《Journal of Geotechnical and Geoenvironmental Engineering》杂志刊登

“一种采用时域反射计的土体密度和含水量测量的新方法”

作者：Sochan Jung; Vincent P. Drnevich; and Majdi R. Abou Najm

刊物：《Journal of Geotechnical and Geoenvironmental Engineering》，2013年5月，139卷第5期，659–670页

关键词：电磁学；压实；校准方程；时域反射计；含水量；干密度

摘要：本文给出了一种确定不同击实功下土体含水量和密度的新方法。并介绍了一个新的校准方程，该方程利用了电磁波首次通过土壤试样的电压降，波传播停止后的最终电压水平，以及由水密度标准化后的土的干密度。新的校准方程考虑了干密度的直接计算。随后将干密度的值用于标准化的表观介电常数方程来确定含水量。通过对不同种类的土（包括粗粒土）进行的大量室内试验，结果表明本文提出的方法能够适用于不同水平的击实功。采用室内击实试验确定特定土体的模型系数，该方法与在不同地点的岩土工程土方施工中进行的原位试验同样有效。该研究的结果表明这种新的校准关系与击实功和时域反射计（TDR）试验中探针构造的影响呈相对独立。该方法改进了单步时域反射计法。

New Methodology for Density and Water Content by Time Domain Reflectometry

Authors: Sochan Jung; Vincent P. Drnevich; and Majdi R. Abou Najm

Journal: Journal of Geotechnical and Geoenvironmental Engineering, Volume 139, Issue 5 (May 2013), 659–670

Key words: Electromagnetic, Compaction, Calibration equations, TDR, Water content, Dry density

Abstract: This paper provides a new methodology for determining soil water content and density under different compaction energies. A new calibration equation was introduced making use of the voltage drop associated with the first passage of the electromagnetic wave through the soil specimen, the final voltage level after wave propagation ceases, and dry density normalized by the density of water. The new calibration equation allows for the direct calculation of dry density. Values of dry density are then used in the normalized apparent dielectric constant equation to determine the water content. Results of numerous laboratory tests on a wide variety of soils (including coarse-grained soils) showed that the proposed method accommodates different levels of compaction energy. The method also was validated with different field tests at sites commonly used in geotechnical earthwork construction, using soil-specific model coefficients determined from laboratory compaction tests. The results of this study indicate that the new calibration relationships appear relatively independent of the effects of compaction energy and of probe configuration in time domain reflectometry (TDR) testing. The proposed method presents an improvement to the one-step TDR method.

原文链接：http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000783