limit state
TRANSCRIPT
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LIMIT STATE METHODOF DESIGN OF
REINFORCED CONCRETE
STRUCTURES
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SCOPE(LIMIT STATE METHOD)
1.VARIOUS LIMIT STATES, DESIGN VALUES, SAFETYFACTORS.
2.LIMIT STATE OF COLLAPSE ITS APPLICATIONSTO DIFFERENT STRUCTURAL MEMBERS.
3.LIMIT STATE OF SERVICEABILITY.
4.PROVISIONS OF IS 45.
5.DESIGN AIDS SP 1
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MAIN MENU
G!"!#$%
&'#"* S+#! M!+-'
U%+/$+! L'$ M!+-'
L/+ S+$+! M!+-'
M!+-' '0 D!*"
Exit
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GENERAL
C% !"*"!!#"* +#+#! $#! $ '/"$+'"'0 +#+#$% !%!/!"+ !$/, '%/", %$,0''+"* !+.
D! +' !+!#"$% %'$ '" +-! +#+#!,0'#! $#! *!"!#$+! " +-!! !%!/!"+ 6--$! !""* $" -!$#. A$% 0'#! $#! $%'*!"!#$+! " '/! !%!/!"+.
D!*" "'%! 7#'"* $ /!/!# '0 $+$%! 8! $" /$+!#$% +' 6+-+$" +-!!0'#!.
Main Menu
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METHODS OF DESIGN
T-!'#!+$%
Main Menu
($) &'#"* S+#! M!+-'
() U%+/$+! L'$ M!+-'
() L/+ S+$+! M!+-'
E7!#/!"+$%
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&OR9ING STRESS METHOD
T- /!+-' $/! +-$+ '+- '"#!+! $"+!!%$+ +'*!+-!# $" $#! !%$+$+$%% +$*!.
I+ $'7+ 7!#/%! +#!! 6-- $#!
!#! : $77%:"* $ 0$+'# '0 $0!+: +' +-!%+/$+! +#!"*+- '0 +-! /$+!#$%. T-! 0$+'#'0 $0!+: 0'# '"#!+! 3 $" 0'# +!!% + 1.;.
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STRESS=STRAIN DIAGRAMS FOR CONCRETEAND STEEL
O
A
BC
Concrete Mild Steel (Fe 250) HYS Bar! (Fe "#5)
OC L"!$# CA E%$+ R$"*! AB P%$+ R$"*!
&S M!+-' '"0"! +!%0 +' +-! %"!$# $" !%$+ #$"*! "'+- '"#!+! $" +!!%.
I"$#$! " !*" $/7+'" '#!##'# " $%%$+'".
I"$#$! " $!"* +-! 7#'7!#+!'0 +-! /$+!#$%.
D!*#!! '0 7!#'", ?$%+: '0
/$+!#$%,!!+'" '0 6'# !+.
P'%! !+!#'#$+'" '0 +-! +#+#!6+- +/!. <
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P#'$%+: $%%$+'" $#! '"! +$"* "+'$'"+ $%% +-! #$"'/ 0$+'# 6-- $" %!$ +'+-! %/+ +$+! +' $##! $+ +-! >
M$*"+! '0 %'$ $"* +-! /'+"0$'#$%! !00!+.
S+#!"*+- '0 /$+!#$%, +-!# ?$%+: $"$#$+'".
D!+!#'#$+'" 6+- 7$$*! '0 +/!. C'! -$ "+#'! -$#$+!#+ $%!!7!""* '" +-! 7!#'" '0 $+$ #!%$+"* +'"+!"+: '0 %'$"* $" +-! +#!"*+- '0 +-!/$+!#$%. I+ +-! $!7+$%! %/+ 0'# +-!
$0!+: $" !#!$%+: '0 $ +#+#! !0'#!0$%#!.
T-! +#+#! -'% ! $%! +' 6+-+$" $%%+-! %'$ %$%! +' $+ '" + +-#'*-'+ + %0!$+0:"* +-! %/+ '0 '%%$7! $ 6!%% $!#!$%+: (!0%!+'" $" #$"*).
