A client of ours has a 2-story manufacturing facility that is primarily precast concrete construction. We noticed an unusual cracking pattern in one of their precast beams that is exposed in a stairwell. Analysis of the beam and design of a fix are out of scope at this time, but we want to do...
We have a project with an existing rectangular concrete tank that has a stainless steel lining (so concrete is not critical for tank being water-tight) and we needed to install a 6" pipe through the tank wall. We expected the contractor to core a small hole just above the tank floor through the...
We've been asked to analyze the effect of section loss in a 96" diameter exhaust duct with 1/4" walls that is suspended from the roof. I've hit a bit of a roadblock since AISC (chapter F8 in 13th edition) limits the scope of the chapter to round HSS sections that have a D/t of less than...
I have a unique situation that came up in the last week, that I'd appreciate some opinions on.
We have a wastewater tank that has bolted steel glass lined walls with a concrete floor. The slab was poured about a year ago, and there are several concrete spalls 1"-2" in diameter dispersed...
I'm working on an 1800 square foot single story CMU addition to an existing building. Since the existing building (built in the 1950's) is over the allowable height per IBC Table 503 (2009 IBC) for the construction type, we need a double fire wall that can't be tied to the existing building...
I'm curious what everyone's opinion is on this and what you typically specify for air entrainment specifically in warmer climates.
Most of the work I do is in colder climates in the northern midwest, so its a given that all concrete exposed to the elements will contain an air entrainment...
In our office here, some of our mechanical engineers are looking at purchasing software for analyzing mechanical pipe runs for thermal expansion (along with all the other hydraulic and gravity forces on the pipe). They are looking at purchasing Caesar II by Intergraph mostly, but they are all...
Does anyone have section properties for a C15x45 channel from 1935?
The AISC Rehab and Retrofit Guide doesn't cover channels, and the oldest Steel Manual I have access to is from 1946, which only has C15x33.9, C15x40 and C15x50 sections (identical to today's sections).
I'm designing an addition to a concrete wastewater tank that was built in 1999 and I have the original soils report from 99, where it reccomends using equivalent fluid pressures of 65 pcf above the water table and 95 pcf below (at rest). The tank is 17' deep of which 16' is buried. Problem is...
Does anyone know where I can find design values for "Maple Heart" Wood? I'm trying to check 3x8 planks (laid flat) for a construction load and can't find anything in the NDS manual or from an internet search. I'm not sure what grade the planks are, or even if this type of wood is usually...
Can A307 anchor bolts be bent, without a significant loss of strength? If there is a loss of strength, is it safe to use a portion of the full strength? The contractor installed several anchor bolts crooked (10-15 degrees from vertical). The anchors are 1.25" dia x 12" long cast-in anchors...
I need to check an existing steel joist roof built in 1961 for loads due to some new HVAC equipment. The joists are designated as 40LA18 and they span 68'-10". An old thread (thread507-74306) was posted back in 2003, and it sounds like some of you have information on this series.
Thanks,
Jason
I'm in the process of designing a very unique built-up steel section that will be loaded in combined axial compression and flexure. Imagine a steel plate about 48"x1/2", and the ends of the plate have flanges (18"x1/2") welded on one side of the plate only (so we now have sort of a 48"x18"...
Does anyone have information on old/obsolete steel sections? More specifically, I need section properties for beams from around 1930, called out similar to either "24C-76#" or "24CB @ 76#". These sections are not channels as the "C" might suggest. They look similar to wide flange sections...
I'm designing the concrete foundation for a metal circular tank. What are the advantage and disadvantages of using a membrane slab as defined in ACI 350-Appendix G? Supposedly the design philosophy is that the slab is flexible enough to take any differential settlement while still remaining...
