1. Future Circular Collider ARUP: Status of Geological Models Yung Loo Andy Kervell

2. Contents Scope of Work and Work Stages
Preliminary Geological Studies and Decision Aid Tool
Preliminary findings and constraints
Geological Studies – Next Stages
Decision Aid Tool (GIS) – Next Stages
Proof of Concepts and Project examples
Discussion on requirements, constraints, opportunities to collaborate.
Next steps (+ furthered in afternoon session)

3. Work Stages

4. Preliminary Geological Studies | Decision Aid Tool
A. Key Variables:
Tunnel Elevation
Tunnel Gradient & Inflection Point
Shaft Position on Ring
B. Key Outputs:
Summary statistics:
Shaft depth +uncertainty
C. Accessible Interface
100km
(230mASL)
100km (310mASL)
Gradient, %
0.5
0.1
Mean Shaft Depth, m
240
224
Max Shaft Depth, m
609
619
Mean total length of all shafts, km
2.21
2.05
Molasse:Limestone:Moraine
(Dependent on NW Jura/Molasse contact)
80:20:0 to
(72:28:0)
75:20:5
(67:28:5)

5. Preliminary Geological Studies | Decision Aid Tool
0km to 10km
Molasse / Moraine interface drops steeply to the north of Latitude ~46.27 (~North of Corsier)
To avoid tunnelling through the moraine under Lake Geneva, the ring needs to pass:
South of Latitude ~46.27
Below ~250mASL.
Tunnel through moraine? Lake sediment rockhead?
EPBM? / Slurry TBM? / Immersed Tube (IMT)?
[seismic survey carried out by Fiore (2011)]

6. Preliminary Geological Studies | Decision Aid Tool
10km to 45km
Tunnel enters pre-alpine thrust front
Transition from Geneva Basin Molasse to overthrusted pre-alpine molasse and flysch
Subsurface contact is not expected to be clearly defined.
Faulting and Cretaceous basement extent to be determined
Tunnel engineering geology broadly similar across molasse sequences
La rivière de l’Arve at Chainage 25km will be underlain by moraine. It is not expected to clash with a graded alignment.

7. Preliminary Geological Studies | Decision Aid Tool
45km to 75km
Tunnel intersects foothills of Southern Saleve and foothills of Vuache, bordering the molasse
Two main molasse sections underlie Les Usses and La Rhone. (peak of a graded alignment)
Connectivity with rivers, underground solution features, uncompacted superficials
Definition of rockhead level important here

8. Preliminary Geological Studies | Decision Aid Tool
75km to 100km
Tunnel contacts between the foothills of the Jura and the Molasse Basin.
Tunnelling through sedimentary sequences may be unavoidable, unless whole alignment moved SE.
Better definition of rockhead contact needed.

9. Preliminary Geological Studies | Decision Aid Tool
Summary: Areas to Focus
Moraine/molasse boundary beneath Les Usses and La Rhone
Jura limestone/molasse boundary at the Northwest part of the ring
Lateral extent of subsurface limestone/sedimentary sequences at the Southern Saleve and Vuache
Further geological investigation, particularly of the sub-alpine molasse/flysch to cover: Effects of faulting, other geohazards and engineering geological features specific to the various sequences.

10. Geological Studies – Next Stages
St-Claude
Douvaine
St-Julien-en
Genevois
Annemasse
Annecy
Bonneville
Seyssel

11. Geological Studies – Next Stages
e.g.
Annemasse: Mapped Molasse-Quaternary Contact
Annecy-Bonneville: Mapped cross-section on Saleve
BRGM: Carte Geologique de la France a 1/50 000, no. 654
BRGM: Carte Geologique de la France a 1/50 000, no. 678

12. Next Stages Constraints Geometric Circumferencial variation
Ring shape e.g. quasi-circular, quasi-racetrack
Planarity
No. of shafts and spacing
Geological
Rockhead contacts: Quaternary | Molasse | Cretaceous
Geohazards: Faults, expansive soils, aquifers, stress, caves

13. Decision Aid Tool (GIS) – Next Stages
Geometric Attributes
Geotechnical Attributes
CERN: 80km Ring Concept
Shieldhall Tunnel
ArcGIS Platform Gaming Engine Based Geological Models
Combined Attributes
+ Outputs

14. Decision Aid Tool (GIS) – Next Stages
Preliminary Proof of Concept

15. Decision Aid Tool (GIS) – Next Stages

18. Available Data http://infoterre.brgm.fr/viewerlite/MainTileForward.do
Existing Investigations:
Annemasse – Isohypses du contact Molasse/Quaternaire
1960s – Humilly-1/2 (St-Julien-de-Genevois), Faucigny-1 – Petroleum Exploration
Thônex – 1993 – geothermal investigation
Peissy-1 – Hydrocarbon wells
7BHs – BP-France (Canton Geneva)
Mount Sion Motorway Tunnel – A41
Lake Geneva Tunnel
UNIL: Applied Geology Research
CERN: LHC, VLHC (GADZ)

19. BRGM – French Geological Reference Platform
French Geological Reference Platform ( platform)
“Acquisition and management of geological data that involves the entire French geosciences community (university laboratories, companies, etc.)
1/ subsoils databank (BSS)
Geological and geophysical surveys planned
Multi-annual programme that will be deployed in stages across France through regional work programmes”

20. BRGM – French Geological Reference Platform

21. Next Steps PHYSICS Requirements & Granularity
Priorities & Critical Areas
Responsibilities & Collaborations
Opportunities
GEOLOGY
ENGINEERING
GIS