Sustainable Utility Construction: Methods and Techniques

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1 Sustainable Utility Construction: Methods and Techniques September 19, 2011 APWA Congress Denver, Colorado Murv Morehead ROW Coordinator Overland Park, Kansas Monty Zimmerman Row Manager Lenexa, Kansas Sustainability Is In Public Works, best encapsulated in the phrase everything we do with an eye to the future. Essentially this means designing and constructing infrastructure that will not become a cost or maintenance burden to future generations and at the same time being mindful of the fact that the resources we need today must also be available for those to come after us. Sustainable infrastructure is the development of water, sewer, roads and other infrastructure systems that meet the needs of current and future generations in a socially, economically and environmentally sustainable manner. 1

2 Why Should The Sustainability of Our Rights-of Way Be of Concern Today? This Is NOT Sustainable For The Future Nor Is This 2

3 Or This The Concern Is Sustainability/viability of the physical property that makes up our Rights of Way. Overcrowding from new buried facilities without removing abandoned plant or implementing organized utility corridors will eventually render our ROW unmanageable and unable to meet demands of future generations. Removal Of Abandoned Facilities Not a popular subject The elephant in the room Generally not enforced although it is a requirement in some ROW mgmt. ordinances If our ROW is to remain viable for future generations, abandoned facility removal MUST be addressed Some lines may be re-purposed (i.e. fiber optic cable in abandoned gas line) Greatest challenge is managing abandoned lines (abandoned vs. live) 3

4 Removal Of Abandoned Facilities Utility corridors should be considered critical for any new development but are not feasible for existing infrastructure. Removal of abandoned facilities is also becoming a critical issue but is costly and not currently pursued by facility or ROW owners. Why Remove Abandoned Facilities? Abandoned facilities complicate repair of viable facilities Physical size of abandoned line renders that amount of ROW unavailable for future installations Abandoned lines/cables cause increasing confusion during locating activities Current practice is remove when encountered Removal of Abandoned Facilities Until abandoned facility removal is adopted as a BMP, coupled with the inescapable fact that our ROW s are becoming over congested, we must embrace construction methods that will allow us to work within the physical constraints we find ourselves in. One very important alternative at our disposal is Trenchless Technologies 4

5 Why Use Trenchless Technology? To prevent this: 4 lane thoroughfare reduced to two lanes of traffic Why Use Trenchless Technology? And this Even though street is repaired properly it is still a patch Why Use Trenchless Technology? In favor of this Service Line connections 5

6 Last But Not Least Contractor SAFETY and SAFETY of the Public Some of The Most Common Trenchless Methods Are: Auger Boring used for casing installations Pipe Bursting used for pipe replacement Slip Lining - used for pipe replacement Horizontal Directional Drilling and Pneumatic Piercing Tools used for pipe and cable installations of all types and sizes CIPP (Cured in Place Pipe) 6

7 Auger Boring Used primarily for road crossings Pipe Bursting Pipe Bursting has been used primarily to replace water lines Methods vary but operation used in OP employed a winch assisted/pneumatic powered bursting head pulling in HDPE butt-fused pipe Open street cuts still necessary to install Tee s and valves Pipe Bursting 7

8 Pipe Bursting Slip Lining New method of water line replacement Made possible due to opportunity to downsize pipe (HDPE provides smoother flow characteristics) 1,350 8 diameter HDPE pipe pulled in place in just over 4 hours As with pipe bursting, open street cuts are still necessary The Pipe String 8

9 Slip Lining in Progress HDPE being pulled into host pipe HDD and Missiles Horizontal Directional Drilling (HDD) and Pneumatic Piercing Tools (Missiles) are by far the most predominant methods of trenchless technology. Both processes lend themselves very well to installation of coax, copper and fiber optic cables. HDD is fast gaining acceptance for installation of gas and water lines as well. The HDD Operation Bore out to termination point Typical bore length is 500 ft. Pre-ream if needed to increase bore diameter Mixing (removes soil) vs. compaction (displaces soil) reamer Problems can arise if this step is neglected Pull back product 9

