预裂爆破在高边坡梯段开采中的应用

Application of the presplit blasting to the excavation or high side-slope bench

在漫湾水电站人工砂石料生产中建立预裂破碎带的方法对露天台阶开采终采边坡进行保护，达到一次成型，保证了终采边坡前的主爆孔在大孔径药包条件下爆破对边坡壁面不产生破坏，提高了施工进度和为主爆孔大规模爆破创造了条件。通过实践得出了适用于该地质条件下的经验公式，为２００ｍ以上高边坡的综合治理提供了一种参考方法。

In the production of artificial aggregate for Manwan Hydropower Station, the final slope of the excavation of open terrace has been protected by the method of forming presplit crushed zone, which has formed the final shape by only one presplit blasting. It has ensured that the side-slope wall could not be destroyed when the blasting of main blasthole before the final excavation safe-slope is conducted under the condition of large-diameter powderbag. Then the construction progress has been quickened and the favorable conditions have been,created for thelarge-scale blasting in the main blasthole. In the practice, the empirical formula have been gained,which are applicable to similar geological conditions. The presplit blasting has produced notable economic benefits and ideal results,which has provided a reference method for the excavation of high side-slope with over 200m.