Future Circular ColliderARUP: Status of Geological Models

Yung Loo

Andy Kervell

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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)

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Work Stages

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Preliminary Geological Studies | Decision Aid Tool

  100km(230mASL)

100km (310mASL)

Gradient, % 0.5 0.1Mean Shaft Depth, m 240 224Max Shaft Depth, m 609 619Mean total length of all shafts, km 2.21 2.05Molasse:Limestone:Moraine(Dependent on NW Jura/Molasse contact)

80:20:0to

(72:28:0)

75:20:5to

(67:28:5)

A. Key Variables:• Tunnel Elevation• Tunnel Gradient & Inflection Point• Shaft Position on Ring

B. Key Outputs:• Summary statistics:• Shaft depth +uncertainty

C. Accessible Interface

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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)]

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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.

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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

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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.

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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.

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Geological Studies – Next Stages

St-Julien-enGenevois

Annemasse

Seyssel AnnecyBonneville

St-Claude Douvaine

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Geological Studies – Next Stages

BRGM: Carte Geologique de la France a 1/50 000, no. 654

BRGM: Carte Geologique de la France a 1/50 000, no. 678

e.g.Annemasse: Mapped Molasse-Quaternary ContactAnnecy-Bonneville: Mapped cross-section on Saleve

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Next StagesConstraints• 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

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Decision Aid Tool (GIS) – Next StagesGeometric Attributes

CERN: 80km Ring Concept Shieldhall Tunnel

Geotechnical Attributes

ArcGIS Platform Gaming Engine Based Geological Models

Combined Attributes+ Outputs

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Decision Aid Tool (GIS) – Next Stageshttp://glogis04/cern/index.phpPreliminary Proof of Concept

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Decision Aid Tool (GIS) – Next Stages

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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)

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BRGM – French Geological Reference Platform

• French Geological Reference Platform (http://www.brgm.eu/content/french-geological-reference-platform)

• “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”

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BRGM – French Geological Reference Platform

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Next StepsPHYSICS

GIS

GEO

LOG

Y

ENG

INEER

ING

• Requirements & Granularity• Priorities & Critical Areas• Responsibilities & Collaborations• Opportunities