American Geophysical Union Become an AGU Member
Subscribe to AGU Journals		 AGU Home AGU Publications

Read Full Article (file size: 1436822 bytes)    Cited by

WATER RESOURCES RESEARCH, VOL. 44, W02432, doi:10.1029/2007WR006078, 2008

Simulation assessment of the direct-push permeameter for characterizing vertical variations in hydraulic conductivity

Gaisheng Liu

Kansas Geological Survey, University of Kansas, Lawrence, Kansas, USA


Geoffrey C. Bohling

Kansas Geological Survey, University of Kansas, Lawrence, Kansas, USA


James J. Butler Jr.

Kansas Geological Survey, University of Kansas, Lawrence, Kansas, USA


Abstract

The direct-push permeameter (DPP) is a tool for the in situ characterization of hydraulic conductivity (K) in shallow, unconsolidated formations. This device, which consists of a short screened section with a pair of pressure transducers near the screen, is advanced into the subsurface with direct-push technology. K is determined through a series of injection tests conducted between advancements. Recent field work by Butler et al. (2007) has shown that the DPP holds great potential for describing vertical variations in K at an unprecedented level of detail, accuracy and speed. In this paper, the fundamental efficacy of the DPP is evaluated through a series of numerical simulations. These simulations demonstrate that the DPP can provide accurate K information under conditions commonly faced in the field. A single DPP test provides an effective K for the domain immediately surrounding the interval between the injection screen and the most distant pressure transducer. Features that are thinner than that interval can be quantified by reducing the vertical distance between successive tests and analyzing the data from all tests simultaneously. A particular advantage of the DPP is that, unlike most other single borehole techniques, a low-K skin or a clogged screen has a minimal impact on the K estimate. In addition, the requirement that only steady-shape conditions be attained allows for a dramatic reduction in the time required for each injection test.

Received 31 March 2007; accepted 8 October 2007; published 22 February 2008.

Keywords: Direct-push permeameter; hydraulic conductivity; numerical simulation; site characterization; parameter estimation.

Index Terms: 1894 Hydrology: Instruments and techniques: modeling; 1829 Hydrology: Groundwater hydrology; 1828 Hydrology: Groundwater hydraulics; 1849 Hydrology: Numerical approximations and analysis.

Read Full Article (file size: 1436822 bytes)    Cited by

Citation: Liu, G., G. C. Bohling, and J. J. Butler Jr. (2008), Simulation assessment of the direct-push permeameter for characterizing vertical variations in hydraulic conductivity, Water Resour. Res., 44, W02432, doi:10.1029/2007WR006078.