I am trying to calculate the deflection of larger wood diaphragm of an existing building to check the seismic separation. I used SDPWS Eq 4.2-1 to calculate the diaphragm deflection using my pseudo static shear force. However, using ASCE 41-17, I am coming up with almost 2x the deflection I...
How does one determine the C&C wind load on walls of an open building? ASCE 7-16 Section 30.7 details how to calculate C&C loads on roofs, but not walls. Am I missing something?
I am reviewing some rebar shop drawings for a project and have a question regarding the footing ties. On our drawings, we have a 10'-0" wide grade beam and we are showing continuous multi-ties with 6 vert legs. However, on the rebar shop drawings, they are not using continuous multi-ties. They...
I am reviewing a mix design for lightweight concrete to be used over metal deck and also as a polished slab. We specified a 3000 psi mix with a max w/c = 0.45 and a slump of 4". The proposed mix design has a w/c = 0.42, but the slump is listed as 8" +/- 2". Is this slump common for lightweight...
I am working on a plancheck for a SCBF design I did and have a question about column design forces. I designed my columns based on forces developed from a mechanism analysis per AISC 341-10 Section F2.3(I) and F2.3(II). However, I received this plancheck comment:
"Column Designs: Axial load...
I am working on a 3-story moment frame building. It is 6 bays wide and has a 2 bay and a 3 bay moment frame connected by a simple supported beam.
I know the simple supported beam is a collector. But are the moment frame beams collectors? If so, I would need to design them with overstrength...
What is the best method to determine the uplift wind load on a horizontal sunshade (ASCE 7-10)? The sunshade protrudes about 3.5' from the side of the building.
My thought is to use Components & Cladding for a Gable Roof Overhang (< 7 deg). Do you agree?
Thanks!
I am working on a new 3-story woodframe project where the architect wants to use staggered stud walls for the exterior walls and corridor walls.
The exterior would be a 2x6 and a 2x4 staggered on a 2x8 plate. The corridor will probably be a 2x4 and a 2x4 on a 2x6 plate. Has anyone used...
I have a project in construction where I specified 3/4” of camber for a 44’ long W12x65 beam. The steel fabricator forgot to camber the beam and installed all of the stiffener plates (7 locations along its length). Then they cambered the beam.
They flange buckled locally at one location. A...
I am working on the foundation design of a 3-story special concentric braced frame building in California. The bedrock is very shallow at the site, so the grade beams will bear on bedrock. The geotechnical engineer recommends that I use micropiles or rock anchors to resist uplift loads. My...
I am working on the design of a theater building. The building will be steel construction with concrete over metal floors and roof. The exterior walls will be non-bearing metal studs with cement plaster finish. The lateral system will be braced frames set inside the exterior walls.
At one area...
I am starting work on a new 3-story office building in Calif with braced frames in one direction and moment frames in the other direction. The floors will be lightweight concrete over metal deck.
Before I get too far in the design, I want to make sure I have a good handle on attaching the metal...
I have a project under construction in which the batch plant closed and they ran out of concrete while pouring a large footing. I have a 18"x24" conc column that sits on what was supposed to be a 12' sq x 2'-6" thick footing. The footing as poured is only 2'-0" thick. I checked the 2'-0" thick...
I am curious how other engineers connect wide-flanged beams to HSS columns for a simple shear bolted connection? Our office policy has always been to slot the column and install a through plate connection, but I know this is expensive. I talked to one fabricator and he said slotting the column...
I am working on the design of a 3-story light gage steel and structural steel building in Northern Calif. The stairs are steel and tied into the lateral system of the building. What do I design the connection of the stairs to the building for?
I do not think it would be an Fp calc since the...
I am designing a wood frame structure with non-parallel shear walls. I am trying to determine how to distribute forces to the skewed shear wall. Below is an example of what I think I can do:
On one line of resistance, I have a 10' long wall (plywood shear wall) at 0 degrees and another 10' long...
I am working on the design of a heavy timber truss with an arched bottom chord (30' radius). The architect would like to cut the bottom chord from a 8x18 or 8x20 to be an 8x14. The chords will be spliced at the center king post. Is this even possible? Or does it need to be glulam?
The loads in...
I am working on a project with a post-tensioned concrete podium slab over concrete shearwalls. I am trying to check the shear capacity of the slab to wall dowels, but I did not see anything in ACI. Should I be using Appendix D?
Thanks for any advice!
I have designed some concrete retaining walls that I am working on developing a control joint detail. Does anyone know of a product like a zip-strip, but for walls? What other products do you use at a control joint in a wall?
Thanks!
