I have run into a situation where the contractor has installed 400 headed stud anchors to be 4" long with a 3" composite metal deck and 2" of concrete over the deck. This gives 1" projection over the metal deck. They were supposed to install 4 1/2" length to get the minimum 1 1/2" projection...
I have read in several articles that the difference between ordinary and intermediate reinforced masonry shear walls is that the vertical spacing must not exceed 48in oc. I am having trouble finding where it explicitly says this in the code. Can someone point me to the right code section? The...
I have always acted under the assumption that welded wire mesh was the same strength as rebar (60ksi). It came up recently that welded wire mesh also comes in higher strengths. My question is, what is the most common strength used for welded wire mesh and is it cost effective to go with the...
Has anyone had a chance to read through the ACI manual 544.6R-15? It was my understanding that ACI did not have any guides for the design of concrete reinforced with only fibers, but this new guide appears to allow you to design an elevated slab with steel fibers only.
Can anyone confirm that...
I have a contractor who has had some issues on a previous job with the concrete showing up at the site with a higher slump then specified and allowed the pour to continue anyways. On this previous job, the concrete strengths came out low consistently across many of the pours and caused a bunch...
I have an open structure (gable roof) with slope of 53 degrees. Per ASCE 7-05 table 6-18B, it only provides pressures for the roof up to 45 degrees. What pressure would you use for slopes greater than 45? I would consider using wall pressures, except for an open structure ASCE does not define...
I have a situation where the contractor has set the anchor bolts for a base plate in a 9" by 9" grid vs the 13" that it was supposed to be. I have checked the anchor bolts and have determined that it can still work as long as we expand the base plate some to increase the moment arm (these base...
So I have an existing LG Stud wall that is curved around a stair case. The architect wants to cut and remove the lower portion of the wall to open up the second floor. What we have come up with is to attach several plies of plywood to the existing curved stud wall just above where they are going...
So I am just curious as to what people typically specify and what the reasoning is behind the methods used, but I have worked for two companies and the first one would always provide Wide Flange beams at the column lines for steel roof and floors and then infill with joists between them. My new...
I feel like I am missing something. I have run the calculations on a 3'-6" tall handrail post several times in this delusional hope that the calculations will come out differently but sure enough, they don't. The calcs point to needing a 1-1/2" STD handrail post (which has an O.D. of 1.9") to...
Has anyone ever seen or designed a steel monoslope roof structure with wide flange rafters below wide flange purlins and braced using a plywood deck? I am working on a custom home and this is how the owner has detailed it out and I am not sure exactly where to go for the capacity (in lbs/ft) for...
I am trying to determine what exactly the stress reversal is in a steel joist. When I use Vulcraft's shear diagram assistant program on their website, it gives me the stress reversal as a %. I want to be able to calculate that percentage on my own but can't find anywhere that tells me exactly...
So I have a Geotech Engineer who has given me an uplift capacity equation for the drilled piers on a project I am working on. The equation is:
Qu=5.5*Cu*(B-b)
Qu=ultimate uplift capacity, pounds
cu=average soil shear strength above the footing (use Cu=900psf)
B=underream diameter, ft
b= shaft...
When designing a slab on grade with drilled piers on expansive soils I have always been taught that you add enough select fill (Per the Geotech engineer) to reduce the soils PVR to 1.0 inch for it to be acceptable. Does anyone know where this acceptance criteria came from? Is it accurate?
In ACI 318-11 Section 14.8.2.4, it gives a requirement that the nominal moment capacity of a concrete wall shall be greater than the cracking moment of that wall. My question is that if all of my factored loads (Pu, Mu, Vu) are all lower than the allowable nominal values (Pn, Mn, Vn) and my...
I have a project where the manufacturer has specified a roof truss with a span greater than 60'-0". I seem to recall reading somewhere that when a roof truss exceeds 40'-0" it requires some kind of special rigging as well as a design engineer on site during erection. Does anyone know about this...
Does anyone know where you can find information on the shear capacity of a cracked reinforced flat plate slab? I don't believe there is any capacity with no shear reinforcement, but I just wanted to see if anyone had more knowledge on this than me.
Criteria:
Existing 10" slab
30'-0" x 30'-0"...
I have been given two options for the foundation of a PEMB (Pre-Engineered Metal Building) expansion onto an existing church. The options are a Post-Tension Slab-On-Grade and the other is the Building Research Advisory Board (BRAB) procedure outlined in their report. Typically for PEMB...
So I am working on the design of a blast-resistant building at a chemical plant, however I have not been given much information to begin my design. Does anyone know a typical peak or incident side-on overpressure (in psi) that would be used for this type of design. The design guides I have...
I have a client that has bought an existing structure with a two way flat plate slab conventionally reinforced with drop caps at the columns. The required loading for the new occupancy has resulted in a higher punching shear load then the current capacity. As of now, it will be very difficult if...
