The electrokinetic (EK) effect as the basis for a non-invasive ground investigation tool

O'Hara-Dhand, K.A., 2004. The electrokinetic (EK) effect as the basis for a non-invasive ground investigation tool. PhD, Nottingham Trent University.

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Abstract

This thesis presents research relating to the detection of acoustically generated electromagnetic (EM) waves by a novel dipole aerial system in two differing geological environments. Both field and laboratory studies were conducted that concentrated on the electromagnetic response due to a compressional wave crossing a seismically contrasting boundary. The field investigation results revealed clear electromagnetic responses from a depth down to 30 metres and an indication of responses from the water table and fracture zones. Correlation of the EM responses was demonstrated by comparison to other geotechnical measurements. A method has been devised to detect the water table using the variation in the measured amplitude of the dipole distribution of the electric field away from the shot point, eliminating the need for extensive seismic refraction surveying. Laboratory studies on a consolidated sandstone sample, representative of the geology of one of the field locations, demonstrated clear electromagnetic responses from a water saturated bedding plane flaw. Readings were also taken with the sample reversed with a clear correlation of the EK responses in both cases. The laboratory results were comparable to those obtained for the field investigations. The encouraging results of the laboratory investigations have pointed the way forward for further research, such as similar carefully controlled laboratory experiments with other geological samples such as clay and consolidated limestone. The results demonstrate that the Electrokinetic technique will provide another useful technique to existing geophysical methods such as seismic refraction, electromagnetics, resistivity, GPR, etc for shallow ground investigation.

Item Type:	Thesis
Creators:	O'Hara-Dhand, K.A.
Date:	2004
ISBN:	9781369312768
Identifiers:	Number Type PQ10182978 Other
Divisions:	Schools > School of Science and Technology
Record created by:	Linda Sullivan
Date Added:	26 Aug 2020 11:13
Last Modified:	08 Jun 2023 08:39
URI:	https://irep.ntu.ac.uk/id/eprint/40524

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