Detection of Density Changes in Soils with Impedance Spectroscopy

Abstract

Measurement of soil parameters, such as moisture, density and density change, can provide important information for evaluating the stability of earthwork structures and for structural health monitoring. To ensure the stability of flood protection dikes, erosion at the contact zones of different soil zones must be avoided. In this work we propose the use of impedance spectroscopy to measure changes in density and volume caused by contact erosion. Erosion leads generally to a volume decrease in the contact zones between soils with different grain sizes and, consequently, to cavities in the dike structure. For this purpose, a proctor mould was developed for emulating contact erosion and the realisation of impedance measurements. Experimental investigations show a correlation between volume change of the soils in the proctor mould and impedance value. For a volume change of soil in the range of approximately 1.5% to 5.3%, an impedance change arises in the range of 17.2% to 29.8%. With several investigations we proof, that it is possible to detect material transport by impedance spectroscopy.

Structural health monitoring of inland navigation structures and ports: a review on developments and challenges

“…Several attempts have been made to monitor the internal seepage in dikes by (i) measuring the electrical resistance between two points in the soil, 231 (ii) using GPR measurements, 232 (iii) performing passive seismic interferometry with geophones, 233 and (iv) collecting temperature measurements with distributed fiber sensors. 234,235 Clemens et al 236 proposed measuring density and volume changes due to the contact erosion in dikes using the impedance spectroscopy. The technique employs capacitive sensors for measuring the dielectric properties of the surrounding soil.…”

Impedance Spectroscopy and Its Application in Measurement and Sensor Technology

“…The measurement of soil parameters can provide important information about the stability of earthwork structures. In [8], C. Clemens et al propose the use of impedance spectroscopy to measure changes in density and volume caused by contact erosion. Experimental investigations show a correlation between the volume change of the soils and impedance values.…”

Impedance Spectroscopy Sensing Material Properties for Self-Tuning Ratio Control in Pharmaceutical Industry

“…The material used for making a tablet varies in its density and geometry as it transits a set of physical states: liquid, powder, granules, etc. When describing nonlinear transport phenomena such as anomalous diffusion of mixed materials, one must also account for memory effects, which are typically arising as a non-Brownian random walk motion Equation [10,11]. These are linked to density variations of non-Newtonian fluids, an initial state of material incipient properties in the pharmaceutical industry.…”