The hydraulic conductivity of sediments: A pore size perspective

Abstract
This article presents an analysis of previously published hydraulic conductivity data for a wide range of sediments. All soils exhibit a prevalent power trend between the hydraulic conductivity and void ratio. Data trends span 12 orders of magnitude in hydraulic conductivity and collapse onto a single narrow trend when the hydraulic conductivity data are plotted versus the mean pore size, estimated using void ratio and specific surface area measurements. The sensitivity of hydraulic conductivity to changes in the void ratio is higher than the theoretical value due to two concurrent phenomena: 1) percolating large pores are responsible for most of the flow, and 2) the larger pores close first during compaction. The prediction of hydraulic conductivity based on macroscale index parameters in this and similar previous studies has reached an asymptote in the range of kmeas/5≤kpredict≤5kmeas. The remaining uncertainty underscores the important role of underlying sediment characteristics such as pore size distribution, shape, and connectivity that are not measured with index properties. Furthermore, the anisotropy in hydraulic conductivity cannot be recovered from scalar parameters such as index properties. Overall, results highlight the robustness of the physics inspired data scrutiny based Hagen–Poiseuille and Kozeny-Carman analyses.

Citation
Ren XW, Santamarina JC (2018) The hydraulic conductivity of sediments: A pore size perspective. Engineering Geology 233: 48–54. Available: http://dx.doi.org/10.1016/j.enggeo.2017.11.022.

Acknowledgements
Support for this research was provided by the Fundamental Research Funds for the Central Universities, China University of Geosciences-Wuhan (No. CUG160701, CUG160813), the National Natural Science Foundation of China (51708526), the USA Department of Energy, and KAUST's Endowment. The authors are grateful to Man Chap Fu Jeff and G.E. Abelskamp.

Publisher
Elsevier BV

Journal
Engineering Geology

DOI
10.1016/j.enggeo.2017.11.022

Additional Links
http://www.sciencedirect.com/science/article/pii/S0013795217304866

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