CONTAINMENT OF HEAVY VEHICLES BY BRIDGE PARAPETS OF POST AND RAIL TYPE

The containment capability of post and rail parapets depends, inter alia, on the post spacing. To provide quantitative data on this behaviour, the increased containment obtained by halving the post spacing has been measured in dynamic tests using 5 tonne coaches impacting the parapet at 30 deg. It was found that an aluminium P1 parapet with 3 M post spacing did not contain a coach which struck it with the same severity as the p1 car impact. When the post spacing of the aluminium parapet was halved to 1.5 M it withstood a 2 x p1 impact from a coach, equivalent to the impact of a 20 tonne vehicle at 58 km/h and 15 deg. Halving the post spacing of a steel p1 parapet from 3.66 M to 1.83 M increased its containment capability from 1.6 x P1 impact to 3.2 x p1 impact, a high level of containment equivalent to the impact of a 20 tonne vehicle at 61 km/h and 15 deg.(a) (TRRL) and 0.74. The rather large scatter and poor correlations were due to the following facts: the observation sample was quite small; the observation method, especially the estimate of the runway conditions, was inaccurate. Due to the inaccuracy of the method of observation and the small size of the data sample it was not possible to pay any attention to the combined effects of two or more weather parameters or to the effects of traffic and maintenance work.

  • Corporate Authors:

    Transport and Road Research Laboratory

    Old Wokingham Road
    Crowthorne RG11 6AU, Berkshire,   England 
  • Authors:
    • JEHU, V J
    • Pearson, L C
  • Publication Date: 1979

Media Info

  • Features: Photos; References; Tables;
  • Pagination: 10 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00319235
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Report/Paper Numbers: TRRL LR884 Monograph
  • Files: ITRD, TRIS, ATRI
  • Created Date: Feb 6 1981 12:00AM