爆炸冲击波及地震子波的形成因素分析
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摘要
炸药震源是陆上地震勘探的主要激发方式,而目前地震勘探中对炸药震源爆炸机理的研究相对较少。本文首先对岩石介质中的炸药爆炸效应所产生的冲击波进行定量研究,得出了爆炸空腔扩展过程中腔壁压力随时间的变化关系;讨论了空腔压力在弹性介质中引起的波动现象并导出了空腔震源所产生地震子波位移的解析解;通过数值算例分析了影响地震子波形成的主要因素;修订了直接引用单位压力脉冲求解地震子波解析解的不足。本文结论对研究近源波场特点、改善地震勘探激发效果具有参考意义。
Dynamite source is one of the main excitation modes adopted in land seismic acquisition. Yet few relevant studies are conducted on explosion mechanism of dynamite source recently. Firstly in this paper,a quantitative study on the shock waves generated by explosive effect in rocks is achieved,and the relationship of cavity pressure varied with time during the process of cavity extension is obtained. Then the wave phenomenon in elastic media caused by cavity pressure is discussed,and the analytical solution of seismic wavelet displacement is derived. Finally the factors which influence the forming of seismic wavelets are analyzed based on model tests,and defects caused by commonly used unit impulse are modified. This is meaningful to nearsource wave field study and improvement of excitation effect.
Dynamite source is one of the main excitation modes adopted in land seismic acquisition. Yet few relevant studies are conducted on explosion mechanism of dynamite source recently. Firstly in this paper,a quantitative study on the shock waves generated by explosive effect in rocks is achieved,and the relationship of cavity pressure varied with time during the process of cavity extension is obtained. Then the wave phenomenon in elastic media caused by cavity pressure is discussed,and the analytical solution of seismic wavelet displacement is derived. Finally the factors which influence the forming of seismic wavelets are analyzed based on model tests,and defects caused by commonly used unit impulse are modified. This is meaningful to nearsource wave field study and improvement of excitation effect.
引文
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[5]林大超,白春华.爆炸地震效应.北京:地质出版社,2007
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[7]鲍姆著;众智译.爆炸物理学.北京:科学出版社,1963
[8]Jone H,Miller A R.The detonation of solid explo-sive:the equilibrium conditions in the detonationwave-front and the adiabatic expansion of the prod-ucts of detonation.Proc Roy Soc London,1948,194A(1):480～507
[9]Biot M A.General theory of three-dimensional con-solidation.J Apply Phy,1941,12(2):155～164
[10]成景旺,顾汉明,徐照营.实际地层条件下爆炸震源子波模拟研究.工程地球物理学报,2009,6(5):529～535Cheng Jingwang,Gu Hanming,Xu Zhaoying.Simula-tion of explosion source wavelet in the actual forma-tion.Chinese Journal of Engineering Geophysics,2009,6(5):529～535
[2]张智,刘财,邵志刚.地震勘探中的炸药震源药量理论与实验分析.地球物理学进展,2003,12(4):724～728Zhang Zhi,Liu Cai,Shao Zhigang.Theory and experi-mentation of the charge sizes in seismic-sources forseismic exploration.Progress in Geophysics,2003,12(4):724～728
[3]Miller R D,Pullan S E,Steeples D W et al.Field com-parison of shallow P-wave seismic sources near Hous-ton,Texas.Geophysics,1994,59(11):1713～1728
[4]Sharpe J A.The production of elastic wave by explo-sion pressures.Geophysics,1942,7(2):144～154
[5]林大超,白春华.爆炸地震效应.北京:地质出版社,2007
[6]库尔著;罗耀杰,韩润泽,官志信等译.水下爆炸.北京:国防工业出版社,1960
[7]鲍姆著;众智译.爆炸物理学.北京:科学出版社,1963
[8]Jone H,Miller A R.The detonation of solid explo-sive:the equilibrium conditions in the detonationwave-front and the adiabatic expansion of the prod-ucts of detonation.Proc Roy Soc London,1948,194A(1):480～507
[9]Biot M A.General theory of three-dimensional con-solidation.J Apply Phy,1941,12(2):155～164
[10]成景旺,顾汉明,徐照营.实际地层条件下爆炸震源子波模拟研究.工程地球物理学报,2009,6(5):529～535Cheng Jingwang,Gu Hanming,Xu Zhaoying.Simula-tion of explosion source wavelet in the actual forma-tion.Chinese Journal of Engineering Geophysics,2009,6(5):529～535
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