standard cut vs. keyhole - apwa home · 2005. 9. 21. · standard dcp stone-base 2 blow/inch...
TRANSCRIPT
-
1
1
KEYHOLE TECHNOLOGY An O&M Infrastructure Management Tool For
the 21st Century
Utility Micro-Surgery
2005 APWA International Public Works Congress and Exposition
Tuesday, 13 September 2005
T. Mark Andraka---- Sr. Engineer
2
Standard Cut vs. Keyhole
3’ x 4’
1.5’ x 1.5’
10” or 18”
3
Small Hole Encapsulation Work1980- 1990 Vintage
-
2
4
Infrastructure Installations and Repairs made Safely– Efficiently--
From above the hole
Photo Credit Omega Servac
5
Keyhole Opportunities
Reduce Restoring Costs
Coring
Urban Microsurgery2000– Plymouth Twp. Completion of GTI Reducing Excavation And Restoration Project Phase II2001---GTI Keyhole Workshops— Phoenix AZ & Hartford CT 2003–Ongoing---- GTI Keyhole RC Project
6
Pipeline & Gas Journal
“New Technologies, Close Coordination Save PECO Energy $1M”August, 2002
Mark AndrakaBrian CamfieldBill HuttonAllen Spivey
-
3
7
Enhancements to Vac Technology Resulting from
PilotTeamed with SerVac/Omega & GTI
Trailer Vac Unit with Mobile Dump ValveHose Assisted Unit –One Man Soil Breakup and VacuumStorage area for PipehawkAir-Water Knife
8
Standard Cut
Standard Cut3’X4’’Excavation
Excavate +/- pipe
In-hole repair process
Temporary black-top
Cut-backs
Separate Re-pave Contractor
Dumping & Transportation Fees
Up to 6 week time frame start to finish
Keyhole10”—18” Excavation No need to excavate below pipeAbove ground repair process
Core reinstated-- No cut backs Homogeneous materials Can be performed year-roundMinimal Impact to Traffic Flow and PublicJob Complete prior to crew leaving site
9
Our Challenge
Enhancement and Introduction of New Technologies into Operations
Technologies accepted into work forceThe right technology for the right circumstance
-
4
10
THE PECO Energy Keyhole Technology Development Project
A SerVac/Omega-GTI-PECO Coordinated Effort2003-2004
Tools & ProcessesExcavationsCore HoleNo Cut-BackOne Day Complete JobMicro-ExcavationLocatingPin-pointingLeaksFacilitiesLess Time to Complete JobLess Customer DisruptionsMore Core Business with LessTrue Two-Person TeamComplete --Start-Finish
11
Pavement Coring Machines
6”, 8”, 10” or 18” Cores
12
Rotary Cutter for Cores-- Different Depths & Compositions
Thin Asphalt Thick Asphalt
Thick Composite and Reinforced Concrete
-
5
13
Core ReinstatementBackfill & Compact
Grout Mixture
Core Placement Finished Repair
14
Excavation Tools
Air Knife / Air Spade Water Jetter
15
Specialized O&M Tools
Extend
ed Ha
ndle
w/Deta
chable
Tools
-
6
16
PECO Energy O&M Processes
17
New and Replacement Services Installed
18
Anode and Test Station Installations
-
7
19
Curb Valve Installations
> Credit collection
> Safety
20
… 30 Minutes Later -- Open for Traffic!
Completed repair almost invisible.
No overnight road plating
Restoration is traffic bearing in 30 minutes
No return trips to make final restoration
21
What does this mean for the Road? - Improved Pavement
Performance!Size Matters! Keyhole is 80% smaller than conventional utility cut --more aesthetically pleasing with less damage to road systemPrecision core cutting avoids collateral damage to road --no backhoes, jackhammers and over cuts from concrete sawsNo temporary patching.Replaced core exactly matches composition of original roadReinstates road to original weight bearing capacity
-
8
22
Post Job Process
F(Direction of Traffic Flow)
R
L Core Hole Grout Line
Test Point Holes
CMT
23
Cold Weather Process
24
Enhancements for MainstreamLocation Location Location
-
9
25
A SolutionA New Way to Undertake Our Infrastructure O& M
Processes
Inactive Gas Service Cut-offs
Past
Future
-
1
Soil Compaction Measuring Device Study
Presented to APWA 2005 Conference
- Daniel Vetter, P.E.Gas Technology Institute - GTI
Tuesday 13 September 2005
Soil Compaction Measuring Device Study
Outline of Presentation
Objectives
Testing Program
Tools
Results & correlations
Conclusions & Recommendations
Soil Compaction Measuring Device Study
Objectives ..
