Compressional seismic (P-wave) velocities were measured experimentally at different matric suctions and confining pressure states using a variety of sediments collected from the USDOE Hanford Site in southeastern Washington State. The P-wave velocity was measured in variably saturated sediments using ultrasonic piezoelectric transducers, and matric suction was measured with a heat dissipation sensor. Desaturation of the samples occurred by means of evaporative drying. We propose a model to relate changes in P-wave velocity to soil stress conditions using an effective stress formulation that includes capillary stress as well as adsorptive stress. We show that compressional wave velocities can be related to matric suction and confining stress using a model with five fitted parameters. A single set of parameters describing the relationship between effective stress and P-wave velocity provide an excellent fit to data acquired on Hanford Formation samples. The results presented here suggest the utility of seismic methods for establishing low matric suction and flow conditions within variably saturated Hanford formation sediments, which could be applied at the field scale for evaluating the performance of environmental remediation efforts, such as soil desiccation and surface infiltration barriers.

中文翻译：

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非饱和土壤中的压缩波速度和有效应力：监测包气带沉积物中水分条件的潜在应用

压缩地震（P 波）速度是在不同的基质吸力和围压状态下使用从华盛顿州东南部的 USDOE Hanford 站点收集的各种沉积物通过实验测量的。使用超声波压电换能器在可变饱和沉积物中测量 P 波速度，并使用散热传感器测量基质吸力。样品的去饱和通过蒸发干燥发生。我们提出了一个模型，使用包括毛细应力和吸附应力的有效应力公式将 P 波速度的变化与土壤应力条件相关联。我们使用具有五个拟合参数的模型表明压缩波速度可以与基质吸力和围压相关。描述有效应力和 P 波速度之间关系的一组参数非常适合在 Hanford 地层样本上采集的数据。这里提出的结果表明地震方法在可变饱和汉福德地层沉积物中建立低基质吸力和流动条件的效用，可用于现场规模评估环境修复工作的性能，例如土壤干燥和表面渗透屏障.