10 The Drill The Reamer Product Pullback 10

11 Product Pullback The Missile Operation Rectangular pits dug approximately 20 apart Pneumatically powered non-steerable missile is lowered into pit and through percussive effect moves through the soil to exit into the next pit Conduit/cable is then manually pulled through newly created tunnel The Missile 11

12 Missile Operation Not a pretty sight Vacuum Excavation Is critical to trenchless technologies Is ideally suited for locating existing buried utilities prior to trenchless construction activities Is far less intrusive than open cut excavations Is the perfect complement to the Keyhole/Coring/Reinstatement process Damage to existing utilities is virtually eliminated Vacuum Excavation 12

13 CIPP (Cured in Place Pipe) Method to rehabilitate existing pipe s internal functionality without total pipe replacement Uncured material is introduced into host pipe; material is then inflated until contact is made with entire inside diameter of host pipe. New material is cured with steam or hot water. CIPP (Cured in Place Pipe) Before CIPP (Cured in Place Pipe) Material ready for installation 13

14 CIPP Curing Process CIPP (Cured in Place Pipe) After Additional Trenchless Methods Pipe Reaming - a system that was developed to utilize a directional drilling unit, specialized tooling and techniques to grind and remove the existing pipe as the replacement is pulled into place. Pipe reaming offers an alternative to abandoned facility removal. 14

15 Pipe Reaming Pipe Reaming Arrowbore Arrowbore Patented Horizontal Directional Drilling Construction Method Technology that allows very precise line and grade control for installations of gravity flow lines Because Arrowbore uses HDD as the primary construction technique, surface disturbance is substantially reduced when compared to traditional open trench sewer installations 15

16 Arrowbore Vertical Casing Installation Arrowbore the Key to On Grade Installation Arrowbore Process 16

17 Cost Comparison Open Excavation Fuel Consumption Verses The Patented ArrowBore Method Green Solutions for Today s Environment Excavate and install 15 foot deep, with backfill only ArrowBore and install 15 foot deep "This doesn't include the cost of restoration". "90% less restoration" Gallons per day Gallons per day 125 Excavator #1 5 Vertical drilling rig 100 Excavator #2 10 Horizontal drilling rig 50 Front end loader 3 Mini Excavator 10 Uni Loader 4 Fluid mixing system 40 Two dump trucks 5 Portable vacuum 15 Misc. Pumps, generators, ect. 15 Truck vacuum 1/2 day 20 Pickup trucks 15 Pickup trucks 0 Dewatering System 0 0 Setting up the dewatering system Total gallon per day 57 Total gallon per day $3.00 Diesel fuel price per gallon $3.00 Diesel fuel price per gallon $5, Fuel cost per week $ Fuel cost per week 36 Weeks per year (9months) 36 Weeks per year (9months) $194, Fuel cost per crew per year $30, Fuel cost per crew per year FUEL SAVING PER YEAR PER CREW $163, Open Cut Crew $110, Restroation Crew $243, Total Savings All Trenchless Methods Are Intended to Get Us from This.. Or This 17

18 To This.. Arrow Bore installation Locating Utilities Underground utilities can be located using this method Locating Utilities Unfortunately, there are many utility lines under pavement that need to be visually located prior to any trenchless activity and to avoid this 18

19 Keyhole, Coring and Reinstatement Process This process involves core drilling through pavement cross section then using vacuum excavation to remove sub grade material until utility in question is found. Sub grade is then replaced and previously removed core is bonded back into place providing a waterproof virtually invisible repair. Keyhole/Coring/Reinstatement As can the vacuum unit Core drills can be small or large The Keyhole process Keyholing can not only be used for utility exploration investigations but for utility repairs as well. Long handled tooling has been developed that allows certain types of repair work to be accomplished while on the street surface 19

