Dear all CivilEA member
I delay continue my review about "IBC 2000 & its related" because I found more interesting topic.
You can read here :
The thread about "Seismic Design for Flat Plate System"
In this posting I focus on the flat plate stuff first & I will review the seismic design of it in next posting.
FLAT PLATE
When you design flat plate, you must check "shear stuff" below :
1) check "wide-beam action shear"
2) check "two-way action shear"
3) check "moment-shear transfer at slab-column connection"
Simply in all 3 checking above must : (phi) x Vc > Vu
If you use ACI 318 2008, phi for shear = 0.75
"Wide-beam action shear"
The investigation is made at the critical section at distance "d" from face of column support
For this checking Vc use equation 11.3 of ACI 318 2008
"Two-way action shear"
The investigation is made at the critical section "bo" located at "d/2" from column perimeter
For this checking Vc use 3 equations about "two-way action shear" in ACI 318 2008
You must be careful, you must know when you must use all those 3 equations & when you only use the third equation.
If Vu > (phi) x Vc in one or more of 3 shear checking above, you must increase the shear strength of your flat plate with 1 of several methods below :
1) increase shear strength by increasing "strength ( fc' ) of your flat plate
2) increase shear strength by increasing slab thickness at column support with drop panels
3) increase shear strength by adding shear bar reinforcement
4) increase shear strength by adding steel I shapes
5) increase shear strength by adding headed shear stud reinforcement
(*) Doing first method above ( increasing "strength ( fc' ) ), you must do cost analysis carefully to avoid cost inefficiency if you choose this method.
Because you increase "strength ( fc' ) in all over flat plate, with fact we just need increasing of strength in the critical section only.
(*) I think the most simplest/easiest way is adding "drop panels" & among method 3 until 5 above, adding shear bar reinforcement is easier.
If you use "US units" it will be no problem when you use US concrete book such as PCA book & others.
You can instantly apply it for your design.
BUT, if you use "metric units" be careful, you must verify first the formula you will use from ACI 318M, some formulas / equations are different between in "US units" & in "metric units".
I will continue this topic in my next posting.
I promise after this topic end, I will continue my review about "IBC 2000 & its related"
I will continue my review maybe around 4 or 5 Jan 2011 ( 2 or 3 days ahead ) because I still doing my thesis & for several days I will totally focus on my thesis.
I hope all of you can understand.
I hope my review useful for all of you
Thx
I delay continue my review about "IBC 2000 & its related" because I found more interesting topic.
You can read here :
Code:
***************************************
Content of this section is hidden, You must be registered and activate your account to see this content. See this link to read how you can remove this limitation:
http://forum.civilea.com/thread-27464.html
***************************************
In this posting I focus on the flat plate stuff first & I will review the seismic design of it in next posting.
FLAT PLATE
When you design flat plate, you must check "shear stuff" below :
1) check "wide-beam action shear"
2) check "two-way action shear"
3) check "moment-shear transfer at slab-column connection"
Simply in all 3 checking above must : (phi) x Vc > Vu
If you use ACI 318 2008, phi for shear = 0.75
"Wide-beam action shear"
The investigation is made at the critical section at distance "d" from face of column support
For this checking Vc use equation 11.3 of ACI 318 2008
"Two-way action shear"
The investigation is made at the critical section "bo" located at "d/2" from column perimeter
For this checking Vc use 3 equations about "two-way action shear" in ACI 318 2008
You must be careful, you must know when you must use all those 3 equations & when you only use the third equation.
If Vu > (phi) x Vc in one or more of 3 shear checking above, you must increase the shear strength of your flat plate with 1 of several methods below :
1) increase shear strength by increasing "strength ( fc' ) of your flat plate
2) increase shear strength by increasing slab thickness at column support with drop panels
3) increase shear strength by adding shear bar reinforcement
4) increase shear strength by adding steel I shapes
5) increase shear strength by adding headed shear stud reinforcement
(*) Doing first method above ( increasing "strength ( fc' ) ), you must do cost analysis carefully to avoid cost inefficiency if you choose this method.
Because you increase "strength ( fc' ) in all over flat plate, with fact we just need increasing of strength in the critical section only.
(*) I think the most simplest/easiest way is adding "drop panels" & among method 3 until 5 above, adding shear bar reinforcement is easier.
If you use "US units" it will be no problem when you use US concrete book such as PCA book & others.
You can instantly apply it for your design.
BUT, if you use "metric units" be careful, you must verify first the formula you will use from ACI 318M, some formulas / equations are different between in "US units" & in "metric units".
I will continue this topic in my next posting.
I promise after this topic end, I will continue my review about "IBC 2000 & its related"
I will continue my review maybe around 4 or 5 Jan 2011 ( 2 or 3 days ahead ) because I still doing my thesis & for several days I will totally focus on my thesis.
I hope all of you can understand.
I hope my review useful for all of you
Thx