55168959-shear-wall
DESCRIPTION
shearwallTRANSCRIPT
SHEAR WALL DESIGN
Grade of concrete M 20
Characteristic strength of steel Fy 415
Thickness of web tw 115 mm
Overall length of wall Lw = 1800 mm
Dimension of wall at one end d1 = 230 mm
Dimension of wall at another end d2 = 115 mmEffective length of wall Le = Lw-d1/2-d2/2 Le = 1627.5 mmAxial load (DL+LL) P = 2850 kN
(EQ) P' = 0Shear force (DL+LL) V = 275 kN
(EQ) V' = 0Bending Moment (DL+LL) M = 250 kNm
(EQ) M' = 0
N/mm2
N/mm2
SHEAR DESIGN
Thickness of web tw = 115 mmFactor 1.2
Factored Shear Vu = V * factor Vu = 330 kN
Overall length of wall Lw Lw = 1800 mm
Effective length of wall Le = Lw-d1/2-d2/2 Le = 1627.5 mm
dw = 0.8*Lw dw = 1440 mm
is replaced by Tc
Tc from IS : 456 Tc = 0.36
Tv = Vu Vu = 1.99tw * dw
Condition is Tv > Tc
Tv < Tc
Min % of steel to be provided is 0.25% Ag= 414Diameter of bar used db = 8 mm
Spacing = 122 mm
Reinforcement shall be provided in two curtains
If Tw > 200mm Ag'=Ag/2 Ag' = 207Diameter of bar used db = 8 mm
Spacing = 243 mm
Provide 8 # @ 122 mm c/c
Tv > Tc
Vus = Vu - Tc * tw * dw Vus = 271 kN
Vus = 0.87 * fy * Ah * dw Ah/Sv = 0.52 % Sv
Diameter of bar used db = 8spacing = 90 Trial and errorAh/Sv = 0.56 %
Provide 8 # @ 90 mm c/c
tc
N/mm2
mm2
If thickness of wall is > 200mm or factored sheat stress in thewall exceeds 0.25(fck)1/2,
mm2
11.5 mm
1] lw/5 3602] 3*tw 3453] 450 450
Trial and error
Diameter should be less than tw/10
Spacing not be greater than lesser of
FLEXURAL STRENGTH OF WEB
Axial Compression will increase the moment capacity of wall
Hence the factored axial force Pu= P*0.8+P' *factorfactor 1.2Pu = 3420 kN
Moment of resistance provided by distributed vertical reinforcement across wall section
Considering 0.25% vertical reinforcement in web p = 0.008
0.87*fy*p 0.144 fck
Pu 0.83fck*tw*lw
xu = f+l xu = 1.50 lw lw
xu' = 0.0035 Es = xu' = 0.66 lw 0.0035+0.87*fy/Es lw
0.87*fy 0.516Es*0.0035
Condition is xu'/lw < xu/lw <1
xu/lw < xu'/lw
Muv =
lw lw 3
Muv = 2115 kNm
xu'/lw < xu/lw < 1
0.327
0.129
-0.1088
[ f/b -l ] -0.546
0.140
X = 1.45-0.7497
Muv :-
f = f =
l = l =
2f+0.36
2x105
b = b =
f [ 1+l) (1-0.416xu ) - xu 2 (0.168+b2)
fck*tw*lw2 f
a1 = [0.36+f ( 1-b/2 - 1/2b)] a1 =
a2 = [ 0.15+ f ( 1-b-b2/2-1/3b)] a2 =
a3 = [ f / 6b *(1/(xu/lw) - 3) ] a3 =
a4 = a4 =
a5 = [ f/2b ] a5 =
Substituting xu/lw as X in following equation to derive new value of xu/lw
a1 (X)2 + a4 (X) - a5 =0
Muv = Muv = 748 kNm
-0.10026
[ a1 (X) -a2 (X2) - a3 - l/2 ] * fck * tw * lw2
-747.16
BONDING ELEMENT
Factored Moment Mu Factor 1.2Mu = 300 kNm
Cv - c/c distance b/w bonding element Cv = 1627.5 mmAssume dimension of element b = 230 mm
d = 450 mm
The moment to be resisted by bonding element is Mu-Muv Mu-Muv -448 kNm
C = Mu-Muv C = 275.2688 kNm Cv
Max factored compression on boundry elementCu = Cu = 1004 kN
Max factored tension on boundry elementTu = Tu = 454 kN
Assuming short column action, the axial load capacity of the boundry elementwith minimum reinforcement of 0.8% is P*% of reinforcement > 0.8% but < 6% preferably <4%
p = 1.8P* = [ 0.4 fck +p/100 (0.67 fy - 0.4fck) ] Ag p* = 1332 kN
Ast = 1863Diameter of bar used db = 16
No = 10
Provide 10 No 16 #
Special confining reinforcement shall be provided as in the case of columnIf entire wall is provided by special confinement, boundry element is not required to be provided
C+(0.213*factor*( P+P' )
(0.213*factor*( P+P' ) -C
mm2
If entire wall is provided by special confinement, boundry element is not required to be provided