Are you sure that is concrete on top? Could be self levelling screed, it is difficult to tell the difference with an untrained eye.
I expect those joist would have a visible sage with that amount of weight on it.
This goes back to tilt up and precast panels which are mostly singularly reinforced.
There has been testing over the years to prove that they are more robust than you may think.
Not all buildings are affected by the earthquake provisions.
In most codes beams shear is given a higher factor of safety than slab shear I believe the theory is that you are unlikely to have poor concrete across the full shear width of a slab whereas it is more likely on a narrow beam.
Most serious failures do not occur because the member is not quite strong enough, most occur because of something fundamentally wrong with the structural scheme or with the way it has been installed.
Conservatism will not negate this only checking of the design will negate this.
Even with...
6m is quite tall for a single floor so you would probably need 600mm diameter secant or quite chunky sheet piles.
Also look at the available space you have to surrounding structures and the required clearance you need for each.
Both options would need to be propped during construction though I...
Rapt,
Thanks, that was the direction that I was thinking and was concerned about, particularly for a pt slab above.
We have resolved the main issue of the moments by letting the transfer slab sag under the weight of the wet concrete. This is not perfect but I had three structural consultants...
Thanks,
That is about where I am coming from.
The transfer beam that I am looking at has a 2.25 inch total deflection in a 42foot span with the coluumns supporting the middle of the PT slab above. The design consultants just dont get my concerns, they keep stating that it is 'to code' but the...
What limits would people be looking to design a transfer beam that supports a concrete column and post tensioned flat slab at the level above and a reinforced concrete slab at its wown level. I have a consultant that has designed a transfer beam that is no stiffer than your average floor beam...
englisa,
I think you are missing the point here.
Calculate the deflection from a one pound point load and the inverse gives you a spring constant. From that you can determine how much force is exerted for each mm of deflection and then calculate the total impulse required and therefore tha...
Lutfi,
Actually, steel loses its strength faster than large sections of timber char so sometimes the mental picture of wood burning is counterintuitive to the reality.
What happens if you get oscillations in the cables and those on one side go a little slack for a split second, what stops the rod from rotating and the cables slipping off?
This is not a detail that I would feel comfortable with.
rheim,
The atc put out a guidance note on timber vibration though I am not sure how helpful it would be.
The fundamental are still the same for all materials so I suggest that you research vibration in general to get a handle on things.
Modern research has shown that the key is usually the...
