Sheet1
Design of Slab as per IS:456-2000:
Input Data:
1 2
2
Material :
Concrete Grade M 25
Reinforcement Steel Grade Fe415.
Dimensions:
3 4
Short Span : Lx: 3m 3 4
Long Span : Ly: 5.2 m
Effective Cover: 20 mm (Cover should comply clause 26.4
of IS:456)
Boundary Condition: 9 * For Two way slab,refer the sketch 5 6
on the right side.Dark line shows 5 6
the continuity.
* For one way continuous slab,
5 for Intermediate Panel,7 for end Panel,
* For one way discontinuous slab, 9.
7 8
* For cantilever slab, 10. 7 8
Load :
Floor Finish Load wf: 1.5 kN/m2
Live Load wL: 20 kN/m2
9
Load Factor for BM: 1.5
9
Load Factor for SF: 1.5
Calculations:
Aspect ratio=Ly/Lx= 1.73333333
Slab designed as: TWO WAY slab
Bending Moment Coefficients:
ax support = 0 For short span support moment.
ax span = 0.089 For short span span moment.
ay support = 0 For Long span support moment.
ay span = 0.056 For Long span span moment.
Depth assumed D = 150 mm OK
Selfweight wself =25xD/1000= 3.75 kN/m2 ( Density of concrete assumed 25 kN/m3)
Load intensity = w = wself+wf+wL= 25.25 kN/m2
Effective depth d= D - Eff. Cover= 130 mm
Factored Bending Moments=Factor x w x Coefficient x Lx2
Mu/bd2 pt req Ast req
% mm2/ m Explanation:
Mux support= 0 kN m 0 0 0 Mu/bd2=Mux106/(1000xd2)
Mux span= 30.337875 kN m 1.79514053 0.54683954 710.891 pt req is from charts of SP-16.
Muy support= 0 kN m 0 0 0 Ast= ptx1000xd/100
Muy span= 19.089 kN m 1.12952663 0.33103602 430.347
Minimum Ast req=0.12xD/1000= 180 mm2 per meter
Reinforcement Provided:
Short Span Support: 10 Dia at 150 c/c Ast= 523.33 ok
Short Span Span: 10 Dia at 100 c/c Ast= 785 ok
Long Span Support: 8 Dia at 150 c/c Ast= 334.93 ok
Long Span Span: 8 Dia at 100 c/c Ast= 502.4 ok
Check for Deflection:
Basic L/d = 20 (Clause 23.2.1 of IS 456-2000)
Modification factor= 1.47079098 ( Figure 4 of IS 456-2000)
d req as per deflection control=Lx/(Basic L/d x Modification factor )= 101.98593977 mm
d required < d provided so OK
Check for Shear:
Shear Force Vu= Factor x w x Lx/2= 56.8125 kN
Nominal Shear Stress=Vu/bd= 0.4370192 N/mm2
%reinforcement= 0.4025641 %
Beta= 2.01913043
tc= 0.73141547 N/mm2
k= 1.15
kxtc= 0.84112779 N/mm2
OK
Page 1
DALAL CONSULTANTS ENGINEERS LIMITED 09/07/2021
For Cantilever Slab,Parapet Wall Details:
Wall at the end of Wall Height: 0.9
Cantilever slab Wall Thk: 0.115
TWO WAY slab
Fck:- 25 Cover 20 REINFORCEMENT
Lx Lz WL WF Boundary treq tprov treq SHORT SPAN
SHORT LONG Live Finish Condition initial final SPAN SUPPORT
m m Kn/m Kn/m Required Provided Required Provided
3.00 5.2 20 1.5 9 121 150 122 10 110 10 100 10 436 10 150
LONG SPAN
1 2 3 SPAN SUPPORT
3
Required Provided Required Provided
4 5 6 8 117 8 100 8 279 8 150
6
7 5 9
8
9
Boundary Conditions: Two Way Slab: 1 to 9 as per code
One Way Slab: 5 for Intermediate panel
7 for End Panel
9 for Simply Supported
Cantilever Slab: 10
Page 2
Sheet3
TWO WAY SLAB:
Lx(Short Span) 3000 LL 20
Lz(Long Span) 5200 Finishing 1.5 1
Aspect ratio 1.7 dl 3.75 1.7
slab th(ini) 116.15385 w 25.25
slab th(pro) 150 wu 37.875
Boundary condition 9 Fck 25 3
