SMB - Ge · 2019. 12. 10. · • Moraine/molasse interface not certain, cavern close to interface....
Transcript of SMB - Ge · 2019. 12. 10. · • Moraine/molasse interface not certain, cavern close to interface....
SMB
Tunnel optimisation for future colliders at CERN
Alexandra Tudora John Osborne
SITG Forum
27.11.2019
SMB Agenda
• Introduction
• CERN infrastructure and proposals for future colliders
• Tunnel Optimisation Tool
– Requirements
– Data interpretation and input
– How TOT works
• Civil Engineering overview for FCC and pre-construction planning
• Current status of FCC study and going forward
SMB
Future Accelerator Studies Section (FAS)
Section Leader: John OSBORNE
Engineers
International Linear Collider CLIC, Muon Collider
Jonathan Gall
Tunnel Asset Management
Alexandra Tudora
Future Circular Collider (FCC)
Physics Beyond Colliders (PBC)
SMB-SE-FAS Section Organisation
Ben Swatton
Tunnel Fibre Optic Studies
Zhipeng Xiao
Selected CE Project Delivery
Eliseo Perez-Duenas
SMB CERN – The World’s Largest Particle Physics Laboratory
CERN – European Centre for Nuclear Research
SMB Existing tunnels at CERN
Large Hadron Collider :
- 27km circumference
- 50-175m depth
Total underground tunnels >70km More than 80 Caverns
LEP tunnel built in mid 1980’s
SMB Underground works in progress at HL-LHC
SMB Proposed Future Colliders at CERN
‘’The European Strategy for Particle Physics provides a clear prioritisation of European ambitions in advancing the particle physics science. The Strategy is due to be updated by May 2020 to guide the direction of the field to the mid-2020s and beyond.’’ https://europeanstrategyupdate.web.cern.ch/welcome
SMB The Future Circular Collider
Collision energy: 100TeV
Circumference: 80km-100km
Physics considerations: Enable connection to the LHC (or SPS)
Construction: c.2025-35
Cost: ˜6Billion CHF for Civil works
Aims of the civil engineering feasibility study: Is 80km-100km feasible in the Geneva basin? Can we go bigger? What is the ‘optimal’ size? What is the optimal position?
Spoil: ˜10million m3 of excavated material
SMB
Option 2: 80km Lakeside Option 1: 80km Jura
Potential locations - European Strategy 2012
High
Low Feasibility
Risk
water ingress
heaving ground
weak marls
hydro carbons
support & lining
ground response &
convergence
hydrostatic pressure & drainage
Pollution of
aquifers
effect of shafts on
nature
effects of shafts on
urban areas
Tota
l
Jura 80 5 3 0 0 5 4 5 5 4 2 33
Lake 80 2 0 3 3 3 3 2 2 3 2 23
Lake 47 1 0 2 2 2 2 1 1 2 5 18
Pre-feasibility study focused on: • geology & hydrogeology, • tunneling & construction, • environmental impacts
Result: for the 80km long tunnel location 2 ‘80km Lakeside’ is most feasible.
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The Study Boundary was defined by: • Topography (avoid Jura, Vuache, Pre-Alps) • Geology (maximise tunnelling in molasse) • Geneva Lake (lake depth increases in NE direction) • Connection to LHC
FCC Study Boundary
Multiple shapes and sizes studied within the boundary
SMB
Bespoke tool
• Common Data Environment
o Single Source of Data and ‘Truth’
• Open Source Development
o Accessible user-friendly interface
• Integrated visual decision aid
platform
Tunnel Optimisation Tool
SMB Requirements and development of TOT
Physics requirements: o Machine shape
(lengths of straights sections and arcs);
o Location of experimental points and injection from the LHC;
Geology: o Surface and subsurface mapping o Integration within 3D Geological Model
Civil Engineering: o Intersected geology o Depths of shafts o Overburden pressure o Surface sites (environmental constraints, access etc)
Opt
ione
erin
g It
erat
ion
Cos
ting
and
Ris
ks A
naly
sis
SMB 3D geological model
The DEM has been sourced from the EU Copernicus programme and has a quoted vertical accuracy of +/- 2.9m
Digital Elevation Model (DEM)
SMB Data interpretation and input into TOT
Molasse rockhead contours
This data was then processed by Geneva Geo Energy to create a Limestone rockhead depth map covering the FCC study area. GGE cautioned that due to interpolotion over large distances, local inaccuracies of up to +-50m are possible
(Geneva Geo Energy, 2014)
Limestone rockhead contours
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Prealps
Voirons - Faucigny
Jura
Vuache Mandallaz
Regions with high uncertainty and challenging geology
Geological interpretation
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• Geology underneath Lake Geneva is not yet well understood
• Data available from boreholes and seismic scans
• Molasse bedrock covered by a deep layer of moraines
140m shaft depth
Lake Geneva Bathymetry
Data interpretation and input into TOT
71m 58m 60m
87m
SMB
• Natural parks • Areas of biological significance
and wetlands • Protected water sources • Groundwater (aquifers)
Environmentally sensitive areas
Data input into TOT
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Buildings
• Buildings data covers both the Swiss and French sides of the FCC study area.
