斷頂爆破在堅硬頂板條件下的沖擊礦壓災害防治中應用廣泛?；趧屿o載疊加原理，理論分析了斷頂爆破防治沖擊礦壓的作用機制，在對沖擊危險預評估和沖擊危險動態演化特點分析的基礎上，揭示了沖擊危險具有分時、分區和分級的“三分”特征，建立了分時、分區、分級斷頂爆破防治沖擊礦壓技術體系，應用于堅硬頂板型沖擊礦壓防治工程實踐，并通過采取理論計算、鉆屑監測和微震監測手段進行斷頂爆破效果評價。結果表明：爆破后形成的裂隙區貫通為連續的弱面是控制沖擊礦壓最重要的區域，斷頂爆破能夠減弱由于頂板瞬間破斷或垮落釋放的動載強度，降低上覆懸頂施加在煤體內的靜載強度并促使煤體峰值應力向工作面前方轉移，達到降低沖擊礦壓危險的目的；依據揭示的沖擊危險分時、分區、分級的“三分”特征，建立了“開切眼傾向斷頂爆破、臨空煤柱側走向斷頂爆破、工作面內超前預裂爆破和及時解危斷頂爆破”的分時分區分級斷頂爆破防治沖擊礦壓技術體系，相應進行了斷頂效果評價，其中開切眼傾向斷頂爆破后工作面初次來壓和周期來壓階段頂板聚集的能量分別降低72%和76%；臨空煤柱側斷頂爆破后煤柱內鉆屑值下降0.55 kg/m；工作面內預裂爆破區域在回采期間出現微震總能量、單日最大能量均明顯降低，微震頻次顯著增加的整體規律，驗證了分時分區分級斷頂爆破技術體系對防治沖擊礦壓的有效性。

Break-tip blasting is widely used in the prevention and control of rock burst under the condition of hard roof.Based on the mechanism of rock burst induced by static and dynamic loading,the mechanism of break-tip blasting to prevent rock burst is analyzed.Based on the analysis of the pre-assessment and dynamic evolution characteristics of the rock burst,the time-space-level division characteristics of rock burst is revealed,a technology system of time-space-level division break-tip blasting to prevent rock burst is proposed,which is applied to the engineering practice of rock burst prevention with hard roof,and it through theoretical calculation,drilling cuttings monitoring and microseismic monitoring to evaluation of break-tip blasting effect.The results show that the continuous weak surface consisted of fracture zone is the most important area to control the rock burst,the break-tip blasting can reduce the dynamic load strength released by the instantaneous breaking or collapsing of the roof,reduce the static load level imposed by suspended roof in coal,and promote the peak stress of the coal to transfer to the front of the working face,which can reduce the risk of rock burst.Based on the characteristics of "three parts" of time-space-level division of rock burst,a time-space-level division technology system for prevention and control of rock burst is established,which includes inclined break-tip blasting in cutting hole,strike break-tip blasting in coal pillar,pre-splitting blasting in working face and breaking-tip blasting in time.The system is applied to engineering practice and the effect of breaking-tip is evaluated,in which the flexural elasticity of roof decreases by 72% and 76% respectively in the initial weighting and periodic weighting after inclined break-tip blasting in cutting hole; the average amount of drilling cuttings decreases by 0.55 kg/m after strike break-tip blasting in coal pillar; the total energy and the maximum energy per day of microseisms in the presplitting blasting area of the working face are obviously reduced and the frequency of microseisms is significantly increased during the mining period.The effectiveness of time-space-level division break-tip blasting technology system to prevent rock burst is verified.