Future Circular Collider
ARUP: Status of Geological Models
Yung Loo
Andy Kervell
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)
2
Work Stages
3
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
4
Gradient, %
Mean Shaft Depth, m
Max Shaft Depth, m
Mean total length of all shafts, km
Molasse:Limestone:Moraine
(Dependent on NW Jura/Molasse
contact)
100km
(230mASL)
0.5
240
609
2.21
80:20:0
to
(72:28:0)
100km
(310mASL)
0.1
224
619
2.05
75:20:5
to
(67:28:5)
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 [seismic survey carried out by Fiore (2011)]
• Below ~250mASL.
• Tunnel through moraine? Lake sediment rockhead?
• EPBM? / Slurry TBM? / Immersed Tube (IMT)?
5
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.
6
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
7
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.
8
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.
9
Geological Studies – Next Stages
St-Claude
10
Douvaine
St-Julien-en
Genevois
Annemasse
Seyssel
Annecy
Bonneville
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
11
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
12
Decision Aid Tool (GIS) – Next Stages
Geometric Attributes
Geotechnical Attributes
CERN: 80km Ring Concept
ArcGIS Platform Gaming Engine
Based Geological Models
13
Shieldhall Tunnel
Combined Attributes
+ Outputs
Decision Aid Tool (GIS) – Next Stages
Preliminary Proof of Concept
14
http://glogis04/cern/index.php
Decision Aid Tool (GIS) – Next Stages
15
16
17
Available Data
• http://infoterre.brgm.fr/viewerlite/MainTileForward.do
• http://geoservices.brgm.fr/wms-c.html
• 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)
18
BRGM – French Geological Reference Platform
• French Geological Reference Platform
(http://www.brgm.eu/content/french-geological-referenceplatform)
• “Acquisition and management of geological data that involves the
entire French geosciences community (university laboratories,
companies, etc.)
• 1/50 000 + subsoils databank (BSS)
- Geological and geophysical surveys planned
• Multi-annual programme that will be deployed in stages across
France through regional work programmes”
19
BRGM – French Geological Reference Platform
20
Next Steps
•
•
•
•
PHYSICS
GEOLOGY
ENGINEERING
GIS
21
Requirements & Granularity
Priorities & Critical Areas
Responsibilities & Collaborations
Opportunities