• In Switzerland, the data includes buildings with planning permission
Data input into TOT
SMB SITG data
SMB
Geothermal boreholes
• Over 1800 boreholes in the FCC study area ranging from 20m – 400m in depth.
• Only 10 to 20 boreholes are usually within a 50m radius of a given FCC tunnel option under study
Input data into TOT
SMB FCC TOT demo
SMB FCC Conceptual baseline footprint
Present baseline position was established considering: • lowest risk for construction
Avoid Jura limestone and the Pre-Alps Only one sector containing limestone. ~90 % molasse – suitable
ground for tunneling Significantly reduced total shaft length. Deepest shaft at PF
proposed to be replaced with an inclined tunnel Avoids extremely large overburden.
• feasible positions for large span caverns (most challenging structures) • experimental Site at Point A on existing CERN land.
97.75km tunnel circumference
SMB
24 Underground civil infrastructure for FCC - 3D schematic (not to scale)
Shafts: Experimental Shafts: 15 m dia. + 10 m dia. Service shafts: 12 m dia. Magnet delivery shaft:18 m
Service Caverns • 25 m x 15 m x 100 m
Small Experimental Caverns 30 m x 35 m x 66
Large Experimental Caverns 35 m x 35 m x 66 m
Beam Dump Caverns • 10 m x 10 m x 50 m
Alcoves • 25 m x 6 m x 6 m • Located at 1.5km spacing
Tunnels: • 97.75 km of 5.5 dia. machine tunnel • Approx. 8 km 5.5 dia by-pass tunnels
FCC Civil engineering overview
SMB FCC pre-construction planning
European Strategy Update 2020
Types of site investigation: • Collection of existing information • Walkover survey • Geophysical investigations (to define interfaces) • Boreholes
• Site testing (eg Insitu stress test, point load testing, SPT) • Rock laboratory testing.
Phases: Feasibility: Non-intrusive investigations to allow consolidation of alignment. Focus on access points, Lake crossing and the Rhone and Arve crossings. Principal: Substantial portion of the geotechnical investigations. As a result of this, the alignment might need to be changed. Additional: Any investigations required for the final design, emphasis on obtaining date required for the contractors.
Conceptual Design Report
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• Information near to CERN is strong due to previous experience on LEP/LHC.
• Multiple deep boreholes in the area.
Vallée de l‘Arve Mandallaz
Le Rhône Lake Geneva
• No deep borehole information available in the area.
• Complex faulted region. • Molasse/limestone interface uncertain.
• Moraine/molasse interface not certain, cavern close to interface.
• Lack of deep boreholes in area.
• Seismic and borehole information for lake crossing from proposed road tunnel, but layered nature of lake bed leads to uncertainty.
• Location of the interface between molasse and molasse subalpine not certain, tunnel alignment in proximity.
• Limestone formation known, but characteristics and locations of karsts unknown.
• Alignment close to limestone rockhead.
• The exact location and angle of the limestone/molasse interface undefined.
Geological uncertainty
SMB Going forward
Currently focusing on
• continuous desktop study of geology
• planning for preparatory works to start the site investigations campaign
• optimising the footprint
CERN Tunnelling Workshop (23-24 October 2019) - Review software and decision aid tools available and what the industry are using for alignment optimisation → https://indico.cern.ch/event/823271/
Exploring GIS tools and alignment optimisation software that could facilitate future colliders studies from
feasibility stage throughout detailed design stage up to construction start
Awaiting news from European
Strategy for Particle Physics Update May 2020