PROJECT ENGINEERING SUPPORT
Wind turbine farms are becoming commonly used nowadays in the energy sector. They have the ability to produce GREEN energy by using the renewable energy source that is provided by nature. These giant energy producers are essentially installed and assembled on site. That means the parts are being transported with heavy duty semi-trucks on roadways. Each transport would introduce great load to the pavement of roadways that could cause permanent damage.
On the other hand, this transportation project would require having comprehensive as built information of the affected roadways making sure that the layer thickness of asphalt pavement is adequate. Transportation engineering must also need to know if there is any fault in the subgrade or shallow ground void existing within the transportation route that could result in compromising the safety of transport.
There is a quick and reliable way to conduct a layer thickness assessment non-destructively by utilizing an Air Launched Ground Penetrating Radar (also known as GPR) system. The data acquisition does not require any road closures or special permit from DOT. The GPR data is collected with a survey vehicle that can maintain up to 60mph. The speed results in a lower data sampling rate both in a horizontal and vertical direction.
In order to increase the accuracy of thickness readings, multiple core samples need to be collected in different locations of the roadways. Collected raw GPR data must be post-processed offsite to create an appropriate cross section (radargram) for the analysis. The following images are indicating the result of this process. A color coded and georeferenced polygon is indicating the variation of FIRST layer thickness of investigated roadway. That information can and will also be translated and exported into a commonly used ASCII file. Exported point spacing is equidistant and containing location (Northing/Easting/Relative Elevation) info as well as layer thickness and additional information of current subbase condition, if it is applicable.
OmniVueNDT’s road scanning department is dedicated to assisting in such projects and providing engineering support for safe work practices.
