1989 Volume 30 Issue 3 Pages 121-130
Two types of geotomography techniques, seismic tomography and resistivity tomography, were reviewed and experimentally applied to the foundation rock investigation at a dam site. The target area was a vertical section defined by test adit and boreholes excavated at the site. Previous drilling investigations revealed the existence of a weathered layer and a complex series of faults within the section.
The distribution of P wave velocity within the section was reconstructed by seismic tomography. The weathered layer and faults showed up as low velocity zones. The image reconstructed from resistivity tomography showed the weathered layer and faults as high and low resistivity zones, respectively. In addition, it was found that the condition of rock could be appropriately estimated by interpreting the results of both seismic and resistivity tomography together.
In the future, it is expected that geotomography will provide useful information for elucidating complex geological structures.
