Estimating Penetrometer Resistance and Matric Potential from the Velocities of Shear and Compression Waves
Estimating Penetrometer Resistance and Matric Potential from the Velocities of Shear and Compression Waves
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DOI：
10.2136/sssaj2012.0394
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发表时间：
2013-05-01
影响因子：
2.9
通讯作者：
Whalley, W. R.
中科院分区：
文献类型：
--
作者：
Gao, W.;Watts, C. W.;Whalley, W. R.
近年来，利用弹性波的速度来推断土体的物理性质引起了人们的兴趣。我们想要验证的是，小应变剪切模数与贯入仪阻力之间存在相对简单的线性关系。我们还对用独立的数据集测试已发表的用于预测剪切波速度的公式感兴趣。本文研究了三种土壤：一种壤质砂土和两种粉质粘壤土。土壤被填塞成垂直轴向应力为30、200或1000 kpa的岩心。饱和后，它们被排出到-10到-500 kpa之间的基质电势范围内。平衡后，我们测量了横波(S波)和纵波(P波)的速度以及渗透仪的电阻。我们的数据证实了先前的一个假设，即贯入仪的阻力是小应变剪切模数的近似线性函数，但通过直接测量验证了这一关系。这些关系对土壤类型有一定的敏感性。然而，我们首次表明，利用S波速通过对土壤类型相对不敏感的校准来推断渗透仪阻力是有相当大的潜力的。尽管用剪切波速或压缩波速估计矩阵势并不是很准确，但在已知空泡率的先验知识的情况下，从弹性波速估计矩阵势的可能性是一个有趣的机会。
Recently there has been interest in using the velocity of elastic waves to deduce soil physical properties. We wanted to validate the suggestion that the small strain shear modulus has a relatively simple linear relationship with penetrometer resistance. We were also interested in testing published equations for predicting shear wave velocity with an independent data set. Three soils were investigated in this study: a loamy sand soil and two silty clay loam soils. The soils were packed into cores with vertical axial stresses of 30, 200, or 1000 kPa. Following saturation, they were drained to a range of matric potentials between -10 and -500 kPa. After equilibration, we measured the velocities of shear (S wave) and compression (P wave) waves as well as the penetrometer resistances. Our data confirmed a previous proposal that the penetrometer resistance was an approximately linear function of the small strain shear modulus but tested the relationship by direct measurement. The relationships were found to have some sensitivity to soil type. Nevertheless, we show for the first time that there is considerable potential for using S wave velocity to deduce penetrometer resistance with a calibration that is relatively insensitive to soil type. Although estimation of the matric potential with either shear or compression wave velocity was found not to be very accurate, the possibility for estimating the matric potential from an elastic wave velocity given a priori knowledge of the void ratio is an interesting opportunity.