Now this thread has become unexpectedly interesting and useful...
God I love Eng-Tips!
I've heard both this and the "reduce by XX percentage" argument from both Geotechs and Structurals for many, many years...
So: Which is it? Should we combat the accelerated initial settlement with a...
In my opinion, the same type of foundation is always best. So yes, I would use strip foundation on the new addition. As you can see above, there are very good engineers who differ in their advice and approach...
The approach we use is to match foundation types, ensure there is no backfill in...
Gotta admit I missed that entirely: I know lots of places have been pile foundations forever; I made an ASS out of U and ME (assume)...
Jayrod has the comment of the thread; this is a pretty serious issue if you have mixed systems. I was assuming that you were connecting two of the same type...
While I agree with Kootk that this isn't strictly limited by code, the Geotech gang have some great guidelines.
I use the Canadian Foundation Engineering Manual (2006) which has a great bit of guidance for dealing with this on P. 178. Table 11.11.
Generally speaking, if you aren't comfortable...
Well then; I've learnt something today! Thanks all... Definitely something to keep an eye on. Seems to affect the fabricators most, but we need to ensure that these zones are suitably protected.
S16 doesn't appear to have instructions or guidance for showing this; are you simply showing the...
I don't see any reason to have a minimum distance, if you're using a Complete Penetration Joint. That's the point; it is complete and should be equal in performance to the original.
I'm entirely ready to be corrected and learn something today... The analogy in a reinforced concrete frame...
Planc: You're confusing drying/shrinkage cracks which have their backside (bottom) restrained, ie: slab on grade, with suspended slab behaviours... Hokie's dead on.
I agree with Kootk, if you are dealing with short or non-existent pedestals.
Again, this depends on the geometry. I've designed numerous such buildings, particularly during my time in New Zealand, but also been the forensic engineer on the collapse of two and the required demolition of a...
You didn't answer about the source of the water...
The water source must be addressed. Holding the water inside the slab is a really, really bad idea. That eliminates your option 1. Option 2 is expensive and potentially unnecessary. Option 3 is only going to shift the cracks to another...
JStructsteel: It would shock me if the manufacturer allowed this hole without any decrease in capacity. For many this would be a 100% warranty destroyed modification of their product.
Middle third of the middle third is typical. We even have one manufacturer who specifically proscribes holes...
Well that is surprising... From the plans that would not be a flexural crack, but the pattern really looked like a classic yield line pattern.
Regarding the membrane: No, only areas expected to have moisture. Did my eyes deceive me, or is there water dripping through?
Honestly a very strange...
Reminds me of a disaster that happened while I was still in University: Westray.
In that the Royal Inquiry included my favourite quote about the "business" of Engineering:
"The Westray story is a complex mosaic of actions, omissions, mistakes, incompetence, apathy, cynicism, stupidity and...
Slab patterns can be "read" to tell whether they are flexurally governed or majority shrinkage in nature. There is no such thing as a crack that is wholly one and not at all involving the other.
You should look at the Johansen yield lines; they are very simple and predictable and show the...
All that matters is the anchoring.
You may be having a St. Venant's issue, as in: Stroking out between local versus global. Locally the pan must be developing composite action with the concrete, globally the elements must be anchored against sliding...
Sketch?
I believe the weld strength is based on the old standards used in the US, but this is only my belief. I'll be very interested to see other responses. You may need some of our "long in the tooth" members to chime in. If memory serves, the formula for this should be 0.66 Fu.
My copy of Design...
This depends on the proportions, in my experience....
Keep your shear versus flexural transition in mind; 2.25 +/- 0.25
Definitely time for a sketch to be posted.
My comment is based on this 2" thick pad and equipment placed onto the one day old 8" thick floor.
I will be interested to see other replies, but this makes me very, very nervous. Just like durability correlates well with compressive strength but is a different parameter, strength does not...
The link: https://www.youtube.com/watch?v=QVQdF1s1SJA
A very interesting chat about MWFRS design and serviceability. The discussion about ductility in the ultimate strength design is in the commentary Q&A at the end.
If you don't already receive notice of ATC's free webinars, I would...
Extremely interesting that this came up in today's ATC online webinar "ATC Design Guide 3, Serviceability Design of Tall Buildings Under Wind".
Reflected my comments. Openly discussed that ductility is a reasonable approach, and a likely future in wind design. "Probably being too conservative...
