A basic introduction to available geophysical test methods for the use of Geotechnical engineers presented at the USACE Infrastructure Conference in Atlanta, June 2011.
A basic introduction to available geophysical test methods for the use of Geotechnical engineers presented at the USACE Infrastructure Conference in Atlanta, June 2011.
Integrated Geophysical Approach for Rapid & Cost Effective Site Investigation...IEI GSC
Dr. Sanjay Rana, Director, PARSAN Overseas (P) Limited
With inputs & examples from Dr Gopal Dhawan & Dr S L Kapil
at 31st National Convention of Civil Engineers
organised by
Gujarat State Center, The Institution of Engineers (India) at Ahmedabad
Shear wave velocity and Geology Based Seismic Microzonation of Port-au-Prince...Johana Sharmin
This is a presentation entirely based on the paper published by Brady R. Cox and his team. I just focused on the key points of the paper in the presentation.
Airborne gravity anomaly over Delta State in the Niger delta basin of Nigeria has been interpreted to obtain the structural trends/types and depth to basement in the state. The residual gravity anomaly obtained from a second order polynomial operation on the observed field data was enhanced by a first order filtering operation based on the regional geology. This was converted to a gridded data and analyzed qualitatively to reveal NS and EW trending subsurface structures. Inverse and forward modeling using Oasis Montaj software were applied to selected portions using geological models of sphere and dyke to reveal syncline and anticline structures at depths of between 2005 m to 7372 m, with density contrast of between 1.12 gcm-3 and 2.70 gcm-3. The Euler deconvolution operation with a structural index of one, reveal depths between 124.2 to 16,000 m. The results show that the maximum depth to basement in the area occurs in the northern part of the state with maximum depth of 16,000 m.
It covers seismic method, gravity method, electromagnetic method, magnetic method and radiometric method. all these methods help in mineral exploration
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
Integrated Geophysical Approach for Rapid & Cost Effective Site Investigation...IEI GSC
Dr. Sanjay Rana, Director, PARSAN Overseas (P) Limited
With inputs & examples from Dr Gopal Dhawan & Dr S L Kapil
at 31st National Convention of Civil Engineers
organised by
Gujarat State Center, The Institution of Engineers (India) at Ahmedabad
Shear wave velocity and Geology Based Seismic Microzonation of Port-au-Prince...Johana Sharmin
This is a presentation entirely based on the paper published by Brady R. Cox and his team. I just focused on the key points of the paper in the presentation.
Airborne gravity anomaly over Delta State in the Niger delta basin of Nigeria has been interpreted to obtain the structural trends/types and depth to basement in the state. The residual gravity anomaly obtained from a second order polynomial operation on the observed field data was enhanced by a first order filtering operation based on the regional geology. This was converted to a gridded data and analyzed qualitatively to reveal NS and EW trending subsurface structures. Inverse and forward modeling using Oasis Montaj software were applied to selected portions using geological models of sphere and dyke to reveal syncline and anticline structures at depths of between 2005 m to 7372 m, with density contrast of between 1.12 gcm-3 and 2.70 gcm-3. The Euler deconvolution operation with a structural index of one, reveal depths between 124.2 to 16,000 m. The results show that the maximum depth to basement in the area occurs in the northern part of the state with maximum depth of 16,000 m.
It covers seismic method, gravity method, electromagnetic method, magnetic method and radiometric method. all these methods help in mineral exploration
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
Structure-metric method FOR PREDICTIVE ESTIMATION of NATURAL RESOURCESKaterinaKaritskaya
Research Company offers performing forecast and estimation of presence of hydrocarbon fields by structurometric method. Structurometric method requires no field trips and provides significant time saving. Forecasts developed by structurometric method, in comparison with conventional exploration activities 3 times are more exact, by 1-2 orders more efficient, environment remains undisturbed.
Root-mean-square errors of definition of deposit depths and thickness of oil and gas formation according to numerous test wells do not exceed 4-5 % (at depths up to 4000 m.). There can be discovered productive formations at depths of 7 km and more, and also on a shelf at sea depth up to 450 m.
This method can be used rather productively by investors with the purpose of predictive estimations of resources of licensed sites and areas offered for right of land tenure.
Underwater,underground and surface investigationAndrei Tanasie
The geological structure and the pshysical-mechanical characteristics of the underground play an important role in designing buildings. Using direct methods such as open digging, drilling, sampling for laboratory tests, etc. and indirect geophysical methods, these characteristics can be determined with high precision. This method helps in making resistance and economical calculation.
Case studies of surveys involved in Railway Tunnel constructed under sea.Prudhvi Thota
Case Studies of detailed explanation of Hydro graphic survey, R.T.K. GPS, Seismic designing, profile survey etc involved in the construction and Designing aspects of Mammary Railway Tunnel under the sea.
Engineering geophysical study of unconsolidated top soil using shallow seismi...