T-! $/ +' $-!! $!7+$%! 7#'$%+!- +-$+ +-! +#+#! 6%% "'+ !'/! "0+ 0'#+-! ! 0'# 6-- + "+!"! .!. + 6%% "'+
#!$- + %/+ +$+!. <
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T-! !*" $! '" -$#$+!#+ $%!'0 /$+!#$% +#!"*+-$" +-! $77%! %'$
6-- +$! "+' $'"+ +-! $#$+'" " +-!+#!"*+- '0 +-! /$+!#$% $" +-! %'$ 6--$#! $77%! '" +-! +#+#!.
T-! -$#$+!#+ $%! $#! $! '"+$++$% $+$6-- $#! '+$"! 0#'/
0#!?!": +#+'" #!$%%! G$$"D+#+'" C#!.
B$%$"! S!+'"
C$! 2> U"!# #!"0'#! S!+'"
C$! 3> O!# R!"0'#! S!+'"
C$! 4> D'%: R!"0'#! S!+'"
5
0-002?0-@+;E!
0-002
0-"5+c,
>xu;30-">xu"xu;30-5xu
0-"2xu
C 3 0->7+c, xu &
3 0-@+ A!t
Cro!! Section Strain ia$ra% Stre!! ia$ra%
STRAIN AND STRESS DIAGRAMS
3 d D 0-"2xu
BALANCED SECTION
D!7+- '0 N!+#$% A 0'# B$%$"! S!+'" ( ,/$)
!#! 0#'/ >
y
u
f
Es
d
x
87.00055.0
0035.0max,
+
=
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L/+"* $%! '0 7!#!"+$*! '0 +!!% 0'#00!#!"+ *#$! '0 '"#!+! $" +!!%>
y
cku
tf
f
d
xp
max,
lim, 4.41=
+c,/tli%+or +3
250 "#5 500
#5 #-#>7 0-#@ 0-5#20 #-55 0-5@ 0-72
25 2-#" #-# 0-52
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L/+"* $%! '0 M'/!"+ '0 R!+$"! '0B$%$"! S!+'">
2max,max,
lim, 42.0136.0 bdfd
xd
xM ckuu
u
=
F'# F! 25J M,%/ J.14; 02
F'# F! 415 M,%/ J.13; 02
F'# F! 5JJ M,%/ J.133 02
( )max,umax,ucklim,u x42.0dbxf36.0M =
Sol*ero&le%
Menu S
UNDER (SINGLY) REINFORCED SECTION
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UNDER (SINGLY) REINFORCED SECTION
S!+'" "!# #!"0'#! 0 +!!% ('# $#!$'0 +!!%) 7#'! %! +-$" +-$+ #!?#! 0'#+-! $%$"! !+'" .!.
7+K 7+,%/ '# A+K A+,%/
d
&
A!t
xu%ax
0-00>5
0-002?0-@+;E!
0-"5+c,
0-"2xu
C 3 0->7+c, xu &
3 0-@+ A!t
Cro!!Section Strain ia$ra% Strain ia$ra% Stre!! ia$ra% Balanced Sec Gnder ein+ Sec
$%%$+"* 0#'/ +-! ?$#$+ !?$+'" !%'6>( )uucku x42.0dbxf36.0M = $"
=
2ck
u
y
ckst
bdf
M6.411bd
f
f
2
1A
Menu S
Sol*ero&le%
OVER REINFORCED SECTION
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OVER REINFORCED SECTION
S!+'" '!# #!"0'#! 0 +!!% ('# $#!$'0 +!!%) 7#'! /'#! +-$" +-$+ #!?#! 0'#
+-! $%$"! !+'" .!.7+ 7+,%/ '# A+ A+,%/
TO AVOID COMPRESSION FAILURE OF CONCRETE,&E NEVER PROVIDE AN OVER REINFORCED SECTION.
IMPORTANT>IN THE ABOVE CIRCUMSTANCES, THELOAD ON THE STRUCTURE HAS TO BE RESTRICTEDSUCH THAT IT DOES NOT GENERATE A MOMENTMORE THAN THE MOMENT OF RESISTANCE OF THEBALANCED SECTION. Menu SSol*e
ro&le%
DOUBLY REINFORCED SECTION
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I0 +-! !*" /'/!"+ $+"* '" +-! !+'" /'#! +-$" +-! /'/!"+ '0 #!+$"! '0 +-!
