Using Ground Penetrating Radar for Locating Utilities
Utility detection is a very vital phase of project planning since it helps identify the type and location of utilities underground so as to prevent damaging them and also posing danger to the workers on site. This is a step that every engineer, contractor and construction stakeholder needs to do carefully and meticulously. Thanks to technological advancement, Utility detection is now possible in a two-step process by use of radio detection and Ground Penetrating Radar (GPR).
Ground penetrating radar uses radio waves to effectively and non-destructively locate subsurface structures and objects. SurveyEng Ltd is a reputable company with services majorly applied in the area of geological surveys using GPR for detection and mapping.
Why use GPR for locating utilities?
There are various and diverse methods of locating buried utilities. One of the most common approaches is the energising of metal pipes and cables using electrical currents and then employing magnetic-field sensors to detect the flow of the current. But this is only efficient and applicable where the utility is metallic. In the event there is a break in the flow of current, or there is interference of any kind from external factors, then the method is rendered inefficient. GPR provides better alternative since the GPR systems generates its own energy and detects both metallic and non-metallic objects. GPR offers an effective and cost-friendly solution to the problem of utility location.
Methodology
GPR is usually deployed in two major ways. Commonly, the “locate and mark” is used where the utility is located and the spot is marked. The second and more effective way is to map the entire area in a way that will create subsurface images. The latter is applicable even in complex situations.
Instrumentation
Most GPR systems operate within the 100 to 500 M H z. Such systems are able to offer the best compromise between spatial resolution and depth of exploration. It is these frequencies that also dictate the size of the sensor that is best deployed on a cart. For precision and sensitivity, it is usually recommended that carts are made of non-metallic materials. There is usually an integrated display unit to give feedback from the detection process and guide the surveyors.
GPR significantly enhances the understanding of subsurface targets and obstacles without having to dig. This is a more efficient and time-saving methodology than traditional methods of geological survey.
