Concrete Imaging Ground Penetrating Radar used at Lake Okeechobee boat locks

South Florida Water Management District – Lake Okeechobee, FL – Recently GHD used its 2.3GHz Concrete Imaging Ground Penetrating Radar (CIGPR) system to perform surveys at three boat lock sites. The Army Corp of Engineers specified this scope of investigation to avoid damage to the structures during the installation process which included coring into the concrete to install support fasteners.

CIGPR offers a detailed view of “what’s within.” This process yields real time results which are not possible with traditional radiographic (x-ray) methods. As important, using GPR is safe and does not require the evacuation of the public and other personnel.

Concrete Imaging Ground Penetrating Radar used at Palm Beach International Airport – New Body Scanner and X-Ray Equipment

Palm Beach International Airport – West Palm Beach, FL – Recently GHD used its 2.3GHz Concrete Imaging Ground Penetrating Radar (CIGPR) system to perform surveys at all concourses. The Airport Authority specified this scope of investigation to avoid damage to the electrical and communication systems within the concrete floor decking prior to core drilling access points for the new equipment installation.

CIGPR offered a detailed view of “what’s within.” This process yielded real time results which were not possible with traditional radiographic (x-ray) methods due to access limitations. As important, using GPR is safe and does not require the evacuation of the public and other personnel.

The survey not only yielded information for electrical and communications avoidance but also delineated main structural support beams beneath the concrete deck. These discoveries aided in the redesign for observation rooms also constructed.

Concrete Imaging Ground Penetrating Radar used at the Citrus Bowl

The Citrus Bowl – Orlando, Fl – LED Ribbon Boards (score boards) were installed as part of a recent renovation.  This type of score board can display amazing graphics, real-time content and statistics.

Prior to installation, it was critical that any utilities and supporting structures be identified.  Ground Hound Detection Services (GHD) used its 2.3GHz Concrete Imaging Ground Penetrating Radar (CIGPR) system to scan over 1200sqft of concrete fascia.  Engineers of the facility were looking for assurance that the integrity of the structure would not be compromised during the installation process which included coring into the concrete to install support fasteners. The discoveries allowed the contractor to make adjustments and avoid structural impact.

CIGPR offers a detailed view of “what’s within.”  This process yields real time results which are not possible with traditional radiographic (x-ray) methods.  As important, using GPR is safe and does not require the evacuation of the public and other personnel.

Phase One Applications to Accurately Locate Underground Storage Tanks

Phase One Surveys are often performed (EPA CERCLA) by Environmental Engineering Consultants to study the historical usage of a property.   Part of the process includes an Underground Storage Tank/Structure (UST’s) investigation.  Fuel stations or vehicle repair facilities are likely to have (or have had) buried UST’s. The Consultant must determine whether the UST’s have been recorded, removed or are still in place.  A geophysical subsurface survey can determine the presence of objects or structures if they in fact exist.

To do this, a site will be divided into logistical/manageable sections.  Orthogonal scans using a combination of magnetic detection and Ground Penetrating Radar (GPR) equipment are used in an effort to identify/delineate any anomalies within the subsurface. A magnetometer is good reconnaissance tool enabling quick coverage and very accurate detection of sizable metallic objects. As metallic objects are detected they can be fairly accurately confirmed as small linear objects (pipes & cables) or larger regularly- or irregularly-configured objects. Many small metallic objects can be quickly eliminated from the investigation as part of normal utilities and operating systems typical for a site given its historical usage. The remaining discoveries can be investigated and scrutinized in more detail with GPR.  

GPR has the advantage of detecting non metallic as well as metallic objects within the subsurface. In fact, GPR can, in many cases, detect areas of disturbed soils and delineate the areas whereby differing soils types exist throughout a site.  The radar pulses radio waves within the subsurface. These waves continue to propagate downward until they interface with objects that result in reflection back to the GPR receiver. The amount and rate at which these reflected waves are measured indicate the size, shape and distance of where these reflections (events) occurred. This energy is affected by the dielectric properties of everything they contact, including the subsurface geologies (soils). Waves propagating without contact with a highly reflective object will eventually fade out when their energy is exhausted.  

Below is a typical event sequence of a subsurface UST investigation. Specific locations for soil sampling bores were marked on the ground surface by the client (white paint). GHD performed the survey and detected/delineated three anomalous events consistent with buried UST’s (orange paint).  Excavation of the area confirms GHD’s findings.   The last photo is of the GPR data profile for the discoveries.

