Application of Ground penetrating radar.

1. SEMINAR ON
APPLICATION OF GPR
GUIDED BY:
Prof; . A.BALASUBRAMANIAN
DOS in Earth Science
MANASAGANGOTHRI
PRESENTED BY:
VINAY . C
M . Sc Geology
DOS in Earth Science

2.  Introduction
 Application of GPR
 ENVIRONMENTAL & ARCHAEOLOGICAL SURVEYS
 Oil and Gases
 CIVIL SURVEYS
 Advantages of GPR
 Disadvantages of GPR

3. Introduction
GPR is a geophysical method that uses radar
pulses to image the subsurface. This
nondestructive method uses electromagnetic
radiation in the microwave band of the radio
spectrum , and detects the reflected signals from
subsurface structure.
GPR can have application in a variety of media,
including rocks, soils, ice, fresh water, pavements
and structures. In the right condition ,
practitioners can use GPR to detect subsurface
objects, changes in material properties, and voids
and cracks.

4. APPLICATIONS
ENVIRONMENTAL & ARCHAEOLOGICAL SURVEYS
 mapping extent of contaminant plumes
 determining direction of contaminant migration
 locating buried storage tanks
 locating buried artifacts, ruins or treasures
 delineating boundaries of ancient cemeteries and locating burial plots
 Mapping gravel and sand deposits, determining depth and quantifying
volumes
 Glacial ice thicknesses - in cold ice bedrock-ice contact can be
mapped.
 Finding rebar or culverts during highway construction.
 Finding caves or sinkholes.

5. Oil & Gas:
Location of pipelines, utility lines, water and sewer pipes for gas
/ oil facility surveys
Assessing depth of sediment cover over pipeline river crossings
and rights of way
Determining depth to bedrock for proposed pipeline rights of way
Aerial reconnaissance
Survey depths up to 4 meters or more (depending on soil conditions -
see chart)
GPR can be tied to a GPS to yield precise locations
3-D software allows results to be obtained with x, y and z coordinates

6. CIVIL SURVEYS
 Accurate location of in-slab:
structural steel (re-bar)
stress cables
 electrical and communication conduits - including
PVC, fiber optics, telephone wiring and other non-
ferrous materials
water and sewer pipes
 It is essential to avoid hitting these features when
coring or drilling through a concrete slab during
construction renovations.

7. Advantages of GPR
As opposed to other locating techniques that are capable of detecting only
metallic or conductive utilities and underground targets, GPR can locate
and characterize both metallic and non-metallic subsurface features. It is
completely nonintrusive, nondestructive and safe. GPR can be thought of
as a Subsurface Imaging System, similar to sonar used for underwater
applications. With GPR, surface conditions are not a major factor. Targets
can be "seen" beneath reinforced concrete, asphalt, gravel, and most other
common surfaces.
• High-resolution data in certain cases.
• Non-destructive and quiet.
• Requires only one or two people for field work.
• Fast and economic.
• Wide spatial coverage may be obtained, can
be towed by a truck.

8. Disadvantages of GPR
 Equipment is expensive.
 Limited penetration depths.
 Can be used in only specific sediment-bedrock
terrains.
 Requires trained people for data collection and
interpretation.
 Post-processing of data requires sophisticated
computer software
 Information about dialectric properties must be
known in order to convert to wave return times to
depths.

9. References
GG 450,Lecture 19 ,February 26, 2006,Ground Penetrating
Radar
http://www.joeinfo.com/gpr/antenna.MOV
http://www.joeinfo.com/gpr/overview.MOV