22 avril 2023
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)
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
Diapo 319/04/2007 3
Consideration of the site typology Optimisation of the trench geometry
Suburban or ruralSuburban or rural• Few traffic constraints• Possibility of bringing in large construction
machinery• Few obstacles in the soil
Urban environment 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)
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
Diapo 519/04/2007 5
Essential aspects of the research project
Comparison of guide lines and required performances in France and in Germany
Diapo 619/04/2007 6
Essential aspects of the research project
Treatment of excavated soils for re-employment as backfill material
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 »
Diapo 819/04/2007 8
Essential aspects of the research project
Quality control ( Q.C)
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)
Diapo 1019/04/2007 10
Facilitate laying conditions in urban environmentwith new self-compacting concrete in shallow trenches
PATENTED WITH ETDEPATENTED WITH ETDE
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 neighboursReopen for traffic at the end of the day
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
AIR DEFENCE
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
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
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