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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;
- GEM-2A: an advanced helicopter borne frequency domain electromagnetic system;
- 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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Frequency EM surveys - GEM-2A system
GEM-2A is a broadband frequency domain electromagnetic system designed and produced by Geophex Ltd. This system is used for localiting conductive anomalies and for ground resistivity mapping.
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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
| 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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