【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。更多还原

【Abstract】 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 nearsource wave field study and improvement of excitation effect.更多还原