地雷对地表声阻抗率的影响研究
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摘要
设计一种基于地震检波器的实验系统,分析地雷对地表声阻抗率的影响。用音响发射扫频的正弦声波穿透到地下土壤,用声级计和地震检波器分别测得地表声压级和振动速度。测试数据显示,没有地雷的地表声阻抗率与有地雷的比值在72,140Hz处出现2个极大值,用相长干涉原理和地雷与其上方土壤的谐振作用解释了这一现象。结果表明:地雷能在较宽频带内减小地面声阻抗率,所设计的实验系统可用于声波探雷的进一步研究。
A geophone-based experimental system is designed to analyze landmines’impact on earth surface acoustic impedance.Loudspeaker is used to insonify a swept sine tone over the soil.Sound level meter and geophone are respectively adopted to measure the applied acoustic pressure level and the induced vibration velocity at the surface.The experimental data shows that the ratio of surface acoustic impedance off-to-on mine appears two peak values at 72Hz and 140Hz.Constructive interference theory and resonance mechanism between the mine and the soil on top of its are used to explain such phenomenon.The results indicate that landmines decrease the surface acoustic impedance within a wider frequency range and the presented system can be used to further experimental study of acoustic landmines detection.
A geophone-based experimental system is designed to analyze landmines’impact on earth surface acoustic impedance.Loudspeaker is used to insonify a swept sine tone over the soil.Sound level meter and geophone are respectively adopted to measure the applied acoustic pressure level and the induced vibration velocity at the surface.The experimental data shows that the ratio of surface acoustic impedance off-to-on mine appears two peak values at 72Hz and 140Hz.Constructive interference theory and resonance mechanism between the mine and the soil on top of its are used to explain such phenomenon.The results indicate that landmines decrease the surface acoustic impedance within a wider frequency range and the presented system can be used to further experimental study of acoustic landmines detection.
引文
[1]Biot MA.Theory of propagation of elastic waves in a fluid-satu-rated porous solid:I Low-frequency range[J].J Acoust Soc Am,1956,28(2):168-178.
[2]Biot MA.Theory of propagation of elastic waves in a fluid-satu-rated porous solid:ⅡHigher-frequency range[J].J Acoust Soc Am,1956,28(2):179-191.
[3]Sabatier J M,Bass HE,Bolen L N.Acoustically induced seismic waves[J].J Acoust Soc Am,1986,80(2):646-649.
[4]Sabatier J M,Bass H E,Bolen L N.The interaction of airbornesound with the porous ground:The theoretical formulation[J].J Acoust Soc Am,1986,79(5):1345-1352.
[5]杨顶辉.双相各向异性介质中弹性波方程的有限元解法及波场模拟[J].地球物理学报,2002,45(4):575-583.
[6]裴正林.三维双相各向异性介质弹性波方程交错网格高阶有限差分法模拟[J].中国石油大学学报:自然科学版,2006,30(2):16-20.
[2]Biot MA.Theory of propagation of elastic waves in a fluid-satu-rated porous solid:ⅡHigher-frequency range[J].J Acoust Soc Am,1956,28(2):179-191.
[3]Sabatier J M,Bass HE,Bolen L N.Acoustically induced seismic waves[J].J Acoust Soc Am,1986,80(2):646-649.
[4]Sabatier J M,Bass H E,Bolen L N.The interaction of airbornesound with the porous ground:The theoretical formulation[J].J Acoust Soc Am,1986,79(5):1345-1352.
[5]杨顶辉.双相各向异性介质中弹性波方程的有限元解法及波场模拟[J].地球物理学报,2002,45(4):575-583.
[6]裴正林.三维双相各向异性介质弹性波方程交错网格高阶有限差分法模拟[J].中国石油大学学报:自然科学版,2006,30(2):16-20.
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