Padstone Design At Masonry Wall End

[Aiden Wilkins]

Hi all,

I have a question regarding structural design (I am doing it to BS 5628) of concrete padstones - primarily in this case where they are close to or right at the end of the wall.

In this example case, I have a beam 100mm wide bearing on the end of a wall:

I require the load to be spread more than it will be without a padstone and so I am putting one in. Until now I have been using Tedds but am now questioning it. The formula they use basically just multiplies the stress at the base of the beam by 2/3 - I am not sure why this is but it does not seem right/a good way of doing this.

I have made a preliminary calc that basically just uses triangular stress distribution to obtain the stress at the bottom of the padstone after taking a 45 degree line but I would like to know how others do it so that I can have a better idea of the best way to go about this.

Cheers,

Aiden.

 

[JLNJ]

The bearing pressure might spread out at 45 degrees normal to the beam span, but the direction in your sketch I would use maybe 1.5*Lb as see how that works out.

The applied load needs to be equal and opposite of the reaction in the wall.

 

[GeorgeTheCivilEngineer]

Quick solution - 100x100x10mm bearing plate and centre the beam on the centre of the padstone. This will put load down the centre of the padstone. I often have to do this when loads get too high to just be sat as shown.

If you are worried about tie forces, make it a 200x100x10 and put an anchor into the padstone.

 

[jayrod12]

I call those bearing bars when I put a piece of steel to promote rectangular stress distribution. It's often narrower than 100mm, but also sits on top of a larger steel bearing plate. It essentially instantly doubles the bearing capacity of the plate where the steel beam sits on a masonry wall.