GPR

Ground Penetrating Radar can also be utilized to inspect concrete up to 18" thick for pipes, rebar, and conduit. Please click HERE to learn more, or contact an Enviroprobe representative at (800) 596-7472 for project specific questions.

The GPR method can be used for very rapid, high resolution mapping of the shallow subsurface to:

• Locate metallic and nonmetallic pipes and utility cables
• Delineate underground storage tanks (metallic and nonmetallic)
• Map rebar in concrete structure 
• Map landfill boundaries 
• Delineate pits and trenches containing metallic and nonmetallic debris 
• Delineate leach fields and industrial cribs 
• Delineate previously excavated and backfilled areas 
• Map shallow groundwater tables 
• Map shallow soil stratigraphy 
• Map shallow bedrock topography 
• Map subsurface voids and cavities 
• Characterize archaeological sites

GPR profile crossing 3 USTs and a pipe

 

GPR profile along an UST

 

An underground storage tank (UST) and associated pipes marked onsite

Ground-penetrating radar (GPR) is a high-frequency electromagnetic method that can be applied to a number of engineering and environmental problems.  A GPR system radiates short pulses of high-frequency EM energy into the ground from a transmitting antenna. This EM wave propagates into the ground at a velocity that is related to the electrical properties of subsurface materials (specifically, the materials relative dielectric permittivity). When this wave encounters the interface of two materials having different dielectric properties (i.e., utility and surrounding soils), a portion of the energy is reflected back to the surface, where it is detected by a receiver antenna and transmitted to a control unit for processing and display. 

Depth penetration is a function of antenna frequency and the electrical conductivity of the soils in the survey area. Lower frequency antennas achieve greater depth penetration than higher frequency antennas, but have poorer spatial resolution.  Enviroprobe owns and operates Ground Penetrating Radar (GPR) units equipped with 1000mhz, 500mhz, or 250mhz antennas. 

 

This inGPR profile showing underground slopes indicating past excavation activities

 

GPR depth slices at a ceremony showing burials at different depths