yung loo 25.06.2014 fcc: gis & tunnelling update
TRANSCRIPT
Yung Loo
25.06.2014
FCC: GIS & Tunnelling Update
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FCC: GIS & Tunnelling Update
1. GIS Progress
2. Alignment: Horizontal / Laser Straight
3. Data Interpolation
4. Preliminary Findings• LHC Crossing under ATLAS Point 1• Bored vs IMT
• Total Shaft Depths• Risk Matrix
5. Next Steps
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GIS Tool Development – Current Status
Web-based GIS Decision Aid Tool
Dynamic Chart:• Profile surface elevation
and geology• Profile of tunnel• Shaft Locations • Warnings when tunnel
above ground level
Dynamic Tables:
• Depth to tunnel • Shaft Length through
geology layers• % age of tunnel
intersecting geology• ±3km horizontal
variance in results for shaft depth
User Inputs• Alignments of 6 FCC Options• Interactive alignment location on map• Alter Shaft locations (10%) - slidebar• Select Tunnel Depth - slidebar• Select Tunnel Gradient – slidebar• Select point of inflection of tunnel gradient
Outputs
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GIS Tool Development – Current Status
Web-based GIS Decision Aid Tool
Dynamic Chart:• Profile surface elevation
and geology• Profile of tunnel• Shaft Locations • Warnings when tunnel
above ground level
Dynamic Tables:
• Depth to tunnel • Shaft Length through
geology layers• % age of tunnel
intersecting geology• ±3km horizontal
variance in results for shaft depth
User Inputs• Alignments of 6 FCC Options• Interactive alignment location on map• Alter Shaft locations (10%) - slidebar• Select Tunnel Depth - slidebar• Select Tunnel Gradient – slidebar• Select point of inflection of tunnel gradient
Outputs
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GIS Tool Development – Current Status
1 2 3 4 5 6 7 8 9 10
To Develop:
• Cretaceous boundary:• Basement• Massifs Calcaire
• Lake Superficials/Moraine
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Geographic Reference System
• Alignment Geographic Reference System:- Laser straight / Earth curvature- Geoid- Ellipsoid- Inherent distortion
ILC for CERN Site (Horizontal)
This was ok for ILC
Geographic Reference System
• FCC Tunnel alignment is following Earth curvature and appears horizontal as flattened
when projected with LV95
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Geographic Reference System
WGS 84 Swiss Lv95
• A geographic coordinate system (WGS84), uses a 3d spherical surface to define locations on the earth.
• A projected coordinate system (Swiss Lv95) is defined on a flat, 2d surface.
• All data uses Swiss Lv95, which effectively ‘flattens’ the data and removes the curvature of the earth.
• Therefore this flattening removes any curvature in the alignment when viewed in profile.
Datasets• Terrain:
Shuttle Radar Topography Mission (SRTM)
• Geology:Le système d'information du territoire à Genève (SITG)
• Coordinate System:SwissLV95
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Geographic Reference System
• Swiss LV95: Geographic coordinate system- Uses Bessel 1841 ellipsoid- x,y,z derived directly from a fundamental point at Zimmerwald
Federal Office of Topography, swisstopo
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Geographic Reference System• Scale Distortion: 75-100ppm ~ 2.4-3.1m over 31.8km (~relative 0.7m)
• Meridian Convergence: angular difference from north (-0.9 to -1.0, ~relative 0.1º)
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Point Interpolation
• PostGIS function which interpolates a point on a line. Location of point is a fraction of total length of the line.
• 1% intervals used. • For 100km alignment, a point every 100m.
83km, a point every 83m.
• All geology information has been converted to raster format using the ‘Topo to Raster’ tool in ArcGIS
• Uses an iterative interpolation technique, based on IDW and kriging.
• Optimised to have computational efficiency of local interpolation methods without losing surface continuity of global interpolation methods.
• Allows for the created DEM to follow abrupt changes in elevation.
P3P1 P7
(450m)(359m) (350m)
FCC (horizontal)
FCC (at grade)
?m
Superficials
MoraineMolasse
Tunnellingunder lake
(330m)(310m)
(230m)
Vertical depth below Point 1
30m
50m130m
Effect of tunnel position on Point 1 connection
Alignment & Tunnelling Type – Preliminary Results
To be updated with Cretaceous geology
Horizontal Alignment: Above GL
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Lake Crossing: Tunnelling Considerations
IMT Bored Bored Remarks
Ground conditions Superficials Moraine MolasseGeotechnical Risks, with which can
be designed for.
Excavation Technology + + ++
All proven technology at the anticipated depths, lengths &
diameter. More extensive ground treatment in non-molasse options
Logistics: Segmental vs prefab and casting basin
- + +Navigation issues, inland segment
yards, near shore casting yards, floating docks
Long term durability: Stability, joints, maintenance & operation
+ - - Increased joint connections in TBM
Environmental: Spoil disposal, dredging, ship impacts
- + +IMT dredging can be used directly as
construction material
Energy: Power and fuel consumption
+ - -IMT less energy requirements, more
fuel requirements
Cost and programme ? ? ?To determ
ine furth
er in st
age 3
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Next Steps- GADZ Cretaceous data inclusion- GIS programming completion and integration- Screening results- Stage 2: Requirements, constraints & alignment optioneering