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					                                                                         9/10/2009




           KEYHOLE TECHNOLOGY:
                   Micro-
          Pavement Micro-Surgery

          American Public Works Association
                    September 13, 2009


T. Mark Andraka---- Sr. Engineer - PECO Energy - Philadelphia, PA
     Utility perspective
Murv Morehead--- ROW Coordinator - City of Overland Park, KS
     Municipality perspective
Dennis R. Jarnecke---- Program Manager - GTI - Chicago, IL
     Research perspective




      What is Keyhole Technology?
         Method of accessing or viewing underground utilities through
         small holes or “keyholes”

         Vacuum excavated through soft surfaces or through holes cored
         through pavement.




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        Why Keyhole and Coring?
     A better, smarter and environmentally sensitive
     way of making and repairing utility cuts
     through pavement to:
       R d       d l
       Reduce delays and di        ti    f traffic d bli
                           d disruption of t ffi and public
       inconvenience during roadwork
       Minimize damage to roads
       Reduce impact of public works construction on the
       environment
       Facilitate repairs to underground utilities
       Improve worker safety and productivity through better
       I             k      f t   d     d ti it th     h b tt
       excavation methods
       Avoid damage to underground utilities during excavation
       or HDD (“Potholing”)
       Locate and map underground utilities (S.U.E.)
       Save utilities and their contractors time and money




PECO Operations & Territory
    1.6 million electric
                 490 000
    customers / 490,000                              Bucks


    gas customers
    6100 miles of gas                      Montgomery


    distribution pipe
                                                        Philadelphia
    229 municipalities &        Chester
                                          D l
                                          Delaware
    boroughs
    b     h
    PADOT and 5
    counties

4




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                GIROW
     Gas Industry Right of Way

                   AGA Committee Presentations

                            APWA--- UPROW
                               Sub-Committee
                LOCAL CHAPTER INVOLVEMENT




The GIROW Vision
 A 3 Prong Approach….

    1. Communicate and Educate
    2. Research & Studies
    3. New Technology
        (acquisition ≠ implementation)




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Standard Cut vs. Keyhole
                                    1.5’ x 1.5’


          3’ x 4’




                                   10” or 18”




        Small Hole Encapsulation Work
              1980-
              1980- 1990 Vintage




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Infrastructure Installations and Repairs made
Safely– Efficiently-- From above the hole




                               Photo Credit Omega Servac




The Coring Process




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   Standard Cut                           Keyhole
      3’X4’’Excavation                  10”—
                                        10”—18” Excavation
                                        No need to excavate below pipe
               +/-
      Excavate +/- pipe
                                        Above ground repair process
      In-
      In-hole repair process
                black-
      Temporary black-top                    reinstated--
                                        Core reinstated-- No cut backs
      Cut-
      Cut-backs                         Homogeneous materials
                                        H                 t i l
                                                           year-
                                        Can be performed year-round
               Re-
      Separate Re-pave Contractor
                                        Minimal Impact to Traffic Flow and Public
      Dumping & Transportation Fees     Job Complete prior to crew leaving site
     Up to 6 week time frame start to
     finish




               Standard Cut




THE PECO Energy Keyhole Technology Development Project:
A SerVac/Omega-GTI-PECO Coordinated Effort

Tools & Processes
• Excavations
• Core Hole
• No Cut-Back
• One Day Complete Job
• Micro-Excavation
• Locating
• Pin-pointing
• Leaks
• Facilities
  Less Ti
• L          to Complete J b
        Time t C     l t Job
• Less Customer Disruptions
• More Core Business with Less
• True Two-Person Team
• Complete --Start-Finish




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Specialized O&M Tools




Enhancements for Mainstream
Internal Inspection




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 … 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




What does this mean for the Road?
Improved Pavement Performance!
           Size Matters! Keyhole is 80%
           smaller than conventional
           utility cut -- more
                th ti ll l     i    ith
           aesthetically pleasing with
           less damage to road system
           Precision core cutting avoids
           collateral damage to road --
           no backhoes, jackhammers
           and over cuts from concrete
           saws
                         patching.
           No temporary patching.
           Replaced core exactly
           matches composition of
           original road
           Reinstates road to original
           weight bearing capacity
           Circular geometry eliminates
           corner stress cracks




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                                             9/10/2009




  A New Solution for Undertaking Gas
     Infrastructure O&M Processes


  Inactive Gas
         Cut-
 Service Cut-offs




Overland Park – Case Study
 2nd largest city in Kansas – suburb of KC
                 174,000
 Population of 174 000
 Encompasses about 75 sq. miles
 1,811 lane miles
 $20 + million annual Public Works
 budget
 City owns storm sewer system, street
 light/signal systems and fiber optic
 network




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                           9/10/2009




Why bother to visually
locate buried utilities?


