This posting is continuation of Post #16
This is an old good book.
This book talk about seismic code of UBC 1985, UBC 1991 & UBC 1994.
There example about flat slab - column frame in this book for low & lower medium seismic hazard area.
I think iceman84's answer should be added with :
flat slab - column frame is for low - lower_medium seismic hazard area only
For tall building with flat-plate in medium & high seismic hazard area, the use of structural wall is a must & not use column is no problem.
But, generally ( in real projects ) it use both column & wall for lateral load resistant system.
Things about structural wall in ACI 318/318M 2008
# ONE
New in ACI 318/318M 2008 about requirements for reinforcement in Special moment Frame & Special Structural Wall :
Use of longitudinal reinforcement with strength substantially higher than that assumed in design will lead to high shear & bond stress at the time of development of yield moments.
This condition can cause brittle failure in shear & bond, & should be avoided.
Ceiling ( max limit ) is placed on the actual yield strength of the steel.
Actual yield strength based on mill test does not exceeded "fy" by more than 125 MPa or 18000 psi.
#TWO
New in ACI 318/318M 2008 about flat_slab - column
Read chapter 21.3.6.8 about shear design requirements for flat_slab - column joint in intermediate moment frame
#THREE
Special RC Wall vs Ordinary RC Wall in ACI 318/318M 2008
$$$
[ SPECIAL RC WALL ] Rho min for vertical reinforcement = 0.0025
[ ORDINARY RC WALL - US Units ] Rho min for vertical reinforcement -->
= 0.0012 for No 5 bar or smaller, fy not less 60000 psi
= 0.0015 for larger than No 5 bar, fy not less 60000 psi
[ ORDINARY RC WALL - Metric Units ] Rho min for vertical reinforcement -->
= 0.0012 for bar not larger than No 16, fy not less 420 MPa
= 0.0015 for other bar ( larger than No 16 ), fy not less 420 MPa
$$$
[ SPECIAL RC WALL ] Rho min for horizontal reinforcement = 0.0025
[ ORDINARY RC WALL - US Units ] Rho min for horizontal reinforcement -->
= 0.002 for No 5 bar or smaller, fy not less 60000 psi
= 0.0025 for larger than No 5 bar, fy not less 60000 psi
[ ORDINARY RC WALL - Metric Units ] Rho min for horizontal reinforcement -->
= 0.002 for bar not larger than No 16, fy not less 420 MPa
= 0.0025 for other bar ( larger than No 16 ), fy not less 420 MPa
I hope my review useful for all of you.
Thx
Quote:iceman84I think iceman84 answer based on Ghosh's book " Design of Concrete Building for Earthquake & Wind Forces" 2nd Edition, 1995
It is recommended, but not mandatory to use structural walls to resist lateral forces. The joints should be checked, so that no plastic deformation appears there.
This is an old good book.
This book talk about seismic code of UBC 1985, UBC 1991 & UBC 1994.
There example about flat slab - column frame in this book for low & lower medium seismic hazard area.
I think iceman84's answer should be added with :
flat slab - column frame is for low - lower_medium seismic hazard area only
For tall building with flat-plate in medium & high seismic hazard area, the use of structural wall is a must & not use column is no problem.
But, generally ( in real projects ) it use both column & wall for lateral load resistant system.
Things about structural wall in ACI 318/318M 2008
# ONE
New in ACI 318/318M 2008 about requirements for reinforcement in Special moment Frame & Special Structural Wall :
Use of longitudinal reinforcement with strength substantially higher than that assumed in design will lead to high shear & bond stress at the time of development of yield moments.
This condition can cause brittle failure in shear & bond, & should be avoided.
Ceiling ( max limit ) is placed on the actual yield strength of the steel.
Actual yield strength based on mill test does not exceeded "fy" by more than 125 MPa or 18000 psi.
#TWO
New in ACI 318/318M 2008 about flat_slab - column
Read chapter 21.3.6.8 about shear design requirements for flat_slab - column joint in intermediate moment frame
#THREE
Special RC Wall vs Ordinary RC Wall in ACI 318/318M 2008
$$$
[ SPECIAL RC WALL ] Rho min for vertical reinforcement = 0.0025
[ ORDINARY RC WALL - US Units ] Rho min for vertical reinforcement -->
= 0.0012 for No 5 bar or smaller, fy not less 60000 psi
= 0.0015 for larger than No 5 bar, fy not less 60000 psi
[ ORDINARY RC WALL - Metric Units ] Rho min for vertical reinforcement -->
= 0.0012 for bar not larger than No 16, fy not less 420 MPa
= 0.0015 for other bar ( larger than No 16 ), fy not less 420 MPa
$$$
[ SPECIAL RC WALL ] Rho min for horizontal reinforcement = 0.0025
[ ORDINARY RC WALL - US Units ] Rho min for horizontal reinforcement -->
= 0.002 for No 5 bar or smaller, fy not less 60000 psi
= 0.0025 for larger than No 5 bar, fy not less 60000 psi
[ ORDINARY RC WALL - Metric Units ] Rho min for horizontal reinforcement -->
= 0.002 for bar not larger than No 16, fy not less 420 MPa
= 0.0025 for other bar ( larger than No 16 ), fy not less 420 MPa
I hope my review useful for all of you.
Thx