Heavy loads might also tend to cause plate buckling, in which case (can you guess?) put stiffeners in there. You might have to size the saddles for longitudinal bending from the friction loads, uplift or overturning moments from wind, thermal loads, so there could be anchor bolt tension loads (flange bending) to contend with. Size the top one so that the teflon always remains covered before and after movement. Sometimes there is a pressure limitation on a teflon friction reducing pad that goes inbetween the bearing plate and the saddle plate. flange bending only) If very heavy loads, they may need to have an area giving a pressure load less than the bearing capacity of the concrete they are usually attached to. Large saddles (on equipment or large headers) are designed just like structural base plates for columns, etc. They're cut to the right height and that's about it. I've never seen anybody design a pipe shoe.
