1. 4 mai 2015 New Gas Works Concepts: The examples of minimal trenching Franck Groeschl ( DVGW – Bonn) - Hartmut Reichenbach (S&P - Stuttgart) Jean-Pierre Capdevielle ( Gaz de France – Saint Denis)

2. Diapo 219/04/2007 2 Improve the safety of gas networks Facilitate identification of existing structures Improve passive protection of networks Limit the impact of works for neighbours Hindrance to traffic (car and pedestrians) Works duration - Reduce the environmental impact Reduce the environmental impact Reduction in volumes of waste Reduction in borrow quantities Improve economic efficiency Direct cost during laying Indirect cost, reducing risks to third parties Improve safety and quality of urban works: with a global approach to the works function

3. Diapo 319/04/2007 3 Consideration of the site typology Optimisation of the trench geometry Suburban or rural Few traffic constraints Possibility of bringing in large construction machinery Few obstacles in the soil Urban environment High traffic density Construction machinery adapted to town centres Large number of obstacles in the soil (particularly under the pavement) Laying at shallow depth (Gaz de France /ETDE project) Placement in narrow trench with recycling of material (DVGW / Gaz de France project)

4. Diapo 419/04/2007 4 Minimal intrusion into roadways while ensuring optimum quality and reduction of costs Aim of the research project «Minimal Trenching »: Determine the construction methods for minimal intrusion Optimise quality assurance for street works and pipe laying Professional guideline with a view to harmonisation of French-German standards

5. Diapo 519/04/2007 5 Essential aspects of the research project Comparison of guide lines and required performances in France and in Germany

6. Diapo 619/04/2007 6 Essential aspects of the research project Treatment of excavated soils for re-employment as backfill material

7. Diapo 719/04/2007 7 Essential aspects of the research project Long term study of the behaviour of recycled materials Study of the « re-excavability »

8. Diapo 819/04/2007 8 Essential aspects of the research project Quality control ( Q.C)

9. Diapo 919/04/2007 9 Facilitate laying conditions in suburban environment Definition of technical-economic recycling conditions Narrow trench site – depth according to regulation Study of self compacting materials based on recycled excavated materials (Germany)

10. Diapo 1019/04/2007 10 Facilitate laying conditions in urban environment with new self-compacting concrete in shallow trenches PATENTED WITH ETDE

11. Diapo 1119/04/2007 11 A technique in service already tested internationally (Switzerland, U.K.) 1 km done in narrow trench – 50 cm deep « Just-in-time & short » site minimising nuisance to neighbours Reopen for traffic at the end of the day

12. Diapo 1219/04/2007 12 Knowledge of the soil before the work GIGA and ORFEUS : Two european projects with PCRD to federate the best skills Objectives: to characterise the performances of existing radar systems and develop new systems capable of satisfying user needs

13. Diapo 1319/04/2007 13 Tests in controlled environment An environment adapted to performance tests  20 to 160 mm diameter tubes (PE, steel, cast iron)  20 cm to 2 meters deep (positioned with precision)  4 different types of soil (sand, earth, clay-lime, fill)  2 surface types (coated chippings,soil) Knowledge of the soil before the work GIGA and ORFEUS : Two european projects with PCRD to federate the best skills

14. Diapo 1419/04/2007 14 Conclusions with these 3 R&D GERG Projects : Placement in narrow trench with recycling of material Laying at shallow depth with new self compacting concretes Optimised GPR to find every distribution networks under the streets Opportunities to use, in Europe, new technologies with evolutions of laying rules for the distribution gas pipes + +