Infrastructure Management Using GPR

According to the Infrastructure Report Card prepared by ASCE, “America’s roads are often crowded, frequently in poor condition, chronically underfunded, and are becoming more dangerous. One out of every five miles of highway pavement is in poor condition and our roads have a significant and increasing backlog of rehabilitation needs”. With over four million miles of roads crisscrossing the United States, roads are among the most visible and familiar forms of infrastructure. In 2016, U.S. roads carried people and goods over three trillion miles and are an essential component of the national GDP and employment growth.

Proper infrastructure condition and performance assessment of existing infrastructure will be central to cost-effective long term asset management at the local and state level. With deferred road and bridge maintenance over all these years, a significant portion of initial spending will have to be allocated to assessing and restoring existing infrastructure compared to that for added new capacity. Cost-effective asset management is a significant balancing act for federal, state and local infrastructure agencies.

BHATE Geosciences is leading the process and is at the forefront of new technology for infrastructure assessment and asset management. The engineering assessment must include three broad dimensions of effectiveness, reliability, and cost. The first steps in the performance assessment process are directed at developing a broad inventory of the infrastructure system using advanced methods of assessing road and bridge performance. Our latest technology includes utilization of the ‘air-launched’ GPR system. BHATE was among the first in the southeast to utilize ground penetrating radar (GPR).

BHATE has multiple teams solely dedicated to utilizing this technology and has cost-effectively provided these services on some of the largest projects in the region. According to Jack Morrisroe, our geophysicist specializing in air-launched GPR technology, “The importance of having personnel dedicated to utilizing GPR cannot be stressed enough. Correctly interpreting GPR data is key to getting accurate and repeatable results from a geophysical survey.”

The following comment from a client exemplifies the value created by this new technology and highly experienced BHATE personnel,  “BHATE Geosciences recently conducted a pavement evaluation for us. We were impressed with the data delivered to us and with the speed at which the data was collected. The technology enabled us to understand the nature of the pavement in a way that traditional coring would not have been able to and we recognize opportunities for routine implementation of GPR technology in the future.” – Escambia County, Florida.

BHATE Geosciences utilizes advanced ground penetrating technology that is now able to operate at faster speeds and store more data with increased data clarity. With antennas suspended 20 inches above the pavement surface, Air-launched GPR is capable of collecting information about pavement layers and subsurface anomalies at traffic speeds as high as 60 miles per hour. This also significantly improves the safety aspect of the fieldwork, which in the past required blocking lanes with personnel working with manual equipment on heavily-traveled roads causing hazardous conditions.

Our latest technology and GPR equipment can provide roadway information that can be used for:

  • Routine maintenance such as overlays
  • QA/QC for new pavements
  • Gathering data on unrecorded maintenance prior to milling
  • Increased accuracy of back-calculation of FWD data
  • Determination of pavement deterioration including stripping and moisture-filled de-bonding
  • Understanding pavement thickness changes across the profile of a lane

Bridge Deck Assessment: Air-launched GPR is not only used for pavement assessments; bridge deck evaluations can be conducted with the technology as well.  According to ASCE’s 2017 Infrastructure Report Card, 40% of the bridges in the U.S. are 50 years or older, 9.1% of which are structurally deficient.

With estimated rehabilitation costs in the billions, efficient bridge evaluations and strategic bridge repairs are necessary to maximize rehabilitation efforts.  The air-launched GPR evaluations can assist bridge engineers with bridge deck assessments with little to no disruption to other road users.  The evaluations conducted with the technology can identify:

  • Bridge Deck Delamination
  • Rebar corrosion
  • Trapped moisture content
  • Deterioration percentage calculations

Aging Utility Infrastructure: Many cities with older underground utilities are seeing failures and subsurface erosion causing loss of ground support, often resulting in dangerous collapses and sinkholes.  Once an underground utility fails, there is a high potential for the soil overburden to gradually erode and wash away into the pipe.  Over time, the washout cavity will reach the surface causing a collapse and a serious life safety hazard and a significant disruption to both road users and a big dent in the road maintenance budgets.

It is becoming more common to see a news article about a road collapse in congested urban areas. BHATE can use air-launched GPR to cost-effectively identify these subsurface anomalies. The information gathered can be used to identify where subsurface voiding is potentially occurring, resulting in improved safety by addressing, repairing and preventing potential serious future problems in a timely and cost-effective manner.

BHATE has been in discussions with ALDOT, MDOT, GDOT and other DOT’s and various cities and counties to routinely implement air-launched GPR technology to perform routine periodic deterioration monitoring throughout a structure’s life.  Knowing where the active deterioration is occurring allows the engineers and owners to make better decisions in addressing the causes of deterioration, planning, and prevention of future failures.

While there will never be enough funding to solve all our infrastructure needs, at BHATE Geosciences we are committed to developing cost-effective solutions based on sound engineering principals and the latest technology. We all share a role in renewing the nation’s infrastructure and solving these problems will take collective action. Every day we continue to delay investing in our nation’s infrastructure, we escalate our costs and risk our safety and security.