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Services
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A wide range of
services offered
Geophysics GPR International offers a wide
range of applied geophysical services to the civil engineering
community. GPR counts on a multidisciplinary team capable of performing
land, marine and airborne geophysics. GPR offers the following
services:
- The Helicopter borne surveys services
include multiple techniques (EM, MAG, Gamma Spectrometry and VLF) for
base metals, gold and Uranium exploration. These techniques may also be
applicable for other purposes such as detection of man made conductive
structures (pipelines and UXO) and environmental studies.
- Concrete structure evaluation
such as injection control, mechanical property evaluation and
reinforcement bar and duct detection in concrete slabs.
- Environmental studies
such as ground contamination mapping and contamination source studies.
GPR also offers services in ground water resources. Finally, GPR also
provides radioactivity measurement services.
- Geological and geotechnical
studies such as overburden and rock profiling, void and
sinkhole detection, site studies for civil engineering structures, dam
security and permafrost depth estimation.
- Marine geophysics and
hydrographic surveys. Including, construction site
evaluation, environmental studies, dredging monitoring and control,
sedimentation studies, immerged structures inspection and location,
hydrographic surveys and port redevelopment.
- Noise and vibration monitoring
in the mining, quarrying and construction sectors. This includes risk
analysis and estimation, as well as the sale, maintenance and rental of
seismic monitoring equipment.
- Oil and gas exploration.
- Underground detection
of buried objects, pipes, archaeological remains and UXO's.
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Heliborne surveys
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The principal
systems operated by Geophysics GPR are:
- HeliMAGer
gradiometer, a new high precision sampling data acquisition system
developed by Geophysics GPR;
- Geometrics high
sensitivity magnetometers with optical pumping technology;
- Spare parts for all systems available on
site ;
- A real-time DGPS navigation system
providing 1 metre in-flight precision;
- An radar altimeter providing ~1.5 metres
exactitude;
- On-site preliminary data processing
(final processing at our Montreal office);
- The data processing and mapping are
carried out by experienced geophysicists using powerful computers and
state-of-the-art software.
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HeliMAGer : Magnetic
total field / gradient surveys
HeliMAGer is a helicopter borne
tri-dimensional magnetic gradiometer developed by Geophysics
GPR. This system allows surveying with low ground clearance
therefore providing improvement in magnetic high frequencies response
and small magnetic anomalies definition.
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Gamma-ray
spectrometry - GRS-10 system
PICO Envirotec’s GRS-10
Radiometric system is an intelligent gamma-ray spectrometer made up of
four crystals of NaI (Tl) totalizing 16.8 l. The use of spectrometer
GRS-10 is very widespread in the mineral exploration industry and in
nuclear installation monitoring.
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Very Low Frequency
(VLF) EM surveys - Herz TOTEM-2A multichannel airborne system
The TOTEM-2A detects the electromagnetic
waves of very low frequency (from 15 to 25 kHz) coming from antennas
for submarines navigation and communication. These antennas are located
throughout the world. This system is used in the interpretation of
broad geological structures such as faults and surface conductors.
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Noise and vibration control
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Risk analysis and
technical specification preparation
The main goal of risk analysis related to
blasting operations is to protect clients against lawsuits that could
be made by neighbors as well as by the owner of the project.
A mine or quarry operator, a blasting
contractor or engineers are subject to lawsuits, whether justified or
not. The risks associated with each project need to be evaluated in
order to establish an approach that will be used throughout the project
in order to minimize the risk of lawsuits. The principal elements of
this approach are:
- Site evaluation
- Determination of vibration and air
overpressure limits
- Hydrogeological impact evaluation
- Underground infrastructure location
- Continuous structural stability
measurements
- Nearby fragile equipment inventory, such
as computers, scanners or other technical and medical devices
- Nearby structure report, pre-inspection
- Evaluate other specific problems related
to the work to be undertaken
- Establish a seismic and geological
control procedure, including instrumentation and measuring and
monitoring techniques to be used on the building site.
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Mines and quarries
Since its origin, Geophysics GPR
International has managed blasting efficiency at mines and quarries in
Canada. Over the years, GPR has acquired notable exposure, since this
type of work is often carried out in urban environments, near subway
stations or fragile buildings.
Blasting operations and environmental impact
control includes continuous monitoring of vibrations and air
overpressure, drilling, explosives and loading procedures. This also
includes blast property evaluation in terms of complaints and rock
physical parameters, particle velocity, air movement, projectiles and
other damage.