$%$"! !+'", +-! !+'" #!?#! +' !!*"! $ $ '%: #!"0'#!!+'".
M M,%/ M,%/ M1
T!"%! +!!% (A+1) 7#'! 0'# +-!$%$"! /'/!"+ M1.
A+'"$% +!"%! (A+2) $" '/7#!!+!!%(A) $#! 7#'! +' #!+ +-! /'/!"+ M2.!
/'/!"+ " !! '0 M,%/
DOUBLY REINFORCED SECTION
!c
http://var/www/apps/conversion/tmp/scratch_1/C:%5CCBTLimSt%5CRectBm.exehttp://var/www/apps/conversion/tmp/scratch_1/C:%5CCBTLimSt%5CRectBm.exe -
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d
&
A!t
xu
0-00>5
0-002?0-@+;E!
0-002
0-"5+c,
>xu;30-">xu"xu;30-5xu
0-"2xu
C 3 0->7+c, xu &
3 0-@+ A!t
Cro!!Section Strain ia$ra% Stre!! ia$ra%
3 d D 0-"2xu
A!c
STRESS=STRAIN DIAGRAMS
!c
d
A#!$ '0 '/7#!'"+!!%>
2st1stst AAA +=
sc
2stysc
f
Af87.0A =
OR
Menu S
Sol*ero&le%
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FLANGED BEAMS> T AND L BEAMS
I"+!#/!$+! !$/ ( T B!$/)
E*! B!$/ ( L B!$/)
<
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b"
&"
b'
d
Ast
c=0.0035
u
s
0.00
0.45"ck
T=0.*+"ckAst
C 0.43u
0.5+u
NA
Cross Sec Strain Diag Stress Diag
CASE 1> K D0 .!. N!+#$% A " +-! F%$"*!.
CASE 2> D0 K 3 .!. J.43 '# D03 '# D0 K J.2CASE 3> D0 3 .!. J.43 '# K D03 '# D0 J.2
I" $%% $'! $! K ,/$ .!. !+'" "!# #!"0'#!
CASE 4> ,/$ .!. '%: #!"0'#! !+'"
D0 3 .!. J.43 '# K D03 '# D0 J.2
.!0%$"*! " +-! 7$#$'% 7'#+'" '0 +-! +#!%'.
T' $%%$+! M,%/ 0'# $ !+'", +++! 6+-,/$ " +-! 0'#/%$ *!" !%'6.
$%%$+! : +#$% $" !##'# : '%"* +-!?$#$+ !?$+'" $" +++"* +-! $%! '0 :0 $
*!" !%'6. A%+!#"$+!%:, $" ! $%%$+! : +++"* M
6+- M $" !7#!"* :0 " +!#/ '0 $" '%"*+-! ?$#$+ !?$+'".
( ) ( ) ( )ff"fckuu"cku y5.0dybbf45.0x42.0dxbf36.0M +=
flan$%t&%'ft&ickn%ssM'difi%dyf =
ffu ##65.0x15.0 +=
D'%: #!"0'#! !+'"
I0 D!*" M'/!"+(M) M,%/, +-!!+'" +' ! !*"! $ $ D'%:R!"0'#! !+'".
T!"%! +!!% (A+1) 7#'! 0'# +-!
$%$"! /'/!"+ (M1 M,%/).
A+'"$% +!"%! (A+2) $" '/7#!!+!!% (A) $#! 7#'! +' #!+ +-!/'/!"+ M2 .! /'/!"+ " !! '0M,%/
M2 M M1 A+ A+1 A+2
<
( )
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Menu SSol*e
ro&le%
( )
y
f"fcku"ck1st
f87.0
ybbf45.0xbf36.0A
+=
A#!$ '0 +!!% 0'#B$%$"! S!+'"
A+'"$% A#!$ '0+!"%! +!!%
T'+$% +!"%! +!!%
A#!$ '0 C'/7#!'"+!!%
( )ddf87.0
MA
y
2u2st
=
2st1stst AAA +=
( )ddfscMA 2usc
= 6-!#! 0 $%%$+!$ " R!+$"*%$# B!$/
Exit
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