摘要
为进一步讨论双孔微差爆破及柱状药包爆破振动新特性,通过在空腔内壁施加等效爆源荷载方法,建立药包爆破振动LS-dyna数值模拟模型,分别对双孔微差爆破和长柱状药包爆破振动进行分析。通过控制加载时间模拟不同延时间隔下的微差爆破过程,同时建立不同长度的加载组元来表示柱状装药的药包长度,进而研究药包长度对爆破振动的影响。数值模拟结果与相应的理论计算结果具有较好的一致性。结果表明:微差爆破质点峰值速度与距离整体呈现负相关,但在衰减过程中出现局部的增大现象,增大的幅值和区间与延时间隔有关,间隔时间越长,局部放大效应距离爆源越远,放大幅值越小。对长柱药包的模拟结果则表明:对于介质中某一点,当药包长度达到特定值后,质点峰值速度将不随着药包长度的增长而增大,这表明传统的通过药量来衡量爆破振动幅值的计算方法具有一定局限性。这些成果对爆破振动预测及爆破施工设计具有一定指导意义。
The LS-dyna numerical simulation model of blasting vibration is built by applying an equivalent explosive source load on the inner wall of cavity to further study double-hole millisecond blasting and cylindrical charge blasting. The new vibration characteristics of double-hole millisecond blasting and cylindrical blasting are discussed respectively. The delay interval time of double-hole millisecond blasting numerical model is controlled by loading time. At the same time, the loading components with different length are established to simulate charge length of long charge blasting vibration. The simulation results fit the corresponding theoretical calculation results well. Results show that the peak particle velocity （PPV） of millisecond blasting has significantly negative correlation with the distances. While local PPV increasing phenomenon is found during the decay process, and the increase of amplitude and range are related to the interval time. The longer the interval time is the larger the distance between blasting source and lo- cal amplification phenomenon is and the smaller the increase amplitude is. The simulation results of long cylindrical charge show that the PPV of certain point in the medium wouldn＇t increase with the charge length wben the charge length reaches a certain value,which show the defect of common calculation method. These results are quite significant for the blasting vibration prediction and design.
出处
《爆破》
CSCD
北大核心
2017年第3期46-52,共7页
Blasting
基金
国家自然科学基金(11672112)
高等学校博士学科点专项科研基金(20113718110002)
爆炸冲击防灾减灾国家重点实验室开放课题(DPMEIKF201307)
华侨大学科研基金项目(13BS402)
关键词
爆破振动
微差爆破
柱状药包
数值模拟
blasting vibration
millisecond blasting
cylindrical charge
numerical simulation
