This is an apparently simple question which is proving difficult to get an answer to!
We have some platework under stress at an elevated temperature. Our mechanical engineer has given an allowable stress value based on an ASME code assuming steel grade A656 - which I think is an ASTM...
I must confess that when I first posted, I'd only looked at the first photo. I now see that there are two and a diagramme showing where the problem occurs - Well done Gyroman10.
If I'm now viewing things correctly the floor tiles have lifted along the length of a first interior beam position...
Thanks MotorVib,
Currently we have suggested low alloy steel to European specification with Charpy impact testing at -45. This should be similar to the ASTM standards.
Part of my reasoning in asking the original question was that AISC 13th Ed does not seem (on a casual read) to contain any...
For passive resistance to develop may require significant movement of the ground. - This would crack the concrete and allow the water to escape...
Even if the soil is very stiff it only contributes the the stiffness at the wall/slab interface - you still have the stiffnesses of the slab abd...
You don't say how old the building is or how long that flooring had been in place.
Also where are the joints in the finishes? There is a possibility that this is simply due to movement stresses within the finishes being released due to one tile de-bonding and then propogating across the floor...
Two questions:
We have a project in Russia which will have exposed steelwork and winter temperatures of -45 degree celsius. - What type of steel would you use?
Given the steel grade what special designs/techniques would you use in the connections to ensure that brittle fracture did not occur?
Thanks folks.
The large deflection comment is certainly worth looking at. Do you have any idea what would constitute a "large" deflection? I might just change to a very thick plate and re-run the numbers.
Agreed the 1000x200 plate should be like a 200 beam at the centre. I can of course do...
I don't know of any codes, but we specify at least 1m above cut off level. We then require the contractor to submit proposals on how to remove that concrete safely. Currently hydraulic munchers seem to be used most often. There are proprietary techniques available to remove the concrete in...
Structural Joe,
You are doing the right thing by getting an opinion from the building department.
Dik is also correct in that you should check dynamic effects. This is a very real problem and is especially so on long spans - which I'm guessing you now have. At the very least you should check...
Folks,
This is a theory question rather than an actual problem.
Some background - The company I work for has an old design guide for design of air ducting. The formula for plate stress under uniform loading is given as: fb = (K1 Q X^2)/t^2
Where fb is plate stress, K1 is a factor relating to...
Good start.
Points 1 and 2 are material specific?
3 - Agreed. In UK we have a limit state code (similar to LRFD) The section properties are given in a separate document (Blue Book) which can readily be used for simple cross checks. Checking designs could really do with a whole topic of its...
Another option of course would be to remove the slab abd replace it with one desiged for your new loading and arranagement - That should be suitably expensive for the Architect to reconsider...
Clansman,
I'm guessing this is a crane operating in a single bay steel portal frame building. For a 150 ton crane (overhead travelling type), I'd go with Hokie66 and use separate columns to support the gantry beams and brace between them. You don't say how long the building is but...
This really is somthing I have no experience of - so I may be totally off beam.
Can you fit stress gauges to the frame before testing? As has been said, failure is likely to occur at a connection and these are known to be damaged. You might get some good correlation to theoretical behaviour...
It is entirely possible that the Senior Engineer's relaxed attitude was a front in order to help protect his companies position.
It sounds to me as if Virmat is taking the failures in this calculation rather too personally. A detached and professional attitude is needed.
Basic load path...
Good document from Crossframe!
Withour better information I have tended to use 150kg/m3. (I think that is 430 lbs/yd3).
Once I have more idea of the actual members then I fine tune the quantities.
mrpid's approach will underestimate the actual steel weight as it makes no allowance for laps...
I've had two instances of contractor's filling cavities between blockwork leaves with liquid concrete without phasing it in lifts.
The pressures from wet concrete can be significantly higher than those from the ground. Insist that the work is done in lifts, not all at once.
Use a drier...
JIS sections are usually called out as depth x breadth x flange thickness. Tees are confusing we called off in the same way as beams. My JIS tables have two sections at 125 x 125 with 8 or 9mm flanges. If you wanted to be even more specific you could call out the actual size 124 x 124 x 8 TEE...