20160602 Non-Invasive Geophysical Techniques
1. WE PUT YOU ON SOLID GROUND
www.infratecheng.com
19th Southeast Asian Geotechnical Conference & 2nd AGSSEA Conference (19SEAGC &
2AGSSEA) Kuala Lumpur 31 May – 3 June 2016
The use of Non-Invasive Geophysical
Techniques to build 3-Dimensional ground
models and reduce the cost and risk of site
investigation
Sam Setchell, Muhammad Azrief bin Azahar,
Qusanssori Noor bin Rusli and Nick Lowe
2. Presentation Outline
Site Investigations
Geophysical Techniques
Towards 3D models
Case Studies
Langat Sewer, KL
Meru Landfill, Western Australia
Cominco Phosphate Project, Republic of the Congo
3. Site Investigations
Geotechnical Hazards present a major project
risk.
Site Investigation – Relies on expensive drilling to gain
information on ground conditions
‘Point’ data means a conservative approach much
be taken
More Data = Better geotechnical model = Lower
Risk
Non-Invasive techniques – to reduce risk
4. Geophysics - ideally suited to
geotechnical site
investigations
Provides Engineering
Parameters without the need
for drilling
Quickly and cheaply maps
variability – allows refined
and reduced drilling
Can be converted into 3D
ground models
Geophysical Site Investigation
5. Multi Channel Analysis of Surface
Waves – MASW
Measures 2D profile of
compressibility / strength of soils
and rocks
Continuous analysis of surface
waves – CSWS
Measures 1D profile of
compressibility in high resolution
Ground Penetrating Radar – GPR
High resolution 2D scans that
quickly highlight depth to
features as well as voids.
Geophysical Techniques pt. 1
6. Gravity Techniques
geological features, man-
made structures and
voids
Electrical Resistivity
Tomography (ERT)
Measures 2D profile of
resistivity of sub surface
materials
Ground Conductivity – EM
Magnetics
Geophysical Techniques pt. 2
7. MASW Technique
The MASW Technique utilises surface
waves elastic condition (stiffness) of the
ground for geotechnical engineering
purposes.
A 2D Map of ground stiffness – in terms of
sear-wave velocity (Vs) is created
8. 3D models of ground conditions can be
created by non invasive techniques
11. Calibrating the Model
Compressibility
High Medium Low
SPT N-Values from
subsequent drilling
investigation
Some lag, but otherwise good agreement between MASW and
SPTn
Compressible
layers lead to
rapid reduction
in SPT n
12. Depth to Bedrock
Use of CSWS technique
allowed identification of
variable depth to
bedrock under
residential development
in Fremantle.
Surface represents
inferred top of bedrock.
This was then verified
with just 1 borehole
13. Detailed Case Study – Langat Sewer
Study to measure the
depth to bedrock along the
alignment of a proposed
sewer
Directional drilling to be
undertaken → strength of
soil very important
CSWS and SASW used to fill
in gaps from pre-existing
bore hole data.
14. Langat Sewer
Advantages of CSWS/SASW over
drilling:
Data could be collected from
the actual pipeline alignment –
drilling had been taking place
up to 50m away.
10 tests a day – much greater
coverage of data
Little disturbance to traffic
Cheaper for the client
17. Detailed Case Study – Langat Sewer
Profiles were produced for
the whole sewer alignment
Amount of data collected
allowed client to make
decisions and reroute some
areas of pipeline
Over all a successful
application of a
geophysical method!
18. Meru Landfill – Using
geophysics to plan location
Limestone outcrops had been found on the site of proposed landfill
development
The previous landfill cell encountered unforeseen rock at shallow levels,
resulting in a significant cost overrun (for excavation)
A 4 month drilling campaign was proposed to identify the extent of this
limestone with an estimated budget of A$650,000.00 (~2 million ringgit)
- almost 3 times what was allowed.
The critical aspect was to get complete (or close to complete) 3D
coverage across the site.
The MASW technique (Multi Channel Analyses of Surface Waves) was
chosen by Infra Tech.
Completed within a budget of A$75,000.00. (~232,000.00 ringgit)
21. 2D to 3D conversion
Fence diagram
shows clear
band of rock
material
22. Blocks representing
‘limestone’ can be isolated
and an estimation of volume
of limestone material can be
made – all before drilling!
3D Block Model
23. Presentation Conclusions
Inadequate site investigations can lead to project
failure (or worse)
Geophysical techniques provide a cheep and quick
way to gather information
Add value by:
Reducing Risk – better site understanding
Reducing drilling cost
Creating more accurate ground models
24. THANK YOU
WE PUT YOU ON SOLID GROUND
FASTER, STRONGER, CHEAPER, SAFER, GREENER
Editor's Notes
No firm identification or logo allowed on any sheet except the cover sheet (slide 1 of this template).
Authors may choose either the horizontal or vertical format for their presentation.
No firm identification or logo allowed on any sheet except the cover sheet (slide 1 of this template).
Authors may choose either the horizontal or vertical format for their presentation.
With the controlled surface wave system it is the element of control that is the main advance from sasw. An industrial vibrator that can be controlled in frequency to 0.1 Hz resolution.
With the controlled surface wave system it is the element of control that is the main advance from sasw. An industrial vibrator that can be controlled in frequency to 0.1 Hz resolution.
With the controlled surface wave system it is the element of control that is the main advance from sasw. An industrial vibrator that can be controlled in frequency to 0.1 Hz resolution.
With the controlled surface wave system it is the element of control that is the main advance from sasw. An industrial vibrator that can be controlled in frequency to 0.1 Hz resolution.
