ACOUSTIC FLUIDIZATION - NEW GEOLOGIC PROCESS
ACOUSTIC FLUIDIZATION - NEW GEOLOGIC PROCESS
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DOI：
10.1029/jb084ib13p07513
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发表时间：
1979-01-01
影响因子：
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通讯作者：
MELOSH, HJ
中科院分区：
文献类型：
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作者：
MELOSH, HJ
许多地质过程，特别是地震断层、撞击坑滑塌和长距离滑坡，要求地质材料在比传统岩石力学所预期的小得多的差应力下发生破坏。本文提出，在这些现象中明显的低强度是由于一个瞬态强声波场引起的“声流化”状态。在这样一个领域的应变率可能进行评估，它表明，声学流化碎片的行为作为一个牛顿流体的粘度在105- 107 P的范围内的合理条件。能量的增益和损失在声场中进行了讨论，并示出的机制是有效的，如果在该领域的内部耗散给aQ = 100。目前还不知道Q的这些值是否实现了。然而，声波流化提供了一个定性的正确的描述故障的岩石碎片在低差应力的过程中的断层，火山口滑塌，和长径流滑坡。因此，声学流化作为这些现象的一种可能的解释值得认真考虑。
A number of geologic processes, particularly seismic faulting, impact crater slumping, and long runout landslides, require the failure of geologic materials under differential stresses much smaller than expected on the basis of conventional rock mechanics. This paper proposes that the low strengths apparent in these phenomena are due to a state of ‘acoustic fluidization’ induced by a transient strong acoustic wave field. The strain rates possible in such a field are evaluated, and it is shown that acoustically fluidized debris behaves as a newtonian fluid with a viscosity in the range 105–107P for plausible conditions. Energy gains and losses in the acoustic field are discussed, and the mechanism is shown to be effective if internal dissipation in the field gives aQ≳ 100. Whether such values forQare realized is not known at present. However, acoustic fluidization provides a qualitatively correct description of the failure of rock debris under low differential stresses in the processes of faulting, crater slumping, and long runout landslides. Acoustic fluidization thus deserves serious consideration as a possible explanation of these phenomena.