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Construction sites,
traffic and fragile equipment
Vibrations and noise due to blasting
operations, pile and sheet pile installation, dynamic compaction, heavy
machinery, traffic, etc. are constant problem sources. Not only do they
inconvenience people, but they can also cause deterioration of nearby
structures and fragile equipment.
In order to avoid such inconveniences and
costly reclamations, GPR offers a variety of services in vibration
control, including:
- Geological studies
- Evaluation of vibration limits
- Infrastructure location
- Pre inspection
- Evaluation of Hydrogeological conditions
- Blasting pattern design and approval
- Vibration monitoring
- Expert reports
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Sale, rental and
maintenance of NOMIS seismographs
In order to better serve its clients and due
to its expertise in geophysics and instrumentation, Geophysics GPR
International became an exclusive agent for NOMIS
Seismographs in Canada in March 1998. Geophysics
GPR offers the sale, rental, technical tutorials and calibration and
maintenance services for all types of NOMIS equipment.
Type 5400 and Mini-Graph 7000 seismographs
are entirely digital, adjustable to local site standards and compatible
with sophisticated data processing, allowing more efficient monitoring
of blasting operations.
Type 5400 seismographs are equipped with LCD
display, internal memory for over 100 events, RS-232 serial port,
continuous recording mode and a high quality printer. The Mini-Graph
7000 can record over 300 events and the event summaries are displayed
on an LCD screen.
Also, with our Microsis®
data acquisition system, Geophysics GPR can use different types of
sensors, depending on the required measuring requirements
(accelerometer, geophones, microphones, hydrophones, etc.)
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Underground detection
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Detection of
buried objects
The presence of underground objects such as
drums, tanks and other buried structures can indicate potential
environmental hazards. There are various geophysical methods that can
be used in order to detect these objects. Depending on the target and
overburden properties, electromagnetic methods
(e.g. EM-61, EM-31), ground penetrating radar
and earth
magnetics can be used to locate such buried objects.
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Conduit detection
The presence of pipes and conduits in the
ground or in concrete structures can be a problem when excavation or
boreholes are needed. Electromagnetic methods
(e.g. EM-61, EM-31), ground penetrating radar
and earth
magnetics are efficient methods of locating such
underground conduits. For concrete investigations, ground penetrating
radar can locate pipes, electrical cables, re-bars and other types of
conduits.
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Location of
archaeological remains
It is advisable to use non-destructive means
of investigation during archaeological fieldwork in order to minimize
the impact on the study site. The ground
penetrating radar method can facilitate location of
buried objects, building foundations, underground tunnels as well as
burial sites. In certain cases, electromagnetic methods
(EM-61, EM-31, etc. systems), earth magnetics and electrical
resistivity are other methods that can be used for
archaeological investigation.
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Unexploded Ordnance
(UXO) Detection
Unexploded Ordnance (UXO's) are usually
ferromagnetic objects. Geophysics GPR International can easily detect
these objects using earth magnetics
methods (magnetometer) or non-ferromagnetic objects using electromagnetic
methods (EM-61).
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Environment and contamination
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Contaminated soil
identification
The presence of contaminants (hydrocarbons,
acid mine drainage, etc.) in soil or in groundwater causes variations
in their physical properties. This enables some geophysical methods
such as electrical resistivity,
ground penetrating radar
or electromagnetic
methods (EM-31) to identify contaminant plume
boundaries. These methods can also be used to monitor contamination
evolution with regular surface or borehole
surveys.
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Contamination source
location
The presence of contaminants (hydrocarbons,
acid mine drainage, etc.) in soil or in groundwater causes variations
in their physical properties. This enables geophysical methods such as electrical
resistivity or electromagnetic methods
to trace contamination sources in soil or in groundwater.
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Groundwater
resources exploration
The use of geophysical methods for
groundwater exploration can be very valuable, especially for
determining drilling targets. Seismic and electromagnetic
methods are used to locate faults and rock
fractures containing groundwater. Seismic and electric
methods can identify the water table and aquifer limits. Within certain
conditions, ground penetrating radar
can also map the water table.
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Road and bridge evaluation
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Bitumen roads
Accurate road repair methods can be very
difficult when information regarding the thickness and quantity of the
existing surface is lacking. Indeed, examination of the layer
thicknesses can resolve conflicts between clients and
contractors. Georadar, as applied
to the evaluation of road surfaces, allows the efficient and precise
recording of bitumen thickness. Results are entirely digital,
and hence this information can easily be imported into a road
management software suite for further analysis.
