Application of Traveltime Tomography Methods to Imaging a Dam Site

In underground rock mass engineering, the crosshole tomography can be used as a relatively economical and efficient tool to provide the unique subsurface information that can not easily be obtained by other techniques. Compared to X-ray CT, the crosshole wave transmission tomography is more complicated due to the inherent properties of limited view and ray bending. But the successful applications have been made through continuing efforts to date. These applications have been extensively reported in the literature for mineral/oil exploration, site investigation for nuclear waste disposal, and mining safety planning, etc.[l-4]