A novel approach to estimate soil penetrometer resistance from water content, bulk density, and shear wave velocity: A laboratory study on a loamy sand soil
A novel approach to estimate soil penetrometer resistance from water content, bulk density, and shear wave velocity: A laboratory study on a loamy sand soil
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DOI：
10.1016/j.geoderma.2020.114276
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发表时间：
2020-06
期刊：
影响因子：
6.1
通讯作者：
Wencan Zhang;Weida Gao;T. Ren;W. R. Whalley
中科院分区：
文献类型：
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作者：
Wencan Zhang;Weida Gao;T. Ren;W. R. Whalley
连续估计穿透电阻(Q)在根系伸长和土壤管理研究中是有用的。然而，穿透计在离散时间点产生穿透阻力的估计。本文提出了一种具有提供贯入电阻连续估计潜力的方法。我们使用测量土壤含水量，由压电装置测定的剪切波速（Vs）和用热脉冲（HP）方法测定的体积密度（ρb）来估计穿透计电阻。将壤土样品装入轴向压力为50,100和200kpa的圆柱体中，并在- 2，- 6,- 10,- 30,- 100，- 300和- 500 kPa的基质电位下进行平衡。平衡后测量导热系数（λ）， vsandq。采用基于a λ的方法估计ρb，由ρ bandv计算小应变剪切模量G。我们的研究结果证实了qandg（其中g =Vs2ρb）之间的线性关系，这为使用埋藏传感器和基于物理的模型估计现场渗透率数据提供了基础。
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),VsandQwere measured after equilibration. Aλ-based approach was applied to estimateρb, and small strain shear modulus (G) was calculated fromρbandVs. Our results confirmed a linear relationship betweenQandG(whereG=Vs2ρb), which provides a basis to estimate penetrometer data in the field using buried sensors and a physically based model.