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Concrete roads
Recently there has been an increase in the
use of concrete as a road surface, principally because they are much
more durable. However, repairs of these surfaces are much
more costly than those of bitumen surfaces. Therefore it is
very important to target only those areas where work is needed, in
order to keep the budget under control. The georadar
technique allows the mapping of surface deterioration to be carried out
efficiently and with precision. Whether it is for bridges,
roads, or multi-level parking structures, with or without a bitumen
layer, this technique has proven its worth.
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Concrete structure evaluation
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Grouting control
Seismic tomography
surveys can be performed prior to the planning of grouting work. The
resulting tomographic sections can help optimize grouting patterns and
orientation. Post-grouting tomography can help evaluate the grouting
efficiency.
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Mechanical concrete
assessment
The evaluation of the physical parameters of
concrete can be very important in order to determine the degree of
safety of large structures. Through the use of its cutting
edge acoustic measurement equipment, GPR is able to respond to
practically all testing needs, regardless of project size.
These instruments are not only used for the testing of concrete, but
can also be applied to the analysis of bedrock. For large
scale projects it is also worthwhile using the seismic refraction
technique since several kilometres can be covered in a period of
several days.
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Reinforcement and
conduit detection within concrete slabs
Geophysics GPR International is now
employing a brand-new georadar system for
automatic scanning of concrete slabs and walls. The speed and precision
of the system, combined with the vast experience of GPR, ensures very
efficient detection of conduits, re-bars and other objects within the
concrete.
Ideally suited for:
- Locating conduits before drilling
- Assessment of reinforcement structure
- Detection of cavities
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Oil and gas exploration
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Geophysics GPR has a vast experience when it
comes to the specialised field of petroleum exploration. During the
last 30 years, GPR has conducted successful prospecting surveys for
many clients all over Canada.
Along with its partners, Geophysics GPR
International, disposes of state of the art seismic
exploration equipment that enables precise location
of coal, natural gas and oil deposits, on land and over water.
Through the use of joint venture agreements,
GPR's unique expertise assures it of a privileged participation in many
projects led by the major petroleum and energy players.
GPR offers the following services:
- 2D and 3D seismic data acquisition and
processing
- magneticand gravity data acquisition and
processing
- regional sedimentary basin studies
- site surveys for offshore oil rigs
Contact us to discuss your future
exploration project requirements.
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Geology and geotechnics
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Soil and rock
characterisation
Seismic refraction is the method of choice
for soil land rock characterisation. This technique enables
us to determine the rock quality and to identify zones of weak
mechanical resistance, such as faults and fracture zones.
This method also allows us to determine the nature and degree of
alteration of the overburden.
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Cavity and
subsidence zone detection
The presence of cavities and subsidence can
present a risk, geotechnically speaking. Several geophysical
methods can be used in order to detect and locate these high risk
areas. The most current method used for this type of
investigation is georadar.
In certain conditions, electrical, seismic (reflection
and resonance)
or gravity
methods can also be used for the same purpose.
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Site investigation
for large projects
The use of geophysical techniques during
feasibility studies for large projects can significantly reduce overall
costs. The ideal method for this type of work is seismic
refraction, which provides several useful pieces if
information, including the thickness of overlying sediments, rock
quality, weak zones (fault and fracture zones), as well as the depth pf
the water table. When combined with geotechnical studies such
as drilling, this technique can precisely determine local site
characteristics.
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Rock and soil
geological profile
The seismic refraction
technique allows us to efficiently trace the geological profile of the
soil and bedrock. In this manner, it is possible to determine
the thickness of overlying sediments, rock quality and weak zones
(fault and fracture zones). In the case where several
different stratified rock formations are present, seismic
reflection allows the estimation of the thickness
of each different formation.
In certain cases, georadar
can also be applied to geological profiling of soil and rock.
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Depth to permafrost
The georadar technique is
the most efficient for the evaluation of the depth of permafrost in
cold climates. In certain specific cases, electrical
resistivity or seismic refraction can also be used
for this purpose.
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Dam safety
The inspection of the interior of dams can
be a sensitive subject when problems are suspected or become apparent
at the exterior (subsidence, channelling, alkali-granular reactions,
etc.). The use of different complementary geophysical
techniques enables the collection of a large quantity of useful
information concerning the state of the structures through the
association of the nature and characteristics of the construction
materials to different possible problems. The information
acquired through the use of geophysical means is complementary to
conventional drilling techniques and allows us to extend the punctual
information in a continuous fashion.
