Presentation on theme: "Meeting No. 2 : Vibration studies for HL-LHC Civil Engineering Dr David Hiller Claire Wilson Matt Sykes 18/02/2015."— Presentation transcript:
Meeting No. 2 : Vibration studies for HL-LHC Civil Engineering Dr David Hiller Claire Wilson Matt Sykes 18/02/2015
2 Mechanical Excavation -30-80Hz Region dominates -Tails off to 200Hz Re-cap: Post-Meeting no.1 45m away, PPV ~ 2x10 -4 m/s, 50Hz -= zero-to-peak displacement of 6x10^-7m (0.6μm) [comparable to 1μm limit?] 2-3% of the max at 200Hz
Sandvik MT360 (60 Tonne) Proposed Roadheader for Hi-Lumi
Case Study - Roadheader Vibrations ProjectLocationGeology Lowest predicted ground borne noise vibration criteria PPV (where possible at a distance ~40m) Range of ground borne noise vibration recorded PPV Comments Any project guidance on sensitive structures/equipment Brisbane Airport Link, 2006 1 Brisbane, Australia Rock (limited info) 0.01mm/s at 40m distance n/a Focus on damage/human comfort in buildings Typical satisfactory vibration levels for sensitive buildings – Maximum 0.5mm/s Brisbane Airport Link, changed project, 2008 2 Brisbane, Australia Rock (limited info) 0.01mm/sn/a Focus on damage/human comfort in buildings n/a BaT project 3 Brisbane, Australia Rock (limited info) 0.08mm/s at ~35m distance n/a Focus on damage/human comfort in buildings Sensitive structures identified Linking Melbourne East- West Link 4 Melbourne, Australia Basalt and siltstone 0.15mm/s at 40m distance n/a Focus on damage/human comfort in buildings Typical satisfactory vibration levels for sensitive buildings – Maximum 0.5mm/s Sensitive structural project 5 Australia Weak rock (sandstone) 0.2 mm/s 0.05-0.8mm/s (no distance information) Safely within vibration criteria for “sensitive structure” Road header successfully used in close proximity to sensitive structural elements Northern Link 6 Brisbane, Australia Rock (limited info) Threshold was assessed as that of human perception ~0.15mm/s 0.02-0.26mm/s (no distance information) Focus on damage/human comfort in buildings Typical satisfactory vibration levels for sensitive buildings – Maximum 0.5mm/s Table summarising the vibration levels for different projects, specifically using a road header
Conclusions Sandvik data as a comparison – lowest values they have presented are in the 0.01mm/s range at 40m distance, or just below – therefore they are capable of reaching the same order of magnitude of vibration as suggested and achieved in the presented past projects. But is this within tolerable physics machine limits? Possibilities for mitigation are small to none “Mitigation options for mechanized tunnelling activities are limited. In some circumstances, it might be possible to limit working hours” - British Standard Possibility to engage with Sandvik with further detailed geotech parameters and vibration criteria to understand in more detail possibilities and limitations Identified conventional vibration limits of existing roadheader machines. Need to understand if these are tolerable, and physics requirements can be compatible at these limits.
HL-LHC Vibration Studies : Meeting No. 2 References: 1. Brisbane Airport Link, Environmental Impact Statement, Construction Noise and Vibration, 2006 2. Brisbane Airport Link Changed Project, Noise and Vibration report, 2008 3. BaT project, Appendix D, Noise and vibration report, 2014 4. Linking Melbourne East West Link, Tunnel Vibration and Noise Assessment, 2013 5. Sensitive project, Noise and Vibration Monitoring Report 6. Brisbane Northern Link, Detailed Feasibility Study, Noise and Vibration, 2008 7. BSI British Standards, BS5228-2:2009, Code of practice for noise and vibration control on construction and open sites, Part 2: Vibration 8. Hiller (2011) The prediction and mitigation of vibration impacts of tunnelling, Paper Number 5, Proceedings of ACOUSTICS 2011