On a separate topic, if I have a nonbuilding structure that's similar to building (ground supported), for example, an open concrete frame for equipment support, do I just design it based on chapter 12? I can't find the relevant sections in chapter 15 for designing such structures.
The rooftop structure is sitting on the roof slab (12" concrete flat plate) and is not an extension of the building frame.
ASCE 7-16 applies to this project, so I only need to refer to Equation 13.3-1.
After reviewing Section 15.3 again, the first paragraph states that only nonbuilding...
Hi Everyone,
I’m currently evaluating an existing concrete roof due to modifications made to the roof’s mechanical supporting structure.
I’ve outlined my thought process and questions in the sketch below. Feel free to share any comments or suggestions. Any help would be greatly appreciated.
I
Per Table 7-1, a ¾” diameter A325 bolt has a shear capacity of φ * rₙ = 17.9 k when the threads are included in the shear plane. Page 10-89 indicates that bolt shear must be checked with the assumed eccentricity shown in Table 10-9, where e is determined to be a/2 for a 2-bolt connection. Page...
Supplement 2 to ASCE7-22 says this:
I disagree that wave loads should be combined with hydrostatic and hydrodynamic loads, as wave loads themselves are a combination of hydrostatic and dynamic loads (a different vertical distribution than hydrodynamic loads). It's double counting if we do...
Hi everyone,
Can you please advise on the following questions?
1. Per ACI 318-11, Section 12.15, the use of Class A splices is intended to encourage splicing locations away from areas of high tensile stress. Does this imply that Class B tension splices can be used anywhere, since they are...
I'm designing a solid concrete flood wall. I've looked through FEMA P-55 but still have questions on how to combine different flood load cases.
For one case, I think I need to combine hydrostatic + hydrodynamic + impact.
But how should I combine the loads when there is breaking wave? The...
The truss has to dump the load into the shear wall at some point. What is the elevation of that point? If both the top & bottom chords are connected, I would say the middle of the truss.
Thank you! Your explanation is very well done. I was looking from an equilibrium perspective and couldn't figure out why the guide reversed the load.
I have one follow-up question for special case 3. The example in the guide only uses M-induced force to check the beam web's local buckling &...
Referring to Appendix B of the guide, why is the normal force Ne=T+4M/L? M produces a force couple and the forces are not in the same direction. Need help understanding this.
I have a situation where the roof column has no beam frames into it. The tip of the column is connected to diagonal bracing though. What k factor should I use? I'm thinking of using the horizontal stiffness of the bracing as a beam and calculating G. Does this make sense?
