Thursday, September 25, 2014

Seeing the Unseen: Ground-Penetrating Radar Helps Locate Underground Utilities

One of the trickiest parts of any freeway project is utility relocation. Before major construction begins, underground utilities must be mapped and, in some cases, relocated. Often, potholing is used to confirm utility location. (Potholing is the practice of exposing an underground utility to identify its positive horizontal and vertical location.

On the Empire Project in Burbank, Caltrans used a relatively new technology: ground-penetrating radar (GPR). GPR is a nondestructive way to detect the depth and location of utilities and to create a detailed 3D image of what lies underground. This can help save money because accurately identifying utility location can prevent costly change orders. And there's no digging!

To see a GPR crew in action on the Empire Project and learn more about this technology, check out the video below.