Provide the Inter-Agency with an evaluation of the currently available soil compaction measuring devices as an alternative to the Nuclear Density Gauge [NDG].
-
2
Soil Compaction Measuring Device Study
Objectives ..
Why replace the NDG?
Operator must be trained and licensed
Company must have EPA approval
Storage, transport and disposal of unit must be monitored
Soil Compaction Measuring Device Study
Objectives ..
Why replace the NDG?
EPA initiative to investigate alternative devices
FHWA research plans to develop alternative compaction control devices.
Soil Compaction Measuring Device Study
Objectives .. Why replace the NDG?
Not the best device in cuts. Readings near trench walls are affected by sidewall boundaries
“Offsets may be required .. if the material has concrete, some coal, and ferrous soils . . The gauge requires an offset if measurements are taken inside a trench…” Troxler Manual, model 3440
-
3
Soil Compaction Measuring Device Study
0
10
20
30
40
50
60
0 5 10 15Distance from side wall (inch)
% I
ncr
ea
se i
n m
ois
ture
co
nte
nt
.
4-inch probe
8-inch probe
12-inch probe
The Nuclear Density Gauge
Soil Compaction Measuring Device Study
Sand Backfill0
6
12
18
24
30
36
0 10 20 30
Moisture Content [%]
Keyh
ole
Dep
th (in
ch)
NDG Moisture
Oven Moisture
The Nuclear Density Gauge
Soil Compaction Measuring Device Study
Soil Compaction-Measuring Devices
Testing Program
-
4
Soil Compaction Measuring Device Study
Determine Backfill Properties
0
10
20
30
40
50
60
70
80
90
100
0.0010.0100.1001.00010.000100.000Sieve Opening (mm)
% Pa
ssin
g
NJ-Sand
IL-Sand
Silty-Clay
Stone-Base
Soil Compaction Measuring Device Study
Determine Compaction Properties
ControlBackfill Moisture in all Test layers
Soil Compaction Measuring Device Study
In-Process Devices (Q/C)
Soil Compaction Supervisor(SCS)
Utility DCP
GeoGauge
Clegg Hammers
-
5
Soil Compaction Measuring Device Study
Post-Compaction Devices (Q/A)
Standard DCP
PANDA Meter
Soil Compaction Measuring Device Study
These devices were evaluated with respect to the Control Devices:
Nuclear Density Gauge
Sand-Cone Apparatus
and the Ag. Moisture Gauges
Soil Compaction Measuring Device Study
Tests in Bellhole Sections
-
6
Soil Compaction Measuring Device Study
Tests inTrench Sections
Soil Compaction Measuring Device Study
Tests inKeyhole Sections
Soil Compaction Measuring Device Study
Soil Compaction Supervisor (SCS)
Easy–Minimal trainingEase of use-Training
WorkerOperator skill
NoneASTM Standard
FairDurability
GoodPortability
Pre-set SystemCalibration of Device
NoMoisture Readings
Max. Attainable Compaction (Pass/Fail)
Measurement
-
7
Soil Compaction Measuring Device Study
Soil Compaction Supervisor (SCS)
GoodOutput Consistency
N/ASurface Readings
Up to 30 inchesDepth of Reading
YesKeyhole Application
No effectTrench Boundary
Stores in memory(needs enhancement)
Data Storage
QC [continuous during compaction]
QC–QA Application
Soil Compaction Measuring Device Study
Utility DCP
Easy –Minimal trainingEase of use-Training
WorkerOperator skill
NoneASTM Standard
GoodDurability
GoodPortability
NoCalibration of Device
NoMoisture Readings
Penetration (blow count)Measurement
Soil Compaction Measuring Device Study
Utility DCP
FairOutput Consistency
Unreliable in top 3 in. in sand
Surface Readings
Up to 8 inchesDepth of Reading
Needs extension rodKeyhole Application
No effectTrench Boundary
Manual recordingData Storage
QCQC–QA Application
-
8
Soil Compaction Measuring Device Study
Utility DCP
11Stone-Base
22 Silty-Clay
4-6Sand
Acceptance Criteria (*)
Soil Type
(*) - Acceptance Criteria is for 90% Modified Relative Compaction
- Previous device calibrations in sand had acceptance criteria of 6
Soil Compaction Measuring Device Study
GeoGauge
Easy-Minimal trainingEase of use-Training
WorkerOperator skill
ASTM 6758ASTM Standard
GoodDurability
GoodPortability
calibration plateCalibration of Device
NoMoisture Readings
Soil Stiffness & Young’s Modules
Measurement
Soil Compaction Measuring Device Study
GeoGauge
FairOutput Consistency
Sensitive to surface stiffnessSurface Readings
9 inches as per manufacturer[not confirmed in tests]
Depth of Reading
NoKeyhole Application
affected by side wallTrench Boundary
Stores DataData Storage
QCQC–QA Application
-
9
Soil Compaction Measuring Device Study
GeoGauge
No correlationStone-Base
45Silty-Clay
30Sand
Acceptance Criteria (*)
Soil Type
(*) - Acceptance Criteria is for 90% ModifiedRelative Compaction
- Previous studies by FHWA showed acceptance values from 25 to 36 for A-3 and A-4 subgrade.
