1. FCC Tunnel Civil Engineering and Geology John Osborne (CERN GS-SE) 4 April 2014

2. John Osborne (CERN) 2

3. Goals of the meeting : –Review status of studies –Ensure no duplication of tasks –Understand what geological data exists –Establish where to find additional data –BRGM contact –Understand the role of GIS –Agree reporting milestones and future review dates John Osborne (CERN) 3

4. Potential locations Options for a ring tunnel have been proposed in the past : Summer 2012 CERN GS-SE group studied the pre- feasibility of an 80km ring tunnel in the CERN area. Pre-feasibility study of an 80km tunnel project at CERN prepare for the European Strategy for Particle Physics 2012 : http://indico.cern.ch/event/175067/call-for-abstracts/165/file/1.pdf http://indico.cern.ch/event/175067/call-for-abstracts/165/file/1.pdf 4 1980’s :LEP 30km and 27km tunnel locations 2001 : VLHC 240km tunnel location 1997 : VLHC 113km tunnel location John Osborne (CERN GS-SE)

5. Potential locations : European Strategy for Particle Physics Several locations have been studied for the possibility to construct an 80-100km ring tunnel in the CERN area. –Location constraints CERN area Connected to LHC/SPS at one point Limit depth of access shafts 5 John Osborne (CERN GS-SE)

6. Possible machine layouts 6 P.Lebrun

7. Single tunnel, longitudinal ventilation 7

8. Single tunnel + refuge, longitudinal ventilation FCC I&O meeting, 140326 8

9. Single tunnel, transverse ventilation FCC I&O meeting, 140326 9

10. Single tunnel with shielded technical & safety zones FCC I&O meeting, 140326 10

11. Double tunnel 11

12. Feasibility /Risk Issues of the Options Some examples of issues (needs to be studied in more detail) Environment –Risk of environmental impacts such as civil engineering, social acceptance, pollution of aquifers etc –Risk of encountering hydrocarbons –Risk of EIA rejection Costs –Risk of cost increase due to all issues mentioned 12 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 Total Option 1 5300545542 33 Option 2 2033332232 23 Option 3 ……. 1022221125 18 High Low Feasibility John Osborne (CERN GS-SE)

13. Develop a geological tool to allow comparison of the various tunnel options Circumferences, shapes, inclination (max 2%, out of plane ?) etc. to be easily compared non-planar tunnel ? Optimise shaft positions to minimise depth (+/- 2km ?) Bypass tunnels instead of shafts ? John Osborne (CERN) 13 Next Steps

14. John Osborne (CERN) 14