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