       To   id
       T avoid…




         Damages




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More damages
When you damage a water line…




                                     There will be a mess




…still more
                                 Unlocated PVC water line




 Unknown obstacles caused drill stem to flex




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                                                9/10/2009




               Major damage
30” water
transmission main
HDD backreamer
scarred pipe
$86,000+ street
repair cost
Damage caused
contractor to go out
of business




                           Water under 125psi
                           can do this…




10,000+ cars per day
affected by closed lanes
for 3 weeks




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                                                9/10/2009




These and other damages taught us that it is
ABSOLUTELY MANDATORY to positively
visually locate ALL known existing utilities.
            l        ki    i t locate
DO NOT rely on marking paint or l       t
flags.

The entire dimension of the utility must be
         j     p    g         p
known – just exposing the “top” leaves too
much to chance.




          Lessons Learned
With many utility lines
under pavement that
need to be visually
located prior to any
trenchless activity
and to avoid this…




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                                                  9/10/2009




       Lessons Learned
 We now mandate all explorations/
        g                              pavement
 investigations for/of utilities under p
 use the keyhole/coring and reinstatement
 method.
 This method consists of core drilling through
 pavement, using vacuum excavation for sub
                                 found,
 grade removal until utility is found temporary
 street plating if necessary and reinstating
 core.




Core Drilling




           Hand held manual core drill




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Core Drilling




         Vacuum base manual core drill




Core being loosened for removal




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 Cores drilled and removed




4 small holes as opposed to the large excavation that would
normally occur...




 Vacuum Excavation
    Non-destructive Vacuum Excavation is the
    preferred method for locating buried utilities




       Trailer mounted unit          Large truck mounted unit




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What vacuum excavating can do…


 This 30” deep hole to
 locate a cable TV line
 was completed in 26
 seconds using hydro
 vacuum excavation




Vacuum excavation at work




                 Sub grade removal




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 When a traditional excavation is made in
 the street it must be plated…

  q
Requires machine to move

Must be secured to street

Leading and trailing edge ramps
must be placed

Subject to movement from traffic

Guaranteed to generate noise
complaints

                                              Typical street plate




                                   Street Plate



                                                                Streetlight




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                                                               9/10/2009




 Plate used for core drilled hole
Steel plate used to
temporarily cover
     hole
core h l is:

  Easily placed

  Virtually impossible to
  slide out of place

  Maintenance free

  Very low cost




 Backfilling




    Backfilling with CLSM (Controlled Low Strength Material)




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Reinstated core




                The finished product




  Bonding agents available on the market
  today can provide a load bearing strength of
  50,000 lbs. within 30 minutes of placement
  which is significantly higher than the
  requirements of AASHTO H-25 load bearing
  safety standards. This also provides a
  waterproof seal which will eliminate water
  infiltration into the sub grade. In addition, the
  repair is virtually invisible and therefore
  aesthetically pleasing.




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Repaired area…




    Which would you prefer on your streets?




How does a municipality benefit from
the keyhole/coring method?




       No more of these maintenance problems




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Problems with square holes…
                            Joint can be source
                            of water infiltration into
                            sub grade




  Cracks radiate out from
  corners




 An additional problem with traditional
 excavation methods is the “loss of confining
 stresses” in the area immediately
                    excavation.
 surrounding the excavation Numerous
 studies have shown that this condition allows
 the subsoil to “stretch” towards the open cut
 face and in it’s wake leaves an area of
 influence (lessoned compaction) up to three
 feet in all directions from the actual
 excavation.




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                                                         9/10/2009




EXCAVATION IMPACTS
                           Cut pavements have
                           poorer PCI ratings than
                           uncut
                           Utility cuts reduce
                           pavement life
                           Cuts reduce pavement
                           strength and integrity,
                           allow water penetration
                           “A patch is considered a
                           pavement defect no matter
                           how well it is performing”.




Keyhole/Coring vs. Traditional
Jackhammer/Backhoe method
Benefits
              y
  Substantially shorter duration traffic
  interruptions (i.e. lane closures)
  Far less damage to street
  Much faster operation
  Much cleaner operation
  Fewer and smaller pieces of equipment
  needed
  R d     d       i     t for    t t
  Reduced repair costs f contractor

Disadvantages
  ?




