| Project Background |
| Governmental agencies were designing a
flood control project for a large creek. The project
consisted of dredging in several areas of the creek,
raising questions regarding the locations and depths of
potential utility crossings. The continually-changing
silt levels within the creek bed rendered existing
utility maps useless. |
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| Geo-Graf Investigation |
| Geo-Graf utilized 4 different nonintrusive
geophysical delineation techniques, including Ground
Penetrating Radar (GPR). Our GPR antennae were floated
down the creek, generating continuous profiles of the
creek bed and subsurface. Utilities extending beneath the
creek bed were located and field-marked. |
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| GPR Data Profile |
| Please Wait as
the image below loads. It is actual radar data from the
underwater utility project collected by Geo-Graf
engineers utilizing a 120 MHz GPR antenna. |
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| Above: A GPR data profile over the
investigated creek. Shown are two underwater utility
crossings: a gas main and telephone duct. Both utility
systems were located beneath several inches of creek bed
silt. 120 MHz GPR antenna system. |
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