Abstract Continuous estimates of penetrometer resistance (Q) would be useful in root elongation and in soil management studies. However, penetrometers produce estimates of penetration resistance at discrete time points. In this paper, a method with the potential to provide continuous estimates of penetrometer resistance is developed. We use measurements of soil water content, shear wave velocity (Vs) determined from piezo electric devices, and bulk density (ρb) determined with the heat pulse (HP) method, to estimate penetrometer resistance. Soil samples of a loamy sand were packed into cylinders with axial pressures of 50, 100, and 200 kPa, and allowed to equilibrate at matric potentials of −2, −6, −10, −30, −100, −300, and −500 kPa. Thermal conductivity (λ), Vs and Q were measured after equilibration. A λ-based approach was applied to estimate ρb, and small strain shear modulus (G) was calculated from ρb and Vs. Our results confirmed a linear relationship between Q and G (where G = Vs2ρb), which provides a basis to estimate penetrometer data in the field using buried sensors and a physically based model.

中文翻译：

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从含水量、体积密度和剪切波速度估计土壤渗透计阻力的新方法：对壤质砂土的实验室研究

摘要 针入度电阻 (Q) 的连续估计在根伸长和土壤管理研究中非常有用。然而，渗透计在离散时间点产生渗透阻力的估计值。在本文中，开发了一种方法，该方法具有提供针入度电阻连续估计的潜力。我们使用土壤含水量的测量值、由压电设备确定的剪切波速度 (Vs) 和通过热脉冲 (HP) 方法确定的体积密度 (ρb) 来估计穿透计电阻。将壤质沙土样品装入轴向压力为 50、100 和 200 kPa 的圆柱体中，并使其在 -2、-6、-10、-30、-100、-300 和 - 的基质势下平衡500千帕。在平衡后测量热导率 (λ)、Vs 和 Q。一种基于 λ 的方法被用于估计 ρb，小应变剪切模量 (G) 由 ρb 和 Vs 计算。我们的结果证实了 Q 和 G 之间的线性关系（其中 G = Vs2ρb），这为使用埋地传感器和基于物理的模型估计现场穿透计数据提供了基础。