3
Mu SUPP(short) 0 Ast req 180 Ast pro 523.33333
Mu SPAN (short) 30.337875 Ast req 710.8914 Ast pro 785
Mu SUPP(long) 0 Ast req 180 Ast pro 334.93333
5
Mu SPAN(long) 19.089 Ast req 430.34682 Ast pro 502.4 5
Thickness Req 121.98594
20
7
fs 217.97651 218 pt 0.4025641 7
l 1.470791
9
9
ax support = 0
ax span = 0.089
ay support = 0
ay span = 0.056
SLAB: REIN STEEL Fe415
CONCRETE GRADE fck= 25
B D d Mu Mu/Bd2 pt Ast Ast min
1000 150 130 0 0 0 0 180
1000 150 130 30.337875 1.7951405 0.5468395 710.8914 180
1000 150 130 0 0 0 0 180
1000 150 130 19.089 1.1295266 0.331036 430.34682 180
REQUIRD 8 TOR @ 281 C/C. MAXIMUM SPACING: 390
COMBINE 8 10 360 C/C
fs 0.2 0.3 0.4 0.5 0.6 0.7
120 2 2 2 2 2 1.9
145 2 2 2 1.9 1.8 1.68
190 2 1.85 1.7 1.55 1.4 1.35
240 1.7 1.5 1.35 1.25 1.15 1.1
290 1.4 1.25 1.15 1.075 1 0.95
lambda #N/A #N/A #N/A #N/A #N/A #N/A
#N/A
5 7 9 10
0.0833333 0.1 0.125 0.5
Page 3
Sheet3
1 2 3 4 5 6 7 8
0.053 0.057 0.067 0.075 0.06 0 0.084 0
0.041 0.044 0.051 0.056 0.045 0.068 0.064 0.076
0.032 0.037 0.037 0.047 0 0.045 0 0.057
0.024 0.028 0.028 0.035 0.035 0.035 0.043 0.043
Moments
Types of
Case no. considere
Panels
d Short Span Coefficients
(Values of ly/lx)
1 1.1 1.2 1.3 1.4
Interior
1
Negative moment at
Panels 0.032 0.037 0.043 0.047 0.051
conti. edge.
Positive moment at 0.024 0.028 0.032 0.036 0.039
Mid-span
One Short
Edge
2
Discontinu
ous.Negative moment at 0.037 0.043 0.048 0.051 0.055
conti. edge.
Positive moment at 0.028 0.032 0.036 0.039 0.041
Mid-span
One Long
Edge
3
Discontinu
ous.Negative moment at 0.037 0.044 0.052 0.057 0.063
conti. edge.
Positive moment at 0.028 0.033 0.039 0.044 0.047
Mid-span
Two
Adjacent
4 Edges
Discontinu
ous.Negative moment at
0.047 0.053 0.06 0.065 0.071
conti. edge.
Positive moment at
0.035 0.04 0.045 0.049 0.053
Mid-span
Two Short
Edges
5
Discontinu
ous.
Negative moment at0.045 0.049 0.052 0.056 0.059
conti. edge.
Positive mo 0.035 0.037 0.04 0.043 0.044
Mid-span
Two Long
Edges
6
Discontinu
ous.Negative moment at 0 0 0 0 0
conti. edge.
Positive moment at
0.035 0.043 0.051 0.057 0.063
Mid-span
Page 4
Sheet3
One Long
Edge
7
continuou
s. Negative moment at
0.057 0.064 0.071 0.076 0.08
conti. edge.
Positive moment at
0.043 0.048 0.053 0.057 0.06
Mid-span
One Short
Edge
8
continuou
s.
Negative moment at 0 0 0 0 0
conti. edge.
Positive moment at
0.043 0.051 0.059 0.065 0.071
Mid-span
Four
Edges
9
Discontinu
ous.Positive moment at
0.056 0.064 0.072 0.079 0.085
Mid-span
Page 5
Sheet3
2
2
4
4
6
6
8
8
0.8 1
1.8 1.6
1.55 1.4
1.3 1.2
1.05 1
0.9 0.85
#N/A #N/A
Page 6
Sheet3
9
0
0.089
0
0.056
Coefficient
s for all
n Coefficients values of
Values of ly/lx)
1.5 1.75 2 ly/lx
0.053 0.06 0.065 0.032
0.041 0.045 0.049 0.024
0.057 0.064 0.068 0.037
0.044 0.048 0.052 0.028
0.067 0.077 0.085 0.037
0.051 0.059 0.065 0.028
0.075 0.084 0.091 0.047
0.056 0.063 0.069 0.035
0.06 0.065 0.069 0
0.045 0.049 0.052 0.035
0 0 0 0.045
0.068 0.08 0.088 0.035
Page 7
Sheet3
0.084 0.091 0.097 0
0.064 0.069 0.073 0.043
0 0 0 0.057
0.076 0.087 0.096 0.043
0.089 0.1 0.107 0.056
Page 8
