[Bell Historians] Steelwork into masonry (spelling corrected!)

[David Beacham]

It would be interesting to hear the comments of those who are better qualified than I am on this question (i.e the purpose of "anti-drag" cleats). In *theory* (which I emphasise), a properly designed and constructed frame foundation grillage should transfer all the horizontal forces into the walls that are parallel with those forces, such that there is then no end-thrust into any of the walls. In this perfect situation cleats would, indeed, be unnecessary. To achieve this requires the beams to be of adequate stiffness and, most importantly, diagonally braced so as to resist parallelogram distortion.(Plus other refinements such as all bolts to be a close fit in reamed bolt holes.) As regards the stiffness factor, for the past 30 years or so the steel used has been of Universal Beam section, which has parallel flanges. Formerly, the steels were Rolled Steel Joists that had tapered flanges. Is it not the case that UBs are inherently more flexible than RSJs?

In practice, I assume that the theoretically perfect grillage is not achievable and some end loading of the steels is inevitable. The late Donald Ascough (structural engneer) presumably did not accept this because, harking back to the Stourbridge controversy of a few years ago, he propounded his belief that beams ends should be free to move (longitudinally) to allow for thermal movement. It would appear that there are other engineers and architects who still think this way.

What, I think, has been learnt from long experience is that grouting-in beam ends with mass concrete, not a mix of rubble, etc, if properly done works and is safe. Returning, however, to my initial comments, it is vital that the steel sections and diagonal bracing are adequately specified so as to keep end loading to an absolute minimum. (Is there a question mark over this in the case of Kings Lynn, I wonder?)

DB






  ----- Original Message ----- 
  From: Richard Offen 
  To: bellhistorians at yahoogroups.com 
  Sent: Saturday, February 24, 2007 8:03 AM
  Subject: Re: [Bell Historians] Steelwork into masonary



  > We call them called drag cleats - in other words, they help provide 
  drag. I 
  > suppose you could look at this both ways. Sorry! M
  > 
  > Matthew Higby & Co Ltd,

  I remember either Eric Fowler or Arthur Fidler (can't remember which 
  however!) telling me of one job they did for Taylors where the church 
  architect insisted on the drag-cleats being cut off the foundation 
  girders before he would allow them to be inserted in the tower walls. 
  No amount of explantion as to their purpose would persuade him 
  otherwise.

  As Chris Pickford has already said, the architect is the boss on these 
  occasions and the contactor has to do his bidding.

  Richard



              
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.ringingworld.co.uk/pipermail/bell-historians/attachments/20070224/258e5f5a/attachment.html>