Acoustic response of cemented granular sedimentary rocks: molecular dynamics modeling.
Acoustic response of cemented granular sedimentary rocks: molecular dynamics modeling.
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胶结颗粒沉积岩的声学响应：分子动力学建模。
DOI：
10.1103/physreve.75.061308
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
Ernesto Antonio Medina Dagger
中科院分区：
文献类型：
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作者：
X. Garcia;Ernesto Antonio Medina Dagger
采用分子动力学模拟方法研究了胶结过程对砂土声学性质的影响。我们提出了通过模拟泥沙的沉降过程来建立初始无胶结砂的数值方法。不同孔隙度的未胶结样品通过模拟沉积物由于覆盖层的自然机械压实而被考虑。胶结作用是通过基于粒子的模型来考虑的，该模型捕捉了过程背后的潜在物理原理。在我们的模拟中，我们考虑了不同压实程度的样品和具有不同弹性特性的胶结材料。在气孔内的特定位置(如颗粒与颗粒的接触)加入水泥时，会考虑胶结砂的微观结构。结果表明，胶结砂的声学特性强烈地依赖于水泥用量、其相对于宿主介质的硬度以及其在孔隙中的位置。模拟结果与已有的实验数据吻合较好，并与理论预测的水泥饱和度、孔隙度和围压范围内的声速有较好的一致性。
The effect of cementation processes on the acoustical properties of sands is studied via molecular dynamics simulation methods. We propose numerical methods where the initial uncemented sand is built by simulating the settling process of sediments. Uncemented samples of different porosity are considered by emulating natural mechanical compaction of sediments due to overburden. Cementation is considered through a particle-based model that captures the underlying physics behind the process. In our simulations, we consider samples with different degrees of compaction and cementing materials with distinct elastic properties. The microstructure of cemented sands is taken into account while adding cement at specific locations within the pores, such as grain-to-grain contacts. Results show that the acoustical properties of cemented sands are strongly dependent on the amount of cement, its stiffness relative to the hosting medium, and its location within the pores. Simulation results are in good correspondence with available experimental data and compare favorably with some theoretical predictions for the sound velocity within a range of cement saturation, porosity, and confining pressure.