摘要
依托老挝南俄1水电站扩机工程爆破开挖,选取已有典型建筑设备,开展爆破振动跟踪监测,基于统计数据对比分析了主爆孔与预裂孔诱发爆破振动的差异;借助光滑粒子流(SPH)数值计算方法,从装药结构、起爆方式及抵抗线大小三个方面,分析了造成主爆孔与预裂孔爆破振动差异的原因。结果表明:预裂孔诱发的爆破振动峰值水平普遍高于主爆孔;装药结构、起爆方式和抵抗线大小均会影响爆破加载特性和爆破近区损伤的演化与分布,进而引起爆炸能量传输与分配的不同;预裂孔一般采用不耦合装药,并通常由导爆索侧向起爆,抵抗线也较大,其炮孔壁上的爆破荷载峰值低于主爆孔,炮孔附近的粉碎区范围和裂纹数量较少,且抵抗线方向上的岩石损伤程度较低,从而消耗于岩石破碎和抛掷的能量占比更小,使得更多的能量转化为振动能,故而预裂爆破诱发的振动水平要高于主爆孔。
On the background of the extension of Nam Ngum 1 Hydropower Station in Laos,the blast vibration tracking of the existed buildings and equipment was implemented.The vibration characteristics of presplitting blast-holes and main blast-holes were compared by analyzing the statistical data.Besides,the smoothed particle hydrodynamics(SPH)numerical technique was used to study the causes of the vibration differences induced by presplitting blast-holes and main blast-holes from the views of charging structures,initiation modes and burden sizes.Results indicate that the peak particle velocity(PPV)induced by presplitting blast-holes is generally higher than that induced by main blast-holes.The charging structures,initiation modes and burden sizes all play a significant role on the explosion loading characteristics as well as the evolution and distribution of the nearfield blast damage,which further affects the transmission and distribution of explosion energy.The explosives in presplitting blast-holes are generally decoupled charging with the rock mass and laterally initiated by the detonating cord.Moreover,the burden of presplitting blast-holes is always larger than that of main blast-holes.The peak blasting pressure on presplitting blast-hole walls is lower than that on main blast-hole walls.For the presplitting blast-holes,the crush zone and the number of cracks adjacent to the blast-hole,as well as the damage degree of the rock mass along the resistance direction,are all relative smaller.Thus,less explosion energy is consumed by rock fragmentation and throwing,allowing more energy to be converted into vibration energy.Consequently,the vibration induced by presplitting blast-holes is relative larger than that induced by main blast-holes.
作者
周海孝
高启栋
王亚琼
冷振东
陈明
ZHOU Hai-xiao;GAO Qi-dong;WANG Ya-qiong;LENG Zhen-dong;CHEN Ming(School of Highway,Chang′an University,Xi′an 710064,China;Gezhouba Group Explosive Co.,Ltd.,Chongqing 401121,China;Key Laboratory of Rock Mechanics in Hydraulic Structural Engineering Ministry of Education,Wuhan University,Wuhan 430072,China)
出处
《爆破》
CSCD
北大核心
2021年第2期58-66,共9页
Blasting
基金
国家自然科学基金(52009003、51809016)
中央高校基本科研业务费专项基金(300102210123)
水工岩石力学教育部重点实验室开放研究基金(EMHSE1903)。
关键词
水电站扩机
爆破振动
预裂孔
主爆孔
振动特性
extension of hydropower station
blast vibration
presplitting blast-holes
main blast-holes
vibration characteristic
