摘要
自然岩体往往是含有节理、裂隙、断层等地质结构面的不连续介质,岩体的这种不连续性对预裂爆破时应力波的传播和预裂缝的形成都具有重要影响。为了研究节理走向角度对预裂缝贯通程度的影响,对一次预裂爆破所生成的预裂缝进行分段爆破振动测试试验,通过不同段的节理走向角度与降振率的结果发现:炮孔间节理走向角度对预裂成缝的影响显著,预裂爆破所在位置的节理走向角度越大,该位置上所产生预裂缝的降振率越高,表明预裂缝的贯通程度随节理走向角度的增大而提高。观察现场预裂爆破效果也发现:当节理面走向角度接近90°时,预裂缝的贯通性与平整度最好,与理论分析基本一致。
Natural rock mass usually contains discontinuous medium in geological structural planes such as joints, fissuring,faults etc. The discontinuity of rock mass has both important influences on the spread of stress wave and the formation of pre-cracking during the pre-splitting blasting. In order to investigate the effect of angle of joints strike on the cut-through degree of the pre-crackings, the segmented blasting vibration tests for the pre-crackings generated are made during once pre-splitting blasting. It has been found through the angle of joints strike and the decreasing vibration rate of different sections that the angle of joints strike between blast holes has a significant influence on pre-eracking;the bigger the angle of joints strike in the loca- tion of the pre-splitting blasting,the higher the decreasing vibration rate of the generated pre-cracking at that location. The cut through degree is increased as the angle of joints strike increases. Through observing the effect of pre-splitting blasting on site, it is clear that when the angle of strike of joints plan gets close to 90~ ,the pre-craeking will have a best penetrating and flat- ness,which is almost consistent with the theoretical analysis.
出处
《金属矿山》
CAS
北大核心
2014年第4期6-11,共6页
Metal Mine
关键词
预裂爆破
预裂缝
节理岩体
节理面走向角度
分段降振试验
Pre-splitting blasting, Pre-eracking, Jointed rock mass, Joint surface angle of strike, Segmented decreasing vi- bration test
