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Virginia and Louisiana

Network GPR Surveys in Virginia and Louisiana

Challenge

Fugro Roadware recently performed GPR surveys in Virginia and Louisiana. Both jurisdictions needed subsurface pavement construction information, but for different reasons.

The Virginia DOT required more accurate construction information for its pavement management system (PMS). Variances in recent load-bearing tests had raised questions about the existing data’s reliability. The Louisiana DOTD needed to make its case for federal funding to repair damage
caused by Hurricane Katrina.

Much of North America’s road network is decades old. Highways have been widened, connected and resurfaced repeatedly. Construction and repair records are often unavailable. Coring is one option. However, Ground Penetrating Radar (GPR) is a more cost-effective, non-destructive and
non-disruptive alternative.

What We Did

In both cases, Fugro:

  • Collected GPR data using standard ARAN vehicles 
  • Collected pavement data along with pavement management survey all with a single pass
  • Scanned through all engineered layers of pavement—up to 40 in. (1 m) deep
  • Sampled at rates of up to one scan per 20 in. (0.5 m) at 50 miles (80 km) per hour
  • Directed the requirement for and location of core samples
  • Provided detailed reports of layer thickness values within construction segments
  • Delivered the data in PMS-compatible formats for use with client systems

Results

Virginia was able to collect reliable data without heavy use of coring. Louisiana was able to obtain the science-based information it needed to
make its case for post-Katrina highway reconstruction funding.

“The road itself is a state highway authority’s single most valuable asset. GPR analysis is the best way to understand what that resource is really worth.” ~ Allan Venema, Project Manager

Technologies Used

Fugro’s GPR services leverage:

  • A North American fleet of 18 ARAN vehicles with experienced data collection teams
  • GSSI SIR30 GPR data collection systems capable of scanning 12 in.  (0.3 m) wide x 40 in. (1.0 m) deep, scanning every 10 in. (0.25 m) at highway speeds
  • Multi-channel GPR with three antennas measuring 900, 1600 and 3000 MHz frequencies
  • Fugro’s experience analysing, interpreting and reporting on GPR surveys worldwide

Similar Applications

Network level GPR-based pavement information is ideal when a highway
authority needs:

  • Pavement structure information to make informed decisions
  • Support to interpret other pavement measures, such as surface condition and deflection
  • Science-based evidence of deterioration caused by wear or an event 
  • To understand the residual value of its highway network
  • To reduce risk of unknown factors during maintenance and reconstruction

To see the entire case study, click here.

Copyright Fugro Roadware 2013.