A comparison of GPR and other geophysical techniques for geotechnical site investigation in hong kong

摘要

We have conducted an integrated ground penetrating radar (GPR), resistivity imaging (RI), and geotechnical and sedimentological study along a 90 m long traverse located at a grassy platform above a fill slope in Hong Kong. GPR profiles show buried objects and subsurface layers, which might be crudely explained by the construction methodology of the fill slope construction. In spite of the sophisticated data processing techniques used in analyzing the data, the GPR method by itself did not contribute any significant or new geotechnical information on the subsurface layers at the site. A visual analysis of the radar signals and range, however, shows strong signal attenuation in areas of lower apparent resistivity, which are due to higher moisture content and finer particle sizes. The study shows that GPR signal attenuation pattern may provide a systematic method for recognizing zones of moisture buildup, which may become a valuable tool in the assessment of the stability of slopes and retaining structures.