Soil Compaction Measuring Device Study
Clegg Hammers
Easy –Minimal trainingEase of use-Training
WorkerOperator skill
ASTM D-5874ASTM Standard
PoorDurability
MediumPortability
Factory calibratedCalibration of Device
NoMoisture Readings
Clegg Impact Value (IV)Measurement
Soil Compaction Measuring Device Study
Clegg Hammers
MediumOutput Consistency
Sensitive to surface stiffness
Surface Readings
About 8 inchesDepth of Reading
YesKeyhole Application
No effect Trench Boundary
Manual displayData Storage
QCQC–QA Application
-
10
Soil Compaction Measuring Device Study
Clegg Hammers
914Stone-Base
6 8 Silty-Clay
5 6 Sand
Clegg Hammer20-Kg
Clegg Hammer10-Kg
Soil Type
(*) - Acceptance Criteria is for 90% Modified Relative Compaction.
- Previous studies on device presented a calibration with soil CBR ratio.
Soil Compaction Measuring Device Study
Standard DCP
Easy-Require data plottingEase of use-Training
WorkerOperator skill
ASTM D-6951ASTM Standard
GoodDurability
MediumPortability
NoCalibration of Device
NoMoisture Readings
Penetration (blow count)Measurement
Soil Compaction Measuring Device Study
Standard DCP
GoodOutput Consistency
Not recommended for top 6 inches in sand
Surface Readings
Full depth (up to 3 ft)Depth of Reading
YesKeyhole Application
No effectTrench Boundary
Manual recording (can be Automatic)
Data Storage
QA [Full depth]QC–QA Application
-
11
Soil Compaction Measuring Device Study
Standard DCP
2 blow/inchStone-Base
5 blow/inchSilty-Clay
1.1 blow/inchSand
Acceptance Criteria
Soil Type
(*) - Acceptance Criteria for 90% Modified Relative Compaction
- Previous studies by Mn-DOT in granular base recommended 0.75 inch/blow (1.33 blow/inch)
Soil Compaction Measuring Device Study
The Panda
Extensive trainingEase of use-Training
TechnicianOperator skill
(French Standard)ASTM Standard
GoodDurability
MediumPortability
Factory calibratedCalibration of Device
NoMoisture Readings
Tip Resistance & Penetration
Measurement
Soil Compaction Measuring Device Study
The Panda
GoodOutput Consistency
Not recommended for top 6 inches in sand
Surface Readings
Full depth (extension rods)
Depth of Reading
YesKeyhole Application
No effectTrench Boundary
Stores in memoryData Storage
QA [Full depth]QC–QA Application
-
12
Soil Compaction Measuring Device Study
Summary
QC devices are the tools needed for layer-by-layer compaction control of restored utility cuts.
The output of the devices provide a measure of soil densification.
The acceptance criteria were determined based on for 90% Modified Compaction at optimum moisture contents.
Soil Compaction Measuring Device Study
Acceptance criteria can be achieved bycontrolling the moisture, lift thickness to 6-9 inches, and by using the appropriate compaction tools.
The Utility DCP, the 10-kg Clegg Hammer, and the SCS were the three QC devices that had the best qualities for utility restoration work.
Summary
Soil Compaction Measuring Device Study
Recommendations – Utility DCP
Improve drop height and handle design
Add-on drop weight
Storage and downloading capabilities
Easy user interface for location information
Add-on moisture measurement
Handle extension for use in small-hole excavations
-
13
Soil Compaction Measuring Device Study
Recommendations – Clegg Hammer
Redesign of guide tube and improve cable connections
Improve movability: Carrying case and cart
Add storage and downloading capabilities
Easy user interface for location information
Add-on moisture measurement
Handle extension for small-hole excavations
Soil Compaction Measuring Device Study
Recommendations – SCS
Include numerical readout to define acceptance values
Increase sensor depth range
Add button and/or light for new holes
Improve compactor type identification
Modify data storage
Easy user interface for location information
Add-on moisture measurement capability
Soil Compaction Measuring Device Study
Questions?
Soil Compaction Measuring Device Study