20 Repairs Being Made Through Keyhole Core Reinstatement Backfill & Compact Bonding Compound Core Placement Finished Repair The Finished Product 20

21 Coring-Keyhole Process Which would you prefer on your streets? Sustainability Benefits from Trenchless Technology Significantly reduced surface disturbance therefore significantly reduced restoration costs Significant reduction of inputs needed (i.e. fuel, asphalt, pieces of equipment, manpower, etc.) Significant reduction in traffic impact Significant overall reduction in carbon footprint of project Many methods require little or no additional ROW to be used Sustainable Construction Techniques (Concepts) for Utility Installations Shared Trench Common Trench BDN (Buried Duct Network) Nojitech Duct Banks 21

22 Why use these methods? To Avoid This Or This 22

23 Or This Shared Trench Two or more utilities agree to construct their facilities in the same excavated trench. This agreement saves all utilities who participate; Construction cost including restoration cost Reduces carbon footprint Reduces the area of right of way used Shared Trench 23

24 Shared Trench Common Trench Semi-Engineered trench in which two or more utilities agree to co-locate in the same trench. Locations within the trench are established based on clearances and depths that each utility requires. Common Trench 24

25 Common Trench A Different type of Shared Trench BDN (Buried Duct Networks) BDN s overlay a minimum number of empty ducts on top of or next to direct buried cables for future expansion or replacement of damaged direct buried cables. Can be used by one utility operator or as extra space for future providers. The BDN can hold from 2 to 8 ducts ranging in size from 2 to 6. 25

26 BDN (Buried Duct Networks) BDN (Buried Duct Network) BDN Installation Over Existing Utilities 26

27 BDN Installation Along Side Communications Project Nojitech Raceway System Multiple square sectioned PVC tubes placed in an outer casing that is either fire proof or has high weight tolerance. Connection design is simple, requiring four bolts to secure sections. Designed for quick and safe installation saving time and money. Nojitech Raceway System Spider Series 27

28 Nojitech Raceway System Spider Series Nojitech Raceway System Gopher Series Nojitech Raceway System 28

29 Duct Banks Engineered with input from all existing utilities in the area where the duct bank will be constructed. Can be designed for any number or combination of compatible utilities. Installation cost can be shared in a number of ways to facilitate participation in the duct bank. Duct Banks Each utilities' cost is proportional to the size and amount of ducts they require. How are cost savings attained: One trench One contractor doing construction One location for all utilities One restoration effort Japan s Concrete Box Tunnel 29

30 European Duct Tunnel Open Trench Installed Communications and Electric Power Duct Bank Duct Bank for Ontario Highway Project 30

31 Lenexa Duct Banks Lenexa has been incorporating duct banks with some road projects since 1998 The construction of these duct banks has changed 4 times over the last 13 years The change of design was the result of more cooperation with the utility companies. New design characteristics will be added to future duct bank projects. Duct Bank 3 rd Generation Duct Bank Prairie Star Parkway 31

32 87 th Street Duct Bank Road project the first phase of a 240 acre mixed use development project. Project took two years to design. City and design engineering firm meet with each utility 7 to 10 times during design to layout duct bank locations. New Road Alignment 87 th Street Duct Bank Configuration 32

33 87 th Street Duct Bank Vault Location #3 87 th Street Duct Bank Vault location #1 Duct Bank 87 th Street 33

34 Duct Bank 87 th Street Duct Bank 87 th Street Duct Bank 87 th Street 34

35 Duct Bank 87 th Street Intersection Connections 87 th Street Intersection Sweeps Manhole Placement 35

36 Hand Holes and Vaults 87 th Street Power Manhole Power Manholes 36

37 Power Duct and Manhole Power Duct Bank Questions? 37

38 Murv Morehead City of Overland Park Monty Zimmerman City of Lenexa 38