Locating and recording utility equipment can often be more difficult than initially expected. Drawings become outdated, historical records are misplaced, and the shift from hand-drawn to computer-based plans has further complicated the archives.
However, the adoption of GPR (Ground Penetrating Radar) can help utilities confirm the location of underground utilities and contribute to proactive work planning by identifying and avoiding hazards where possible. Below is more information on this method and why GPR detection is used.
What is GPR?
GPR is used in many areas to observe man-made and natural features. GPR detects metallic and non-metallic pipes, power lines, conduits, water lines, rebar and post-tensioning cables within concrete.
GPR waves are equal to those of a cell phone or wifi network, while x-rays require a 50-foot clearance before being used for safety reasons. In general, GPR is the most cost-effective option and the fastest method of testing concrete.
The principle of using radio waves to determine internal ground structures has been known for a long time. Among the first works in this field, the use of radio echo sounders to determine the thickness of ice layers in Antarctica and the Arctic and to measure the thickness of glaciers is undoubtedly the greatest success. GPR detection in non-glacial areas was initiated in the early 1970s. The first achievements focused on work on permafrost soils.
What is the penetration depth of GPR?
Although the physical principles are well known, most people using GPR for the first time are not aware that there are fundamental physical limitations. Many people believe that GPR penetration is limited by the instruments. This is true in a way, but the depth of penetration depends primarily on the material itself and any improvement in instrumentation will not overcome the fundamental physical limitations.
The advantages of underground detection by GPR
GPR does not wake up the neighbors
Excavation work has another set of major disadvantages such as creating pollution and noise. This can lead to loss of property value and legal action. On the other hand, subsurface detection by GPR does not cause such problems because the radar is silent, which means that it does not disturb people or the ground. This is ideal for urban areas where the comfort of the surrounding people is the key to successful development.
Avoiding costly mistakes
It can be tempting to rush the demolition process when your schedule is compromised. However, this can have serious consequences, as you risk cutting through a wall or concrete. Repairing a severed duct costs at least $1,000. Keep in mind that potential safety hazards, additional delays and repairs can negatively impact your company’s reputation and project schedule. GPR can detect underground utilities, steel and voids without disturbing structures or soil.
GPR is versatile
Underground detection by GPR is carried out on large surfaces. Contact the companies that are looking for professionals who are comfortable in large areas. These are the same people who can call you to search for mines in more remote areas. With the growth of residential areas, these sites represent a real market to conquer. In the building sector too, risks can be avoided by locating possible tunnels.
Legal requirement
The use of GPR must meet a legal requirement. As a detector of metallic and non-metallic materials, this device can be misused by non-professional researchers. In order to preserve the heritage, there is a code that governs the discovery and exploration of witnesses of the past. Knowledge of this code is a simple formality for those who purchase GPR.
Security
If a mistake is made, if the equipment hits an unexpected object, it can have catastrophic consequences. In addition to damage to the equipment and the site, improper handling can result in injury and loss of life. Tension rods and cables can break and cause danger to anyone in the vicinity. Therefore, it is essential that everyone working has a clear idea of the nature of the work.
Efficient turnaround times
Planning the project schedule and updating it based on the many influencing factors such as weather, mechanical breakdowns, contractor attendance and unexpected changes can affect profitability. GPR detection before the launch of a project prevents potential incidents during excavation. Avoiding cutting or digging unseen elements ensures schedule compliance and avoids unnecessary repair costs and safety issues.
Conclusion
GPR can be used in many other applications. Assessing concrete structures for rebar, post-tensioning cables, and embedded conduits before cutting them for repair or renovation is a popular use of this technology. GPR is also widely used to locate buried utilities such as cables, pipelines, concrete structures and plastic objects under the ground or in concrete. Please contact us if you would like to learn more about our GPR detection services.