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                                                                                  9/10/2009




WHO WE ARE

Gas Technology Institute (GTI)
              Leading U.S. research, development,
              and training organization serving the
              natural gas and energy markets
                t l          d            k t


              Headquarters: Des Plaines, IL
                300,000 sq-ft facility, 18-acre
                campus

                    p o at o
                  Exploration & Production
                                  oduct o                          p
                                                  Distribution & Pipeline
                        Technology                      Technology

                   Non-conventional Fuels               End Use
                                                        Solutions

                    Serving the Energy Industry Since 1941




        Environmental Benefit of Coring
        and Reinstatement Process
               Reuses the same material, in the same form, to repair
               pavementt
                  no additional processing needed
                  no additional energy consumed
               No pavement spoil to be trucked away to dump site
               No new pavement laid, no milling & overlay, no slurry etc.
                  no volatile organic compounds to evaporate
  “It’s not
  easy            fewer emissions
  being
  green.”         no additional energy or oil consumed in producing/heating HMA
               Shorter and Fewer Road Closings
                  road can be safely reopened to traffic in 30 minutes
                  permanent repair -- no additional site visits
                  reduced inspection & traffic control requirements




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                                                      9/10/2009




Sustainability in Public Works
       Sustainability in Public Works is best
       encapsulated in the phrase “everything
           do ith            t th f t
       we d with an eye to the future”.   ”
       Be mindful of the fact that the resources we
       need today must also be available for
       those to come after us.
       In a sustainable society, environmental
       protection, economic objectives, and social
       justice join together to meet the needs of
       today without compromising the ability of
       future generations to meet the needs of
       tomorrow.




Sustainability Issues from the
UPROW Committee
  “Think out of the box” – develop and embrace
                                      today s
  new technologies not just to meet today’s needs
  but ones that will have positive long lasting
  effects. The emphasis should be on “how will
  our actions of today affect tomorrow”.
  Increase use of recycled materials ( i.e.
  concrete,               rubber, asphalt).
  concrete recycled tire rubber asphalt)

Keyhole technologies addresses these issues!




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      Coring & Reinstatement Process




 Truck, trailer, portable, or skid-steer mounted coring units cut circular
 holes through the roadway for locate, depth checks, and/or potential
 HDD conflict sites (gas, water, sewer, fiber optic cable etc.).




Remove the core
       Once the core has been cut
       through …
       a core puller is used to
       remove the core;
       The core is set aside (to be
       reinstated later).




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                                                 9/10/2009




Expose Underground Facilities
and Perform Necessary Work




                                Rockville, MD




    A Few Keyhole Activities…

      Daylight in advance of directional
             g
      drilling work
      Pothole/depth check
      Sub-surface utility engineering (SUE)
      Service terminations
      Anode installation (cathodic protection)
      Leak repairs
      New and replacement services
      And more…




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                                                              9/10/2009




 Core Reinstatement
    Backfill & Compact              Bonding Compound




     Core Placement                 Finished Repair




Evaluation of Coring Process
Testing has been performed by several
agencies
  GTI
  Univ. of Illinois
  Golder & Assoc.
  US Army Corps of Engineers



                               S a t shear pu c
                               Slant s ea & punch out tests




    Accelerated loading




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                                                                                9/10/2009




  Evaluation of Coring Process




       Core Reinstated 1995                          Same Core 2003

 “Since the initial reinstatement, more than 145,000 transit buses and more
 than 13 million commercial and other vehicles have passed directly over the
 keyhole with no apparent weakening or other degradation of the reinstated
 core or the adjacent road system or paved surface.”
                                             Golder Associates April 21, 2003




Evaluation of Coring Process




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Evaluation of Coring Process
Restoration of Utility Cut Study
  Collaboration project of North American cities, utility companies and U.S. State
  Departments of Transportation (2000-2005).
  Objective: to develop a guide for best utility cut restoration practice based on
                    principles
  sound engineering principles.
                    Toronto Field Experiment: Observations
 CONVENTIONAL TRANSVERSE TRENCH                              CORED KEYHOLE
  Noticeable failures in conventional cut.        No defects in keyhole cut.
  Conventionally repaired joint between road      Keyhole section established Oct. 2001
  and the cut opened.                             continued to perform well throughout life of
  Visible settlement in trench along wheel        project.
  path.                                           Surface of restored keyhole remained level
  Material used to seal joint lost under action   with the road profile.
  of traffic.                                                                      g
                                                  The Utilibond material surrounding the
  Sand cover at base of trench exposed to         AC/PCC core remained intact (no cracking
  higher than normal levels of moisture           or separation.
  (compared with keyhole).                        Waterproof bond.

