two way rib system question

[alshaiji]

Hello all
Here is the deal. I have a chem. Lab roof that is 15mx13.2m. the lab is column free and the roof carries the offices in the above floor. Go to the URL below to view a plan of the Chem lab.

http://malshaiji.topcities.com/room/chemlab.htm

My questions are:
How can you establish the depth of the ribs according to deflection requirements and is there any ACI refrence?
How would you calculate the self weight of such system after you establish all dimensions needed (depth, spacing, and beam thicknesses)?

I hope my case is clear to you all
alshaiji

 

[jheidt2543]

It looks to me like you want to use a metal pan forming system. These are all proprietary systems and you should go to the manufacturer for their load and deflection tables. They would be able to give you all that information.

 

[alshaiji]

jheidt2543
First , I want to thank you for your reply. I have contacted some of the manufacurers here in Kuwait City and none of them have provided me with such info. all they say is "you specify the size and we will make it for you".

let me address the question to you and all the readers in anotherway.
how can you calculate the deflection in a waffle slab or the two way system i have provided the link for?


Thank you all

 

[vish57]

As a first trial use a normal two way solid slab design moment coef for the design. Use the same span/effective depth as for solid slabs for checking the deflections. Refer BS 8100 for coef. To refine your design use a stadd gris analysis.

 

[alshaiji]

vish57
thank you for your help. i will try that approach and see how it goes.
alshaiji