Recent content by jrfroe

There may be something to this. The stairwell this is in does get cold in the winter. I don't think they have heating in the stairwell and the wall in the picture is an exterior wall. I'm not yet convinced its not a buckle knowing the location is protected by the nearby stairway. If its due...

Thanks... If its not wise to take out the column, I would for sure want to replace it since it seems like it is also twisted slightly. I'm pretty sure the "buckle" isn't impact damage since its in a stairwell underneath a flight of stairs at a location that isn't accessible to anything that...

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...

steveh49 - Thats good advice... Luckily this a contractor we have a long-standing and good relationship with, which makes things like this so much easier to deal with. We will likely split the cost of the repair (which isn't a large cost by any means). They're able to install the dowels as...

Thanks everyone for your helping me chew on this for a bit! Much appreciated!

SlideRuleEra - Its 12" thick with #6@12" each way & each face... I'm proposing to add in dowels of the same size and spacing with an additional dowel lined up just outside the edge of the manway above.

retired13 - correct... not cantilevered since it does have a roof bracing the top of the wall... I agree that its not a big problem for the tank as a whole as its a small section of the tank wall, but I'd expect extensive cracking locally in the area when the tank is re-filled (without any...

IRstuff - The new pipe would be centered in the new opening. We would fill around the pipe with concrete after installing rebar dowels.

JAE - the manway has an embedded steel frame around it... There are no nearby out-of-plane concrete walls. The flexural stresses in this area are almost exclusively in the vertical direction (stressing the inside layer of reinforcing)

retired13 - the inner stainless steel is only a lining... not structural... the wall the hole was cut in is roughly 50' long and 12' high.

Miningman - That is indeed part of the problem... they were not given clear drawings showing what was expected, so we are also partly to blame (which complicates things a bit). However, neither myself or any of our structural engineers were made aware of this project until after this hole was cut.

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...

Good point with the ASME code and a duct running hot. This duct runs around 150 to 170 degrees F. I'll look into the B&PV code and the SMACNA standard. Thanks, for the responses!

I just had a thought... Since I'm not that far outside the D/t limit in AISC F8, I could assume the steel is a lower yield strength than it actually is in order to force the limit to be met. I would think this would be a conservative way to analyze the duct if the difference is small... do you...

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...