MERIT

Multi-Electrode Resistivity Implant Technique
MERIT
A New Tool For Subsurface Investigations
Presented by: David Harro PG
Why Is Imaging Important ?
Greatest Value of Geophysics
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•
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•
•
Speed 21%
Cost Benefit 19%
Better Characterization 17%
2D 3D Assessments 15%
Result Presentation 10%
What is Needed for Reliable Geophysical Imaging
Provide a
Complete
Profile
Direct Locations
Of Investigations
Overlap or
Surpass Depth
of SPT
Types of Geophysical Methods
GPR
Multi-electrode Electrical Resistivity (MER)
Our New Approach Is Well Under Way
Multiple Electrode Resistivity Implant Technique
(MERIT)
Clay
Limestone
Our Team
Dr Sarah Kruse
Geophysicist
Dr. M H Loke
Theoretical
Geophysicist
David Harro PG
Geophysicist
(Inventor of MERIT)
Henok Kiflu
Geophysicist
Dr. Paul Wilkinson
Theoretical
Geophysicist
What Makes MERIT Different ?
Geophysical Survey Distance 150’
Surface Methods
MERIT
Array
MERIT
Surface
Methods
30’ Feet
MERIT
60’
Feet
Optimized Tomography = Higher Resolution
250
Data
Points
1000+
Data
Points
Forward Model of Surface ER versus MERIT
Forward Model
Targets
MER Results
MERIT Results
CASE STUDY:
BORDEAUX VILLAGE SINKHOLE
Case Study: Bordeaux Village Sinkhole and USF
USF Site
Bordeaux
Site
Case Study: Bordeaux Village Sinkhole
Photo Courtesy of WTSP
Photo Curiosity America Red Cross
Case Study: Bordeaux Village Sinkhole
Photo Courtesy of WTSP
Case Study: Bordeaux Village Sinkhole Surface ER vs MERIT
MERIT
 Limestone
Surface
Geometry Seen
 Penetration 70
Feet
ER
 Surface of Clay
 Penetration 36
Feet
 Limestone
Surface Not
Seen
Case Study: Bordeaux Village Sinkhole
Sinkhole
B-1
Sand
B-2
Clay
70
Feet
Implants
30 Feet
Limestone
Car
Possible Investigation Using MERIT
Sand
CPT
B-1
B-2
Clay
Sinkhole
Limestone
MERIT can help direct geotechnical investigations and resources
CASE STUDY:
FLORIDA TURNPIKE “SINKHOLE”
ORLANDO, FLORIDA
Impact Range of Sinkhole
200 FEET
North
The Sinkhole
Impact of Sinkhole
Geotechnical Investigation for Sinkhole
Impact of Sinkhole
60
Feet
Sinkhole
Installing MERIT
MERIT Line 1
Impact of Sinkhole
MERIT Line 2
MERIT Results
 MERIT identified anomaly where SPT did not clearly
identify sinkhole conditions
 MERIT anomalies located where damage and movement of
the water main
 MERIT results help more clearly identify the risk that lateral
movement occurred and could potentially affect the water
main
We can still do more ……..
CASE STUDY: WEKIVA PARKWAY
Case Study: Wekiva Parkway
70
Feet
Case Study: Wekiva Parkway Section 5 Site B
MERIT primary line
Case Study: Wekiva Parkway Section 5 Site B
GPR Survey
25 Feet
Case Study: Wekiva Parkway Geotech Results
GPR Coverage
Case Study: Wekiva Parkway Geotech Results
Forward Model
(Feet)
Results: Wekiva Parkway Section 5 Site B
Stratum 1
(SP, SP-SM)
Stratum 2
(SM, SC, PT, ML)
Stratum 3
WEATHERED L/S
Stratum 4
COMPETENT L/S
COMPETENT L/S
(Feet)
(Feet)
Results: Wekiva Parkway Section 5 Site B
Stratum 1
(SP, SP-SM)
Stratum 2
(SM, SC, PT, ML)
Stratum 3
WEATHERED L/S
Stratum 4
COMPETENT L/S
COMPETENT L/S
(Feet)
Results: Wekiva Parkway Section 5 Site B
Results: Wekiva Parkway Section 5 Site B
Results: Wekiva Parkway Section 5 Site B
MERIT Coverage
Case Study: Former Landfill Tampa, Florida
(Feet)
Design A
Foundation Design B
Foundation Design A
Stratum 1
(SP, SP-SM)
Stratum 2
(SM, SC, PT, ML)
Stratum 3
WEATHERED L/S
Stratum 4
COMPETENT L/S
COMPETENT L/S
(Feet)
MERIT Results
 MERIT improved the understanding of the subsurface over
the SPT and CPT in complex geologic environments
 MERIT provide a frame work to correlate CPT data
 MERIT provided images so that alternative methodologies
for foundation stabilization could be explored (Design A and
Design B
What Can we do for you ?
Design Build
Still more to come….
Benefits of the MERIT Subsurface Imaging Technology
 Expose and help reduce risk
 Provide better estimates for deep foundations
 Reduce cost overruns associated with timely delays
and redesigns
Discussion: How Can We Help You?