I am designing a pedestal over a spread footing to support a cantilevered hss column. The column has fairly large moments and very light axial loads. I believe the pedestal falls into the ACI 318-19; 2.3 definition of a beam, "Member subjected primarily to flexure and shear, with or without...
I've attached a pdf of a substation structure that I designed and is currently being fabricated. The only specifics that I submitted to the fabricator were requiring that the W8x28 beams be ASTM A572 GR 50 or ASTM A992 GR 50. I believe that the fabricator added their own specs prior to sending...
I'm confused by the purpose of Eqn F11-1.
Mn = Mp = Fy Z <= 1.6 Fy Sx
if Z = (1/4)(width)(thickness2) and Sx = (1/6)(width)(thickness2)
and 1.6*(1/6) = 0.267 on the right side of the equation and 1/4 = 0.25 on the left side of the equation then won't the left side of the equation always...
I am designing some braced frames which use rod x bracing. Where the tension rod meets the gusset plate, I plan on using a 3 1/2 clevis with a 1.75" Dia A36 pin. I can size the gusset plate geometry based on the uniform force method but I'm running into issues with the Pin connected member...
Hello all,
I am designing a 45' tall x 20' wide braced frame shown in the attached pdf. It consists of two knee braced frames above a tension only x brace. I'm hoping that someone can either confirm my assumptions for k factors or point me in the right direction for correcting them. My columns...
I have a steel beam loaded in both the strong and weak axis. I was hoping someone could point me in the direction of a part in AISC Steel Construction Manual that addresses this. I've found items discussing combined bending with axial forces but can't seem to find a part that addresses combined...
Does anyone know of a code reference that gives some sort of exemption for designing sill bolts according to appendix d? I feel like at some point I've seen this but cannot remember where now.
If not, does anyone have examples of a method to prove the tight edge distances on sill bolts work...
I am designing a middle school gymnasium storm shelter using 6" total thickness non-composite concrete slab over 1.5" form deck. I've read through the diaphragm sections of ACI 318 and saw the 3:1 aspect ratio requirement for considering the diaphragm rigid. For simplicity sake, I would like to...
The attached sketch shows a large 50' x 75' wood diaphragm with a small bumpout 10' x 50' diaphragm next to it. What are the rules for treating a small side portion like the 10' x 50' bumpout as if it will not act as a beam but rather just transfer its shear directly back to the main diaphragm...
Anyone out there have a slick detail that they've used for an inside corner where you have chord/strut forces in each direction? I feel like this is a common enough scenario that there is probably a common way of dealing with each force but I haven't found a great option in the connector...
I am putting together a set of calculations to justify the details/design that the a steel fabricator put together for a very typical office building stair set. They plan to connect stringers to walls with 1/2" diameter wedge bolts at 2'-0" o.c.
I've shown the detail in the attached pdf. My...
I am designing a storm shelter which uses interior masonry walls as shear walls as shown in the attached detail. My in plane shear wind load from concrete deck to masonry wall is roughly 1000 lb/ft and my uplift tensile wind load is roughly 1280 lb/ft. I believe the AISC shear connector...
I am designing a storm shelter using fully grouted 8" cmu block reinforced at each face in each cell with #5 vertical bars. The first page of the attached pdf shows my proposed reinforcement layout at bond beam locations over doors where I need the bond beam to be able to span vertically for...
Hi all,
The attached pdf shows a cantilevered beam with both positive moment and negative moment on the backspan and all negative moment on the cantilever. The beam is prevented from translation/rotation at each support and has midspan bracing in the backspan. The slab above will provide...
Hello All,
I'm designing an indoor mezzanine w/ pretty light seismic loads in SDC B. I'm curious how people analyze diaphragms where the shearwalls are angled w/ respect to the chords. I know that ASCE references it as an irregularity but I've never seen an explanation of the actual physics...
If you use a thru bolt in a 3 wythe brick wall, how would you determine the shear capacity of the bolt? I assume you would use the bearing strength of brick, the diameter of the bolt and some other safety factors. Has anyone seen this discussed in the codes?
Thanks
I am designing a frame with tension only diagonal bracing that stops midway up the structure. I am landing on an 8" slab at the base and would like to stick with pinned connections at the base. I'm kind of having trouble wrapping my head around how the upper diagonal braces create rigidity such...
2012 AWC 15.3.3 gives the requirements for nailing together the separate plys of a built up wood post. I'm curious if other designers think it's necessary to state these requirements or provide a detail similar to Figure 15C in the design drawings. My firm's position is typically that by...
When designing a balloon framed stud wall with a parapet what span lengths do you use for the effective wind area = (span length)*(span length/3)? For example, if you have a 15' tall wall with a 5' parapet and you are designing the stud, would you use one single effective wind area of...
We are having a little debate about how tension forces would resolve themselves when they are occurring simulataneously on the same member. In my attached sketch, I show two Pre Engineered Metal Building Columns with outward 10k forces applied to them.The building is used for soccer fields so...
