RESISTIVITY SOUNDING IN ENGINEERING INVESTIGATIONS WITH THE OFFSET WENNER TECHNIQUE

This paper reviews the principles of the offset sounding technique and demonstrates how high quality Wenner apparent resistivity curves can be easily obtained in engineering site investigations. The significant advantages of the technique include a decrease in necessary manpower and an accompanying increase in productivity. Electrode spacing errors are also eliminated. The case of operation of the commercial systems now available has led to increasing use of the system in shallow hydrogeological and civil engineering investigations and in the extractive mineral industries. An example of its use in determining the thickness of clay overlying a dolerite dyke for a proposed quarry extension is described.