Time Domain Reflectometry (TDR) is commonly known as "cable radar" and was initially used by the cable TV and communications industries to find problems in coaxial cables. This time-tested technology was adapted by GCI's Kevin O'Connor to monitor movement of foundations, roadways and slopes as well as changes in groundwater conditions and soil moisture. Coaxial cables and probes are used for remote automated surveillance of large volumes of soil or rock.

geo tdr services

Practical risk assessment

Settlement, subsidence, lateral creep and slope failure problems are not always amenable to simple analysis or recommendations based on empirical calculations. Site-specific monitoring over extended time periods can be the only valid approach for assessment of changing conditions and risk.

Cost effective

The use of GeoTDR instrumentation is a cost-effective solution to remotely assess potential problems in critical project areas where traditional observation techniques are not a viable option. The remote automated monitoring combined with web-based data display, management and email notification of alarm conditions allows clients to proactively respond to critical situations.

GeoTDR applications

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Clients in the following industries have benefited from remote monitoring of subsidence and slope stability, utilizing GeoTDR monitoring systems to manage risk and liability, as well as, to gain enhanced knowledge of ground movement mechanisms by virtue of continuous monitoring:

GeoTDR services

GCI provides design, installation and monitoring of early warning GeoTDR systems for critical structures near unstable slopes or over abandoned mines. Services include:

To learn more about GeoTDR and how this technology can manage risk and provide an early warning system on your project contact GCI's GeoTDR department at 614.895.1400.

Kevin M. O'Connor, P.E. koconnor@gci2000.com

For technical information about the development and applications of GeoTDR, the book authored by GCI's Kevin O'Connor can be purchased at the link below.


GeoMeasurements by Pulsing TDR Cables and Probes examines Time Domain Reflectometry (TDR) research and provides information on its use as a robust, reliable, and economical production tool.

Common uses for TDR technology include telecommunications and power industries but the text examines applications such as measurement of moisture of unsaturated soils; detection of fluids for leak and pollution; measurement of water levels for hydrological purposes; measurement of water pressures beneath dams; and deformation and stability monitoring of mines, slopes, and structures.