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Safe Excavation
The Need
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Excavating with a backhoe or similar equipment
has the potential risk of hitting an underground utility which could cause serious
injuries and expensive damages. Contractors usually rely on utility companies or other
professional services to mark the area where cables or pipes are buried. But without being
able to know the depth and exact position of the line.
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The Occupational Safety and Health
Administration - OSHA - estimated that the fatality rate was at 50.8 deaths per 100,000
workers per year from 1984 to 1988. The National Institute of Occupational Safety and
Health estimated that at least 127 persons were killed as a result of all
excavation-related accidents (Huang et al. 1996). |
The Technology
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An electronic device that provides a real-time
warning of the utility lines immediately ahead of the digging tool and provides an easily
interpreted, real-time computer readout of the depth, location, and size buried metallic
objects. Developed by Dr. Leonhard E. Bernold, it consists of an active metal detector
search coil; a signal processing (control) unit; and a PC computer equipped with an
analog-to-digital converter interface. The active
metal detector generates a magnetic field. Its impact on any metal object in its detection
range is picked up by the control unit. The data is converted from analog to digital at a
high sampling rate and transmitted to the computer. The computer receives real-time data
about magnetic changes in the detector vicinity, graphs it on the screen, sounds a signal,
and stores it in a file for future analysis. |
The Benefits
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The device helps in the detection and location
of hidden underground cables, gas pipes, toxic waste drums and even bombs. It is a
portable system that can be attached to backhoes, trenchers and other digging equipment. |
Status
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The system is ready for implementation but the
designer is looking for investors and a production contract. An actual job site
application of the system has not yet occurred. An enhanced device is being developed that
can detect plastic-coated utility cables and fiber-optic telephone lines. |
Barriers
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The cost of the system is the current major
barrier because of the lack of a production contract. The device will not detect plastic
pipes or objects that do not have a metallic component. The detection depth or range of
the system is limited by the capacity of the active metal detector. |
Points of Contact
Leonhard Bernold, Associate Professor of Civil Engineering,
North Carolina State University, Raleigh, NC. (919) 515-3677
References
- Huang, X., Bernd, D., and Bernold, L.E. "Equipment
Mounted Buried Utility Detection System"
- Huang, X., Bernd, D., and Bernold, L.E. ‘Innovative
Technology Development for Safe Excavation’ Journal of Construction Engineering and
Management, Vol. 122, No. 1, March, 1996.
- ‘New N.C. State Device Uncovers Hidden Dangers
Underground’ North Carolina State University News Release, August 16, 1995.
Disclaimer Statement
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Neither the Construction
Industry Institute nor Purdue University in any way endorses this
technology or represents
that the information presented can be relied upon without further investigation. |
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