1. 9/4/20151 Cigre WG B1.41 Meeting Long term performance of soil and backfill of cable systems Milan, Italy Mar 07 - 08, 2013 Walter Zenger, USA Convener of WG B1.41

2. 9/4/2015Walter 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

3. 9/4/2015Walter Zenger - United States3 Members

4. 9/4/2015Walter Zenger - United States4 Agenda (cont.) Discussion of WG procedures WG B1.41 website and documentswebsite Sign-up as WG expert if not individual Cigre memberexpert 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

5. 9/4/2015Walter Zenger - United States5 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

6. 9/4/2015Walter Zenger - United States6 Main Goals of WG B1.41 Determine the long term performance of soil and backfill Understand 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

7. 9/4/2015Walter Zenger - United States7 Scope of WG B1.41 1. To review the literature (experience, history) on the subject Cigre and IEC Jicable, IEEE, EPRI, Kema, Ontario Hydro & HQ, CEGB, ERA, IET, Heiner B, EDF, Canadian Soils database, NZ Gov report, Other Cigre 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

8. 9/4/2015Walter Zenger - United States8 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

9. 9/4/2015Walter Zenger - United States9 Terms Thermal resistivity Thermal diffusivity Thermal stability / thermal runaway TPA - Thermal Property Analyzer Earth Interface Temperature Controlled dry-out / critical temperature / critical radius Heat flux Time to dry-out Ambient Earth Temperature and it’s change over time Physical Parameters Geometry Soil type / Composition / Texture Moisture content / Critical moisture content / Saturation Index / Moisture capacitance Degree of compaction Soil density Porosity

10. 9/4/2015Walter Zenger - United States10 Terms Installation Parameters Depth of burial – change over time Type of cover – vegetation, streets, structures Installation Methods Type of installation – trenching, plowing – cable or duct, HDD Cable configuration – direct buried, duct, duct bank, HDD Backfill – Native / thermal sands / FTB / grouting Casings and HDD, ducts grouted or water filled Forced cooling systems Submarine environment Test methods Applicable standards and publications Test setups Sampling Field thermal survey – in-situ testing Aging or change over time Physical changes – Geometry, moisture content, compaction, porosity, density Chemical changes

11. 9/4/2015Walter Zenger - United States11 Other Issues Questionnaire Use results of WG B1.35 questionnaire? Issue WG B1.41 questionnaire? Annual Report to SC B1 Next meeting Date July 9 / 10 Host Prysmian UK, Eastleigh Webcast necessary ? Date