tightbottoms by increasingexplodve charge and without deepening the ovetdrill. By this method the productivity will be increaed andthe cest cut will be achived also.更多还原