Recent content by pba

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...

plasgears, Did he become abusive and insulting before or after you started calling him a bastard? ;)

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...

Um, People love bagless vacuum cleaners because they work better than the ones with bags?

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...