1 / 16

Ballast Migration – Progress 7 March 2013 Presentation by Louis Le Pen

Ballast Migration – Progress 7 March 2013 Presentation by Louis Le Pen Researchers: Louis Le Pen and Geoff Watson. Presentation overview. Summary of 10 th January meeting First site monitored Initial results Summary Ballast migration at Weedon November 2006. Meeting 10 th January.

jerry-massey
Download Presentation

Ballast Migration – Progress 7 March 2013 Presentation by Louis Le Pen

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Ballast Migration – Progress 7 March 2013 Presentation by Louis Le Pen Researchers: Louis Le Pen and Geoff Watson

  2. Presentation overview • Summary of 10th January meeting • First site monitored • Initial results • Summary • Ballast migration at Weedon November 2006

  3. Meeting 10th January • Present: Gareth Evans (Senior Technology Engineer (Rail)) – project champion, Paul Parcell (WCML), Kevin Thurlow (WCML), Louis Le Pen (UoS), Geoff Watson (UoS) • Key points: • Where this is known to occur Paul applies a tamp twice policy “has helped” • Stoneblowing is also used at locations of rapid deterioration (e.g. Hodge Lane) • On straight sections of track voiding can occur without migration • Paul’s view is that the subgrade is the cause • Could use GPR data to evaluate further (8 week surveys) • During the speed upgrade “this was a major problem”

  4. Site one: Hodge lane access near tamworth WCML To London • 4 tracks, inner tracks are fast outer tracks are freight

  5. Site one: Hodge lane access near tamworth WCML • LEC2 108m to 109m, fast trains to London (second track in photo) • Stoneblown Dec 2012 because “deteriorating fast” • For January 2013 monitoring no visual evidence of migration

  6. Site one: geophone arrangement

  7. Site one: Weld

  8. Site one: Geophone Arrangement Migration feature 10 11 Vertical 9 8 7 6 4 3 1 Vertical Horizontal 5 2 High sleeper end Weld

  9. How geophone data is interpreted Knowing the response characteristics of the geophone the velocity can be computed Geophone produces a voltage proportional to velocity of the sensor Integration of data leads to calculated displacement Dominant axle and bogie frequencies can be obtained • Note that we generally ignore the first and last axle movements in the displacement trace (start up transients)

  10. Pendolino, next to feature Estimate of at rest sleeper position Range of movement 10 11 • Unusually high movement on inside of bend (V11) – possibly poor support conditions 9 8 7 6 4 3 1 5 2

  11. Pendolino, At feature • Some erratic movements, particularly for V6 and V5 which are the two geophones after the weld and the nearest to it 10 11 9 8 7 6 4 3 1 5 2

  12. Pendolino, After feature 10 11 9 8 7 6 4 3 1 5 2

  13. Pendolino, sleeper movements below Axle 15 • Some variation in deflections but this is not uncommon and has been seen on other sites we have monitored (0.6 mm to 2 mm)

  14. Summary • The Hodge Lane site shows some unusual features and it is possible that the nearby rail weld contributes to unusually complicated behaviour. • However, at previous sites investigated (Weedon 2006) no rail welds were present within the migration features, so it would seem that migration cannot solely be associated with nearby rail welds. • Further sites are needed for monitoring, ideally these would include sites where migration occurs but welds are not nearby • Further monitoring at Hodge Lane planned • More sites needed

  15. Thank-you and any questions?

  16. Geophone references: • Monitoring the dynamic displacements of railway track. D Bowness, W Powrie, A C Lock, J A Priest and D J Richards. Proceedings of the Institution of Mechanical Engineers Part F, Journal of Rail and Rapid Transit 221 (F1), 13-22, March 2007. ISSN 0954 4097. doi: 10.1243/0954409JRRT51. Awarded the IMechE John F Alcock Memorial Prize and the IMechE Thomas Hawksley Medal, 2008 • Determination of dynamic track modulus from measurement of track velocity during train passage. J A Priest and W Powrie. American Society of Civil Engineers Journal of Geotechnical and Geoenvironmental Engineering 135(11), 1732-1740, November 2009, ISSN 1090-0241. doi: 10.1061/_ASCE_GT.1943-5606.0000130

More Related