Thank you all for your responses.
The AHJ agreed that we do not need to evaluate the entire roof for the new 50 PSF ground snow load.
In all honesty, i believe we may be removing a nominal load from the roof as we believe it was designed to be ballasted (we cannot really confirm that). I had...
We have a project where we are adding new RTU's and replacing the existing roof with increased insulation. During our analysis of the roof for the new RTU's, it was determined that the ground snow load increased from 40 PSF to 50PSF in the mid 2000's (we are in a site specific location). The...
I'm working on a project where I received structural calculations for a piece of equipment which is around 10'x12'x35' tall and weighs approximately 100K. We are responsible for the base plate design (a bit unusual), anchorage and foundation. After reviewing the calculations, I discovered that...
Hokie,
thanks for that reference. That is just what I was looking for. tough to swallow... but just what I was looking for.
Just wanted to mention that in Laman's paper I'm pretty sure he used the Third edition (dark blue lrfd book). He included his fortran which has LP=300*Ry/SQRT(fy) which...
I believe the value of Lp as defined in section F4-7 of the black book should be comparable to Lb as defined in F1-2 in the green book. Both of them essentially maximize the allowable moment capacity and removed the lateral torsional requirement.
First, this design is for a replacement of an existing section for a runway beam which is starting to fail (the original is concrete encased and the concrete is showing preliminary signs of failure). The original design was modified some years ago to include a cap channel for lateral stability...
That's about what I'm getting JAE. Thanks for the reply.
It just seems odd that AISC published a design guide in 2004 with Lp over 20', but then literally the next year published new codes that cut it in half. I still see a lot of people referring to the design guide 7 for crane girder design...
I'm currently designing the runway beams for a 26 Ton crane with columns at 20'. I'm having significant difficulty trying to determine the best way to design for lateral torsional buckling. For the purposes of this discussion, I will be looking at a W30x116 with a C15x33.9 Cap Channel with using...
I have a project where I have somewhat large shear forces going into W10 beams. We are trying to control depth and are restricted to using W10's or less. I am hoping to use a W10-W10 connection, however due to flexural yielding, flexural rupture, and local web buckling the connections are not...
IMO, I wouldn't have done any work until I notified the owner that this was an additional service and they agreed. Your contract is with the owner (I'm assuming), not with the contractor. Therefore, the contractor doesn't pay you directly. As people have noted above, the owner pays you and the...
I'm the EOR for a small one story building where the contractor has installed the anchor rods slightly off from where they should be. AISC code of standard practice indicates that anchor rods should be placed within 1/8" in any bolt group and within 1/4" between columns. For a project of 48...
I recently got a call from a contractor who mistakenly installed 3/4" anchor rods where there should have been 1 1/2". Due to reduced loads during VE, the 3/4" anchor rods actually work on a 20"x22" pier however they will not work on a 20"x28" pier with the same bolt spacing, embedment depth...
dik,
I have looked into Wilson, but they provide no loading information. I have felt uneasy using something that isn't approved by ACI or tested in accordance with 355. When you used the corrugated pipe (this sounds like the detail that they want to use), what is your assumed load path? With...
I'm working on the foundation design for various industrial storage tanks with some significant uplift/moments (some are 60' tall and about 12' in diameter) and a tall exhaust stack which is about 6' in diameter and over 100' tall. As you can imagine, uplift is a significant concern. The...