Vacuum Excavation

A non-destructive method for obtaining detailed information on underground utilities and objects such as: size, configuration, condition & vertical elevation. The procedure begins with cutting a small hole into the ground surface. Then a combination of compressed air and high-pressure vacuum are used together to extract the spoil and safely expose the target. After information is collected, a full restoration is completed. A summary of our findings is produced and provided in a client specified format. The vacuum excavation technique is an industry standard and an efficient way to quickly obtain accurate information with low risk of damaging underground assets.

Subsurface Utility Engineering

Since its inception, GHD has been involved in providing Subsurface Utility Engineering services (SUE). The SUE process includes designations for underground utilities as defined by the FHWA for SUE services. The process also conforms to the American Society of Civil Engineers (ASCE) Standard CI/ASCE 38-02 for the collection and depiction of existing subsurface utility data. SUE is an engineering process utilizing state-of-the-art technology to accurately identify, characterize and map underground utilities prior to excavation and design of new structures or the installation of new underground assets. GHD is NOT an engineering firm and therefore not a potential “competitor.” Consider that when choosing a sub consultant for your underground utility needs & future projects.

 

GHD provides all Levels of SUE:

Quality Level D
The most basic level of information is obtained, requiring a search of all reasonably accessible utility databases.

Quality Level C
This level requires a visual inventory to ascertain the general accuracy of the plans obtained during the Level D phase. The visual inventory may include, but is not limited to, above-ground infrastructure associated with utilities such as manholes, valve boxes, utility poles, etc.

Quality Level B
The level in which geophysical methods are employed to “designate” the existence and horizontal location of utilities within a project area.

Quality Level A
Vacuum excavation is employed to safely expose utilities, providing an exact three-dimensional location and positive identification of the utility. This level provides for the visual verification and measurement of precise horizontal and vertical positions of utilities.

Concrete Imaging Ground Penetrating Radar

We now offer High Resolution Ground Penetrating Radar (GPR) to our list of services. The latest in high frequency GPR, it provides an alternative to construction-grade X-ray without the associated negative effects. Concrete Imaging GPR has forensic applications to determine concrete thickness as well as delineating steel reinforcement bars, post tension, electrical and communication raceways within concrete decking. This new technology has proven to be an economical solution for remodeling projects and environments where X-ray is not conducive. In fact, Palm Beach International Airport’s damage avoidance procedures have included  Concrete Imaging GPR as a protocol prior to core drilling. For more information on our services, visit: GroundHound.com

Ground Penetrating Radar

GPR is very useful for locating and delineating underground utilities, especially those of nonmetallic material types. By systematically scanning the target area, the linear paths and outlines of underground objects and features can be seen and recorded. Additionally, GPR can be deployed for “green space” purposes along a proposed trench line. This allows the designer and/or excavator a route which minimizes utility contact in an otherwise congested pathway. GHD has years of success with GPR locating: PVC, Poly pipe, RCP (Reinforced Concrete Pipe), ACP (Asbestos Concrete Pipe), VCP (Vitrified Clay Pipe), Trench lines, delineation of contaminated areas, UST’s (Underground Storage Tanks) and structures.

About Ground Hound Detection Services

Since its inception in 1994, Ground Hound Detection Services, Inc. (GHD) has been providing utility locating and related survey services to design professionals, public and private property owners, utility owners, contractors, municipalities, educational and institutional facilities. GHD has been regarded as providing an “invaluable service” by those requiring comprehensive information of below ground utilities and structures. During the design phase of a project, our services are utilized to provide: utility coordination for both public and private, physical location and verification of existing utilities. GHD then provides a comprehensive utility site plan of its discoveries. Prior to excavation GHD conducts subsurface investigative surveys to determine the presence of conflicting utilities that otherwise would be impacted during the course of excavation. Identifying utilities prior to excavation assures safety for excavating personnel as well as maintaining uninterrupted service of vital utility systems. The quality, experience and professionalism in which GHD provides are unparalleled within our industry.

We pride ourselves in our thorough understanding of utility systems and the theory of geophysical detection equipment. As a result, GHD transcends our client’s expectations. Since our inception, GHD has never deviated from what we do best, “provide complete and accurate subsurface investigations” using the latest advancements in technology. GHD is NOT an engineering firm and therefore not a potential “competitor”. Consider that when choosing a sub consultant for your underground utility needs & future projects.