UTILITY RELOCATION DESIGN CONSIDERATIONS Presented by Bryan Slone, PE PLS August 16, 2017
INTRODUCTIONS n Objective of presentation n Disclaimer n Clarification: Distribution vs Transmission n Per DOT 192. 3 – Transmission line means a pipeline, other than a gathering line, that: (1) transports gas from a gathering line or storage facility to a gas distribution center, storage facility, or large volume customer that is not downstream from a gas distribution center; (2) operates at a hoop stress of 20 percent or more of SMYS; or (3) transports gas within a storage field. Distribution line means a pipeline other than a gathering or transmission line.
WHERE IS THIS LOCATED?
True or False? n n Buried utilities are often located between curb & sidewalk. A KDOH Type B Curb Box Inlet (CBI) provides the most available room between curb & walk. n True – the junction chamber for a Type B CBI is located from the curb line out into the road thereby freeing-up space behind the curb for utilities. The KYTC Permits Manual regarding encasement requires that all buried gas pipeline crossings greater than 2” in diameter be encased. n False – PE-304 of the Permits Manual lists scenarios where the need for encasement is excepted so long as certain requirements are met.
True or False? n n As-Built relocation drawings provided by a utility company are an adequate source of information for a roadway contractor to proceed with excavation around said utility without having to call in locates. n False – excavators are required by law (KRS 367. 4901) to adhere to all requirements of the state’s dig law. The ratio of an igloo’s circumference to its diameter is: n An Eskimo Pi
ASSUMPTIONS n n Assessment has revealed there is conflict: Direct n n Indirect: n n Subgrade cut, embankment benching, storm or sanitary sewers/structures, retaining wall, signal/light pole foundations Insufficient or excessive cover, inaccessible, proximity to adjacent trenching or structures, etc. Concluded you need to maintain the facility
WHAT TO DO… ? n “Negotiate” with KDOT & their design engineer or general contractor to revise plans to alleviate conflict… if possible
CONSIDERATIONS n Possible design revisions to minimize or eliminate conflicts n n n n Storm & drainage structures Sanitary sewers & structures Elliptical pipe vs. round Embankment benching Traffic signal & light pole foundations Back slopes on side ditches Driveway approaches
PRELIMINARY RELOCATION DESIGN n Consider betterment & growth potential n n Consider alternate feeds or uprates n n any pending New Business line extensions consolidation of mains Consult with related departments n Corrosion concerns n n Cathodically protected - anodes or rectified Subject to liquids n need to add or maintain a drip
PRELIMINARY RELOCATION DESIGN n Typical Sections n n Pavement Sections n n Reserved Undercut Cross Sections n n Underdrains Embankment Benching Ditching Traffic Signalization Plans Detour/Diversion Plans & Alternates
PRELIMINARY RELOCATION DESIGN n n Coordinate relocations with other involved utilities “Rough Stake” followed by field review n n n what might look good on paper doesn’t always work! Demolition of existing structures Construction Methods n Open trenching vs. directional boring
PRELIMINARY RELOCATION DESIGN n Clearances [GS 3010. 080] n n n R/W Issues n n n State roads vs. county roads Condemnation Contaminated soils known or suspected n n Between other utilities and structures Trench boxes Monitoring wells? Blasting [GS 1100. 020] n Assess using Pipe. BLAST program w/Data Sheet
FINAL RELOCATION DESIGN n KDOT approval of casing requirements, or waiver thereof, & backfill material. n n n Conform to federal/state/local codes Environmental Permitting [HSE 4440. 010] n n Consult KDOT Utilities & Permits Manuals NOI and/or SWPPP required Project Environmental Information Form (PEIF) CKY = Tiffany Fritchley (Ph. 614 -481 -1302) Distribute proposed relocation plans to KDOT and other involved parties.
TYPICAL PIPE MATERIALS n Polyethylene (PE) Plastic (Up to 100 Year Lifespan) Stick Pipe Coil Pipe
TYPICAL PIPE MATERIALS n Medium Density High Density
TYPICAL PIPE MATERIALS n Carbon Steel (Up to 100 Year Lifespan if Cathodically Protected) Typically Epoxy Coated or Powercrete for Boring Installation
CATHODIC PROTECTION n Used on steel pipe and components to extend the lifespan of the facility by slowing rate of corrosion. n Typically sacrificial [magnesium] anodes tack welded to steel pipe or use an induced [low] current system. n n n Mg anodes come in various sizes (3 lb, 9 lb, or 17 lb). Anodes are placed in the ditch away from the pipe. Rectified systems require AC power source and room for either a vertical or horizontal anode ground bed. n n n Horizontal bed can require a large footprint (30’ X 200’) Vertical [drilled] ground beds more common these days and require less of a footprint to construct & operate (20’ X 20’). Stray current from adjacent high voltage OHE can adversely effect the CP on buried pipelines and above ground appurtenances requiring the addition of zinc ribbon and/or mats to draw stray current off of the gas facilities.
LOCATE MARKER BALLS: What, When, Why n Used in conjunction with a compatible locator, it can transmit an RF signal to the buried marker ball which is reflected back to the locator indicating the location of the ball by a visual meter and audible tone. Per GS 3010. 050:
COMMON APPURTENANCES 1 st Cut Regulation used when customer is served directly off of HP main
COMMON APPURTENANCES n Regulator Stations (a. k. a. : Pressure Reducing Stations) Conventional Build Skid Mounted
COMMON APPURTENANCES n Measuring Stations (a. k. a. : Meter Settings) LG Volume-LP Residential LG Volume-Elev Press
COMMON APPURTENANCES n Heaters – to counter gas temp drop due to pressure differential Water Bath Heater Dry Line Heater
TYPICAL TIE-INS n Plastic Tie-Ins 4” PE Plastic w/By-Pass Operable Same Pipe After Being Tied-In
TYPICAL TIE-INS n Steel Tie-Ins 12” HP Steel w/SPH Control Fittings Same Pipe After Tie-Ins Completed