Are you concerned about shear, uplift, or both?
I have found if you try to design a washer for uplift by checking bearing perpendicular to grain, NDS will give you a very conservative value. I think this is because the bearing perpendicular to grain value in NDS limits deformation, not...
Arun238, I do not disagree with you. I meant in a seismic zone, I believe it is prudent to assume any concrete member is cracked.
I should probably be a little more careful about what I assume in the future. I agree that if something is likely to be cracked (like the tension side of a...
I am not in a seismic area (Wisconsin), so I normally assume uncracked concrete. It is difficult sometimes to make things work using the cracked concrete values.
DaveAtkins
Was there a regulatory body or official who approved the plans? If so, I think you are fine - Florida is transitioning from one code to another.
DaveAtkins
It sounds like you are talking about the overburden above the footing, outside of the arch culvert. I would consider that load, as it will not be balanced by soil on the inside of the culvert.
DaveAtkins
bones206 has it right. The top chord only model does not account for vertical deflection at each node, as you get with the full joist model. If you knew the vertical deflection at each node, and modeled that as springs in the top chord model, the results would be a lot closer. Although, axial...
I would be more concerned with the effect the new opening has on the roof diaphragm.
Can I assume the new opening will be covered by a skylight? If so, there won't be any effect on internal and external pressures on the roof.
DaveAtkins
I agree with using a bearing plate in combination with the stiffener plates.
I am also concerned with fatigue. Isn't it better to cut the stiffener plates a little short of the top flange, and avoid welding them to the top flange? I recall seeing somewhere that stiffener plates welded to a...
I think current codes want you to consider the possibility that only 60% of the dead load could be there, not that you have a FOS = 1.5 against overturning. So you may have a bearing pressure issue.
Can you grab any other dead load to help you?
Since this is an existing footing, you may need...
Agree with Smoulder. The horizontal length of the wedge will depend on phi if I remember correctly. The horizontal length of the wedge will be at least twice the height, and could be three or four times the height.
DaveAtkins
Compression in the top flange of the TJI joist due to flexure = the maximum bending moment at midspan divided by the distance between the centroid of the top flange and the centroid of the bottom flange. This will be a value in pounds. Divide that number by the area of the top flange, and you...
If it was an 8 ft wall, I would say something like "this is one of those cases where empirical evidence indicates the floor diaphragm and joists can resist the lateral load from soil."
But since it is a 12 ft wall, I think it warrants some additional consideration. Perhaps calculate how much...