“Keyhole construction [is an] effective restoration technique that
should be encouraged whenever feasible to minimize need for
opening large trenches in the future.”
           US Army Corps                                             National Research
           of Engineers                                              Council Canada




Utilities Using Keyhole Technology
    Alagasco                                         Pacific Gas & Electric
    Atlanta Gas & Light                              PECO
    Atmos Energy                                     Philadelphia Gas Works
    Baltimore Gas & Electric                         Questar Gas
    Centerpoint Energy (Houston)                     Sempra Energy
    Centerpoint Energy (Minnegasco)                  Southwest Gas
    City of Des Moines Water Dept.                   UGI Utilities
    Colorado Springs Utilities                       Washington Gas Light
    Connecticut Natural Gas                       Under Review
    Consolidated Edison                             Consumers Energy
                                                    Cinergy (DUKE)
    Enbridge Gas Distribution
                                                    Dominion East Ohio Gas
         gy         p
    Energy East Corporation                         Knoxville Utilities
    Equitable Gas                                   National Fuel Gas
    Keyspan Energy Delivery                         NSTAR
    Las Vegas Valley Water District                 NYSEG
                                                    Oklahoma Natural Gas
    Michcon (DTE)
                                                    People’s Gas
    National Grid                                   South Jersey Gas
    Nicor Gas                                       WE Energies
    Northwest Natural                               Xcel Energies




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                                                          9/10/2009




Potholing for HDD – Cored Openings




    One contractor performing over 2500 cores in 2006
    About 80% are for inspection purposes only




City of Des Moines Water Dept.
    City of Des Moines Water Department
            g y               gy               y
    utilizing Keyhole Technology to cathodically
    protect their water mains
      Coring the pavement
      Using long-handled brazing tool to install anodes
      Result – reduction in cracked mains




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Coring – Win/Win Technology
FOR THE UTILITY/CONTRACTOR
  Saves Time & Money: Permanent repair – no return trips to repave.
  Positive Community Relations: Faster, less intrusive process. Fewer
  complaints from municipalities about traffic disruption, unsightly road cuts,
  sunken patches or weakened or failed roads.
  Improved Logistics: Single crew, one-stop, same-day coring and
  pavement reinstatement means simplified scheduling, no temporary
  patching or repaving and no repeat visits.
  Field-Proven Process: More than 15 years and over 50,000 successful
  corings in tough urban climates.

FOR THE CREW
  Easy to Operate: No extensive training required.
  Easy on the Back: Physically less demanding, no jack-hammers, shovels
  and backhoes. Reduces potential for workplace injury.
  Easy to Use: Just add water, mix and pour.
  Time: Can reopen the road in as little as 30 minutes.




Coring – Win/Win Technology (cont.)
FOR THE COMMUNITY
  Reduced Traffic Disruption: Faster, one-step permanent
  pavement repair means reduced traffic congestion with fewer and
  shorter road closings and no repeat visits.
  Reduced Footprint: Neat, almost invisible 18-inch diameter
  circular core (less than 1/4 the size of conventional road cut) means
  less scarring of the landscape and better pavement performance
  (no corner cracks).
  Environmentally Friendly: No road-cut spoil to be disposed of and
  no temporary patching compounds with volatile organic compounds
  (VOCs) to escape into the atmosphere.
  Cleaner, Safer, Less Intrusive Worksite: No jack-hammers or
  large excavation equipment means less mess during and after
  excavation and reduced disruption for neighbors.




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                                                 9/10/2009




Coring Acceptance/Approvals
Current Status:
  Jurisdictions slow or resistant to accept
  th process of coring and replacement of
  the           f     i    d    l        t f
  the core
  Users of the R.O.W. do not want to embrace
  new technology without approval and/or
  encouragement from jurisdictions
  Change is difficult

   For this excavation and restoration process
   to succeed and make an impact we need
   your help




Questions and Comments?
For more information contact:
   Dennis Jarnecke
   Gas Technology Institute
   847-768-0943
   dennis.jarnecke@gastechnology.org

   Murv Morehead
   City of Overland Park, KS
   913-895-6189
   murvyn.morehead@opkansas.org
   www.opkansas.org
   www opkansas org

   T. Mark Andraka
   PECO Energy Company
   215-841-6485
   mark.andraka@peco-energy.com




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