04/19/231

Cigre WG B1.41 Meeting

Long term performance of soil and backfill of cable systems

Milan, ItalyMar 07 - 08, 2013

Walter Zenger, USA

Convener of WG B1.41

04/19/23Walter Zenger - United States2

Agenda

Introduction

Each member to present their past experience on this subject.

The corresponding members are asked to provide me prior to the meeting with a short write-up of their experience.

Membership including Corresponding members and Young Engineers

Selection of Secretary of WG B1.41

Review of Terms of Reference (ToR) and results of TF B1.41

Approval process of ToR and input by TF members as well as Technical Committee approval

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MembersLast name First name Country Function

Zenger Walter USA Convener

Brakelmann Heiner Germany Member

Burceanu Monica Belgium Member

Chatzipanos Michail Greece Member

De Wild Frank Netherlands Member

Frost David Australia Member-Correspond.

Genovesi Mario Italy Member-Correspond.

Head Julian UK Member

Millar John Finland Member

Moreau Christophe France Member

Douima Youssef France Young Engineer

Oliveira Fabio Brazil Member-Correspond.

Orella Josu Spain Member

Arguelles Jose Manuel Spain Young Engineer

Parmar Deepak Canada Member

Zhang Qunfeng China Member

Thunberg Erik Sweden Member-Correspond.

Bacchini Marco Italy Local Expert & Host of meeting in Milan

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Agenda (cont.)

Discussion of WG procedures

WG B1.41 website and documents

Sign-up as WG expert if not individual Cigre member

Web-based meetings or conference call in between meetings

How to manage the two areas of land and submarine cables

How can corresponding members contribute?

Discuss ToR Scope items 1 to 4 and assign collection of data to WG members including scope of each item and schedule

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Agenda (cont.)

Need to engage SC D1 ?

Annual Report to be presented to SC B1

Determine if WG has to issue a questionnaire or whether we can use questionnaire of WG B1.35.

Next meeting – Date & Host

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Main Goals of WG B1.41

Determine the long term performance of soil and backfillUnderstand the parameters that can impact the change in properties over time

Draw on existing knowledge of heat flow, soil and backfill properties and short term soil and backfill stability

For existing systems – primary focus

New installed systems

Impact of increased loading

Long-term changes in environmental conditions

Evaluate historic development of backfill engineering

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Scope of WG B1.41

1. To review the literature (experience, history) on the subjectCigre and IECJicable, IEEE, EPRI, Kema, Ontario Hydro & HQ, CEGB, ERA, IET, Heiner B, EDF, Canadian

Soils database, NZ Gov report,Other

2. To establish the appropriate terminology and characterization parameters.3. To review methods to measure the thermal, mechanical and chemical soil / backfill properties and stability.

IEEE, ASTM, DIN EN 12390-2, BS EN 12390-2, nuclear density gauge (ASTM) Troxler, BS/IEC 60692, TPA and related methods, Soil stability measurements.

4. To review methods to measure the aging and long-term stability of soil and backfill properties over system life

5. To review technical methods how to mitigate deterioration of soil and backfill conditions including moisture depletion by vegetation or other utilities

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Scope of WG B1.41 ( cont. )

6. To evaluate the consequences, if no action is taken, such as loss of ampacity, including cost and overheating of the cable system.

7. To integrate the information in a practical users guide.

8. To apply to extruded, paper, and paper-laminate cable systems

9. To apply to HV AC and DC land cable systems including direct buried, direct buried ducts or pipe, duct bank / manhole systems, and Horizontal Directional Drill (HDD) installations

10. To apply to HV AC and DC submarine cable systems including ploughing, jetting, trenching and HDD installations

11. To apply to MV AC cable systems of high importance

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Terms

Thermal resistivityThermal diffusivityThermal stability / thermal runaway

TPA - Thermal Property AnalyzerEarth Interface TemperatureControlled dry-out / critical temperature / critical radiusHeat fluxTime to dry-out

Ambient Earth Temperature and it’s change over timePhysical Parameters

GeometrySoil type / Composition / TextureMoisture content / Critical moisture content / Saturation Index / Moisture capacitanceDegree of compactionSoil densityPorosity

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Terms

Installation Parameters Depth of burial – change over timeType of cover – vegetation, streets, structures

Installation MethodsType of installation – trenching, plowing – cable or duct, HDD Cable configuration – direct buried, duct, duct bank, HDDBackfill – Native / thermal sands / FTB / grouting Casings and HDD, ducts grouted or water filledForced cooling systemsSubmarine environment

Test methodsApplicable standards and publicationsTest setupsSamplingField thermal survey – in-situ testing

Aging or change over timePhysical changes – Geometry, moisture content, compaction, porosity, densityChemical changes

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Other Issues

QuestionnaireUse results of WG B1.35 questionnaire?Issue WG B1.41 questionnaire?

Annual Report to SC B1

Next meeting Date July 9 / 10Host Prysmian UK, EastleighWebcast necessary ? Date