@Greenalleycat - Thanks for your example. Fortunately I have a pretty solid tread configuration with a flat plate that extends almost to the edge of the tread and a vertical fin on the front that stiffens it up. I have done treads in a similar way to your example before and had the same...
Good points and thanks again for your thoughts on this, they've been very helpful.
At the 2 points where I'm connecting into wood floors I will definitely have them add blocking and coil strap to drag some horizontal load into the diaphragm.
Unfortunately the handrails will be attached to a wood wall primarily.
I agree that the welded angles won't help much for torsional strength but they do almost double my Ix (transformed section) which makes a notable difference in the AISC vibration calcs, about 20% increase in Hz.
Thanks for...
@KootK thanks for your insights.
I'm using Risa 3d which does have a setting that you can turn on to account for torsional warping so I think I'm set there. I also have some extra stiffness left unaccounted for from the L4x4 angles that are welded to the top which makes me feel better.
As far...
@Phuduhudu Thanks for your response! I do have seperate load cases set up where each tread is only loaded on one side. The 300# pt load is producing the worst deflection because I modeled it right at the end of the tread. Thanks for the article too, I like the idea of using a smartphone to...
Typically when I've done this in the past I've sistered the additional members for almost the full length (usually stop around 1' from the ends since you don't need it for shear) of the joist but this has usually been with a bigger hole or notch. if you do a shorter segment your really moment...
Just looking for a reality check/opinions on this. I'm designing a mono stair stringer for a client (pdf attached showing the layout and section). The stair has 2 short runs with landings and one longer run. The client would like to keep the monostringer as thin as possible. I'm suggesting an...
Thanks for the responses!
Icebloom - The composite steel analogy is a good one that I hadn't thought of. I also didn't know about the HILTI filling washers but those look cool for future use.
cliff234 - Since there is soil up to the top of concrete I'm not too worried about wind loads in the...
A couple other thoughts: in this condition soil pressure is acting out of the page so the plate is on the tension face of the concrete, I would also have them fill the bolt holes in the steel plate with epoxy so that there's no space for the plate to slip before the bolts are engaged.
Can you bolt steel to existing concrete and use it as tension reinforcement? Or do you have to use something like FRP that is continuously adhered to the concrete? I don't do a ton of advanced concrete design but I'm wondering if there is code justification for something like the attached repair...
