rib raft foundation (raft foundation combined with beam)
rib raft foundation (raft foundation combined with beam)
(OP)
hello engtips users
i wanna ask what are the considerations of using this ribraft foundation thing?
what are the advantages and disadvantages?
what are some load applied on it?
how do we design the slab and the beam?
thank you.
http://files.engineering.com/getfile.aspx?folder=f...
i wanna ask what are the considerations of using this ribraft foundation thing?
what are the advantages and disadvantages?
what are some load applied on it?
how do we design the slab and the beam?
thank you.
http://files.engineering.com/getfile.aspx?folder=f...






RE: rib raft foundation (raft foundation combined with beam)
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: rib raft foundation (raft foundation combined with beam)
RE: rib raft foundation (raft foundation combined with beam)
RE: rib raft foundation (raft foundation combined with beam)
So the beams project neither below nor above the raft slab concrete? If so then I mostly agree with jayrod: little point to it. The only potential advantages that I could think of would be:
1) it might make for simpler analysis and detailing in some cases.
2) the beams could used to circumvent punching shear issues at the columns.
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: rib raft foundation (raft foundation combined with beam)
RE: rib raft foundation (raft foundation combined with beam)
note: sloof is a ground beam
RE: rib raft foundation (raft foundation combined with beam)
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: rib raft foundation (raft foundation combined with beam)
RE: rib raft foundation (raft foundation combined with beam)
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: rib raft foundation (raft foundation combined with beam)
RE: rib raft foundation (raft foundation combined with beam)
I would suggest that you approach your senior and tell him/her you are unsure how to approach this design and that you need help. No-one on this site has sufficient information on the project to give the guidance you are asking for. Your senior does, and also needs to know that you are unable to do the project you have been assigned.
RE: rib raft foundation (raft foundation combined with beam)
I can certainly guide you through the basic steps of a design based on the assumptions that I've made regarding your project if you wish. That may not be the wisest way to proceed however. As rapt mentioned, proceeding with a design assuming that I know enough about your project to guide you appropriately is a risky proposition. And I very much agree with him that good communication with your senior engineer is of great importance to the success of both this project and your development as an engineer in general.
Consider these questions which I do not presently know the answer to:
1) What's the superstructure here?
2) What are the site geotechnical recommendations?
3) What are those big grade beams for? Are they intended to iron out a differential settlement issues across the site? Are they to provide base rigidity for for a moment frame system (probably not if you're three stories below grade)? Are they simply to hold up the suspended, structural slab on grade?
4) Is the 300 slab really intended to be a suspended, structural slab on grade? If so, why is the soil good enough for pad footings at the columns but not good enough to support a grade supported slab on grade?
These are all questions that will impact your design and can surely be answered by your senior colleague.
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.