Depending on the type of dam structure and
the problem encountered, certain methods will be implemented in
preference over others. The main methods used are as follows:
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Marine geophysics and
hydrography
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Marine construction
site studies
Before detailed design of marine
constriction projects can begin, it is essential to have complete and
precise geotechnical information from the site. Through the
use of multidisciplinary surveys GPR is able to satisfy the
requirements of its clients in Canada and abroad for both small and
large projects.
For example, the classic pipeline / tunnel
corridor crossing a river or lake necessitates the acquisition of the
following information:
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Marine environmental
studies
Water sampling studies
In the case of pollutants that are
transported in the water of rivers or lakes, it is possible to conceive
a water sampling study in order to gain an understanding of the cause
of the pollution. Among the techniques that are used are:
Current measurements
using a specialized instrument;
Water sampling
at targeted points, followed by laboratory analysis;
Temperature, conductivity, and salinity measurements in-situ at
targeted points.
Sediment sampling studies
Often, pollutants accumulate in the
sediments of rivers or lakes. Through the use of specialised
sampling equipment, GPR can implement a sediment sampling
programme to collect sediments in marine environments. A
Benthos type sampler allows the extraction of sediment cores up to 2
meters thick. These samples can be analysed on-site or sent
to a laboratory for testing.
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Dredging control
studies
Dredging control is performed through the
use of bathymetric surveys prior to and post dredging
operations. These two datasets can be used to calculate the
volume of sediments dredged, and to assess whether adequate material
has been removed over the entire zone. The post dredge study
results can be used to create an up to date nautical chart based on a
specific vertical datum. (Chart datum, sea level,
etc.). Such a chart is often required by the authorities to
ensure navigational safety for waterways.
Through the use of modern bathymetric
techniques, GPR can rapidly cover any given area, over rivers, lakes or
oceans. With our expertise in single or multi-beam systems,
GPR is able to respond to your particular needs, whether big or small.
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Sedimentation studies
A basic sedimentation study implies high
precision bathymetric surveys repeated over a fixed time
interval. Using this information, estimates can be made on
the rate of sedimentation in navigation channels, upstream of dam
intakes, in ports or marinas etc. A more detailed study would
include additional types of measurements. A typical study would include
the following:
GPR has the experience and possesses the
necessary equipment required to carry out sedimentation studies
worldwide.
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Submerged structure
investigation
Submerged structures such as pipelines,
cables, dams etc. require regular inspections in order to ensure their
safe operation. In some situations, the use of divers alone
can be both dangerous and costly. Underwater inspections can
be made much more efficient and cost effective through the use of
modern technology.
The ideal tool for this type of work is
undoubtedly the side-scan sonar, or sector
scanning sonar system. These instruments
enable submerged structures / objects to be located and examined
through the use of acoustic waves which are not affected by water
turbidity. In addition, a marine magnetometer
may be used in order to detect ferrous objects located on the bottom of
bodies of water.
Today, the technology exists to permit the
examination of submerged structures using a high resolution swath bathymetric
system, such as the Geoacoustics Geoswath system. This system
will produce a high resolution 3-D model of any submerged structure,
such as dam walls and intakes.
GPR has significant experience in carrying
out inspection / checking of the submerged parts of dam walls in Canada
and abroad. These techniques have in addition been used to
locate lost objects such as ships rudders, wrecks and construction
debris.
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Hydrographic surveys
Hydrographic surveys are required in
navigable waterways, ports, harbours, marinas, etc. GPR has obtained a
vast experience in hydrographic surveys for maritime safety.
Most of the nautical charts for the St-Lawrence River around Montreal
were produced using data acquired by GPR.
Through the use of modern bathymetric
techniques, GPR is able to rapidly cover the required survey area in
order to assure the safety of the waterway. Data can be
provided in the form of soundings on a chart, or contours of constant
depth. The data can also be reduced with respect to the
vertical datum required by the client (e.g. Chart datum, local datum,
or Mean Sea Level).
With our expertise in single or multi-beam
systems, GPR is able to respond to your particular needs, whether big
or small.
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Port redevelopment
Geophysics GPR International Inc. have
carried out several large studies in order to facilitate the design of
redevelopment for ports and harbours, both in Canada and abroad.
In general, the differing types of study required for a port
redevelopment study are as follows:
Geophysics GPR International Inc. has the
expertise, experience and equipment required to carry out large
multidisciplinary projects throughout the world.
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