design considerations for successful on-grade & technically complex hdd … · 2015. 4. 20. ·...
TRANSCRIPT
Earth Boring Co. Limited – 1576 Ifield Road Mississauga, ON L5H 3W1(905) 277-9632 fax (905) 274-9040
Design Considerations for Design Considerations for Successful OnSuccessful On--Grade & Technically Grade & Technically
Complex HDD InstallationsComplex HDD Installations
Gene WoodbridgeEarth Boring Co. Limitedwww.earthboring.ca
Trenchless Since 1947
Geo-Technical ReportDesign TeamROWTechnologyEnvironmentHDD ContractorTimingSocial Consideration
Complex Installations
How important is the grade/slope on the installation
Where in the system can we achieve more grade?
1% Ideal in HDD installations
Trenchless Since 1947
Directional DrillingSurface launched, electronically guided, steerable (depth-roll-pitch), bore
Trenchless Since 1947
Directional Drillingwater services towater transmission pipeline, tremendous success with gravity sewers and other grade specific projects, gas, hydro, etc
Pilot bore created along predetermined bore path with 1.5m to 10m drill rods (drill string)A reamer is used to enlarge the bore pathOnce the hole is enlarged (25% to 50% larger than product pipe) the product pipe is pulled into the bore hole
Trenchless Since 1947
Risk MitigationRisk MitigationWhat is risk mitigation?
When do you perform risk analysis?What are the inputs to your risk
identification?
Why Risk Mitigation?
TimeCost
Quality
Just get the pipe in the ground..
v.s.
Where do you stand?
Responsible Design Shares
the Risk – It does not
download it
Who is the Expert?The Project Team
Trenchless Since 1947
The Soils Report / Geotechnical Report
Critical to the success of trenchless projectsKey to the selection of the trenchless methodPlanning here – saves money later onGround conditions can limit any construction workTake time with your Trenchless contractor to understand the implicationsKnow your water table – less concern hereGood Design & Good Trenchless Estimate
is Predicated on the Soils Report
Trenchless Since 1947
The Soils Report cont’d
Utilized as a guide and is used in conjunction with field experience and understanding of the complete geo-technical report
Trenchless Since 1947
Bore Holes…How many are enough???
Trenchless Since 1947
Soils and On-Grade HDD
Boulders
Cobble
Present challenge but acheivable – consideration to design grade and acceptable field results
Significant challenges – fine grades not achievable
Easy Hard
Trenchless Since 1947
Soils and On-Grade HDD
Soft / Cohesionless Soils
Require mud program to ensure adequate soils preparation
Adjust gradeAdjust alignment – Sunnybrook Park
Challenging Soils – What are the Options?
Trenchless Since 1947
DesignProminent
Often critical aspects of dwg are split over pages
Overlay Soils InformationSee beyond the page
On site conditions, obstructions, obvious limitations
Straight line installationsCurve in open cut
Detailed and Well Reviewed SpecificationsHDD Can not end at a MH
Trenchless Since 1947
Design - Dwg
Soil Report Elements on DwgContiguousStraight line azimuth
curve in o/cChainages and ElevationGrade/SlopeDetails of obstructionsFrac Mitigation
Trenchless Since 1947
Design - Dwg
Trenchless Since 1947
Design - SpecificationsDetailedWell ReviewedAvoid the temptation to copy and paste
RedundantRequest the same information in various sub specs
Erroneous, out of place specs (daylight pilot bore)
Realistic, practical, warrantedThis is not the section to learn about HDD or about the capabilities of the HDD Contractor
Relevant, Relevant, RelevantThe 3 ‘R’s of Specifications
Don’t leave it to the contractor to develop your specification
Trenchless Since 1947
Design – Specifications “Really?”Daylight the pilot bore to confirm location
Artificial Fracture point for the reaming & pullbackAlready asking for as-built and pilot bore data
4” Variance Azimuth and HorizonIs this realistic on a 750mm Installation?Spec requires CA to be notified… 4”… 100mm…Is this required in an open cut?
Video inspection of watermain installationDo you know what cameras are predominately used to inspect? How much chlorine will it take…
If restraints are required, clearly indicate
Trenchless Since 1947
ROW - Right of WayEquipment Set-Up
HDD RigMud ManagementSet-Back Room
Drill stem tracking –Walkover, Wire, LoopsPipe Staging
FusionPullback – Tail TrenchStorage
Frac ManagementWell InstallationEquipment Staging
Road Closure Permits / Traffic Control
Trenchless Since 1947
ROW - Limited
Trenchless Since 1947
ROW - Pipe Staging
Bayview
Receiving Shaft
Trenchless Since 1947
ROW – Fortunately….
Trenchless Since 1947
ROW – 750mm HDPE Stouffville Rd
Trenchless Since 1947
ROW – Why Do You Need All that Room?
HDPE – Requires Relax TimeAggravated Bend at Installation point
Forces on the pipe and overall installation forcesDevelop and ensure better grade Space saves time later on…
v.s.FORCE
FORCEInstallation forces are
directed along the installation with proper lay down – pipe
is off grade in ‘jammed’installations
Trenchless Since 1947
HDD Contractor
ReputableReliableExperiencedPre-Qualification
Elements Relevant to the work proposedEngage early
Time of design conceptualization
Validate the criteria – don’t assume
Trenchless Since 1947
HDD Contractor – Pre-Qualification
Selection of Previous WorksRelevant to the works required
On-Grade v.s. Forcemain
Details of the work completedContact Information of Owner/Consultant/ContractorSignificant highlights of the work
Trenchless Since 1947
Technology
Commensurate with the workSimple Load Calculations
Weight of pipe v.s. Pullback Capacity of HDD RigMud Mixing and Recycling PlantSurvey Electronics Relevant to the Work
Wireline vs Walkover vs AC/DC Grid –Accelerometers / Magnetometers
Trenchless Since 1947
Environment
Soils Report Figures hereROW considerationsStaging
Conservation PermittingCold/Warm water time windows
Access Restrictions – Wasaga BeachTiming WindowsEnvironmental Contingency Plans
Trenchless Since 1947
Directional Drilling (Environmental Consideration)
Responsible ContractingEnvironmental MitigationFrac Mitigation -
Wells, Mud Management Plan, Poly Swell, ViscositySilt Curtains
Coir LogsSand / Pea Gravel BagsSilt FenceDepot SuppliesWritten ProgramEnvironmental PolicyEnvironmental Consultant
Trenchless Since 1947
Environment
Trenchless Since 1947
Bronte Creek 750mm - 2006
Trenchless Since 1947
Timing
Varies by JobComplexity of GradeGround ConditionsProduct DiameterROW
SpecificationsQVE
Trenchless Since 1947
Social Considerations
Local PoliticsRecent Construction Activities – King CityCommunity Awareness / ActivismConstruction ImpactHeritage Location
St. Andrews College (Gates)Fort York
Trenchless Since 1947
Complex Installations
Geo-Technical Report
ROW
Technology
Social ConsiderationTiming
HDD Contractor
EnvironmentDesign
Success
Time Cost
Quality
Designers DesignContractors Install
Everyone Collaborates!
Trenchless Since 1947
Final Thought
Well Designed Projects are Easier to Construct
And thereby more cost effective
Earth Boring Co. Limited – 1576 Ifield Road Mississauga, ON L5H 3W1(905) 277-9632 fax (905) 274-9040
Gene WoodbridgeEarth Boring Co. Ltd.www.earthboring.ca
(905) 277-9632