Is it practical to slope a steel framed roof (bar joists w/ wide flange girders) both parallel and perpendicular to the joists? In other words the joists would be at a slope parallel to their length while also having a cant. The slopes range from 1/4” to 1/2” per foot. My concern is that this...
I have been tasked with analyzing an existing composite floor system to support operable partitions Footprint is around 80x100 with composte bar joists spanning the 80’ dimensions between wf girders. They are wanting to add a significant amount of partitions, around 20 kips total, that will be...
My firm works on a lot of foundation designs in expansive soils for residential and small commercial structures. Up to this point we have always used the BRAB methodology to design our slabs. I am currently reviewing our design process and working on incorporating the WRI method into our design...
I’m looking at doing steel girder roof trusses to frame a 70’x200’ structure. The trusses will be spanning the 70’ dimension, probably 5’ or 6’ to 7’ in depth, and will be spaced at about 20’ on center. The configuration resembles a typical bar joist but with 2 HSS 12x6 top and bottom chords...
Has anyone used bracing similar to what’s shown in the attached image? They call it unsymmetrical portal bracing. I am looking at using this configuration to work around a door. I’m a little uncomfortable having that pinned joint where all of the braces meet under compression and subject to...
I have a foundation on void forms that is a one-way slab system, rated for HS-20 loading. There are grade beams supporting the slab that coincide with 8" deep trench drains running parallel to and centered on the beam line. In order to keep slab continuity, I am bending the top slab steel down...
One of the details in the IRC specifies that shelf angles for masonry veneer be atteched into 2-2x studs with 7/16” lag bolts. My intuition is telling me that this detail sucks since it seems that if the lag bolts coincide with joints in the plies it’s bad news. Usually for shelf angles I will...
I’m working on a project with the following note in the steel election specification:
Snug-tighten anchor rods after supported members have been positioned and plumbed. Do not remove wedges or shims but, if protruding, cut off flush with edge of plate before packing with grout.
The contractor...
I am working on a mid-size wood framed structure, 2x6 stud walls and gable roof trusses. It's all single story and in a relatively high wind zone. I have base shear and uplift values on my walls maxing out at around 400 plf. The lateral system is a mix of segmented and perforated shearwalls, the...
Let's say I have a commercial box building, 55' wide x 150' long x 20' high. Steel frame, bar joists with metal deck clear spanning the 55' with wide flange girders and 6" tube columns and light gauge infill. I have chevron bracing on both 55' walls and on one of the 150' walls. The front end is...
I have a client who wants to add an additional 8' in height to their existing water tank. The existing tank has an inside diameter of 22' with 12" thick walls and has a depth of 10'-6". I have not seen the tank empty so I do not know what the conditions are at the bottom or what kind of footing...
I am designing a 4-part milti-story steel frame with composite deck, buildings range from 3-5 stories, largest columns are W14x120. The lateral bracing mainly consists of chevron frames, using base plates recessed 8" into concrete at the foundation. The foundation is a one-way slab over a 6'...
