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LARSEN & TOUBRO LIMITED ECC Division - GES
PART -4
DATE1861B-CS-05-00304
TITLE: HOSPITAL BUILDING - DESIGN OF PLAZA BEAMS & SLABSDESIGNED
SIDRA MEDICAL AND RESEARCH CENTER,QATAR DOCUMENT NO
ASN/STN CSR/MDS
PROJECT:21/05/09
CHECKED SHEET
(AT PLAZA LEVEL IN TOWER BLOCK OF HOSPITAL BUILDING)
ONE WAY SLAB DESIGN
7
LARSEN & TOUBRO LIMITEDECC Division - GES
DOCUMENT NO DATE
1861B-CS-05-00304CHECKED SHEET
2.0 DESIGN OF ONE WAY SLABS
In this section the design of slab for beam slab portion of part -4 is presented. This portion consist of oneway slabs supported by main beams and secondary beams. Slab thickness considered are 200 and 300mm. Analysis and design carried out as per BS 8110.
Unit weight of the concrete = kN/m3
Loads ConsideredSuperimposed Dead load = kN/m2
Live load = kN/m2
Soil unit weight (wet) = kN/m3
21/0509
5.55
20
25
PROJECT:
TITLE:
SIDRA MEDICAL & RESEARCH CENTER, DOHA
DESIGNED
STNHOSPITAL BUILDING - DESIGN OF PLAZA BEAMS & SLABS
CSR/MDS
8
9
LARSEN & TOUBRO LIMITED ECC Division - GES
DOCUMENT NO DATE
1861B-CS-05-00304CHECKED SHEET
Design of slab panels S5,S6,S7,S8 and S9
The design moments & shear forces are arrived based on clause 3.5.2.4 of BS 8110 Part 1 provisions by considering 1m wide strip of the one way slab.Loads are as follows.
Slab thickness = 200 mmSelf weight = 5 kN/m2
Super imposed dead load = 5.5 kN/m2
(a) Total Dead load (DL) = 10.5 kN/m2
(b) Live load (LL) = 5 kN/m2
Design factored load (Fu) =1.4DL+1.6LL = 22.7 kN/m2
Load for serviceability condition, (Fs) =DL+LL = 15.5 kN/m2
21/0509
CSR/MDS
PROJECT: SIDRA MEDICAL & RESEARCH CENTER, DOHA
TITLE: HOSPITAL BUILDING - DESIGN OF PLAZA BEAMS & SLABSDESIGNED
STN
Moment and Shear coefificients (Table 3.12, pg 37)
0 S5 S6 S7 -0.063 S8 S9
0.063
L5= L6= L7= L8= L9=
(a) Moment coefficients
S5 S6 S7 0.5 S8 S9
L5= L6= L7= L8= L9=
(b) Shear coefficients
-0.063
6m 6m 5.2m 5.2m
-0.063
0.063
0.5
5.2m6m
-0.086
5.2m6m
-0.063
0.5
0.086 0.063 0.063
5.1m
0.60.4 0.5
5.1m
10
LARSEN & TOUBRO LIMITED ECC Division - GES
DOCUMENT NO DATE
1861B-CS-05-00304CHECKED SHEET
21/0509
CSR/MDS
PROJECT: SIDRA MEDICAL & RESEARCH CENTER, DOHA
TITLE: HOSPITAL BUILDING - DESIGN OF PLAZA BEAMS & SLABSDESIGNED
STN
Bending moment and shear force diagram
(a) Strength case
Bending moment = (FuxL) x L x moment coefficient
-51.5
51 51.5(a) Bending Moment(kN-m)
Shear Force = (FuxL) x shear coefficient
46 82 68 68 59
-38.7
38.7
-38.7
38.7
-70.3
50.8
-51.5
69 68 68(b) Shear Force(kN)
(b) Seviceability case
Bending moment = (FsxL) x L x moment coefficient
-35.2
35 35.2(a) Bending Moment(kN-m)
Design for Flexure
Slab section is designed for maximum moment from the above calculation.Grade of Concrete, fcu = 40 N/mm2
Yield Strength of Steel, fy = 420 N/mm2
Cover to reinforcement = 30 mmSlab thickness, D = 200 mm
(a) Top Reinforcement (main bars)Maximum Hogging moment = 70.3 kN-mEffective depth, d = 162 mmBreadth, b = 1000 mm
-26.4
26.4 26.4
59 59
-48 -35.2 -26.4
34.7
11
LARSEN & TOUBRO LIMITED ECC Division - GES
DOCUMENT NO DATE
1861B-CS-05-00304CHECKED SHEET
21/0509
CSR/MDS
PROJECT: SIDRA MEDICAL & RESEARCH CENTER, DOHA
TITLE: HOSPITAL BUILDING - DESIGN OF PLAZA BEAMS & SLABSDESIGNED
STN
K = (Mu / fcub * d2 ) = 0.07 <�K'�(0.156)Z = Min[0.95d, d{0.5 + sqrt(0.25-K/0.9)}] = 148.9 mm
Area of Steel required, (Mu/(0.87fy*z) = 1292 mm2
Req�%Pt = 0.80 %Min. Ast required (0.13%) = 211 mm2
Ast provided = 1340 mm2
Provide mm dia bar at mm C/C as Top reinforcement (main bars)
(b) Bottom Reinforcement (main bars)Maximum Sagging moment = 51.5 kN-mEffective depth, d = 162 mm
Breadth, b = 1000 mmK = (Mu / fcub * d2 ) = 0.05 <�K'�(0.156)
Z = Min[0.95d, d{0.5 + sqrt(0.25-K/0.9)}] = 152.6 mmArea of Steel required, (Mu/(0.87fy*z) = 923 mm2
Req�%Pt = 0.57 %2
15016
Min. Ast required (0.13%) = 211 mm2
Ast provided = 1340 mm2
Provide mm dia bar at mm C/C as Bottom reinforcement (main bars)(c) Secondary reinforcement
Minimum reinforcement shall be provided both top and bottom secondary reinforcemetMin Percentage of Ast = 0.13 % Ast min = 211 mm2
Ast provided = 524 mm2
Provide mm dia bar at mm C/C on as secondary bars both at top and bottom
Check for Shear
Allowable�shear�stress�in�concrete (using Table 3.8, pg 30 BS8110 part1)
vc = 0.79[100As/(bvd)]1/3 (400/d)1/4/�m
(multiplication factor for concrete grade > 25 = (fcu/25)1/3 ) vc = N/mm2
(where, As = , bv = 1000 d = , �m = 1.25)Maximum shear, v = Vu/bd
(Vu = 82 kN, b=1000, d= ) v = N/mm2
< ��vc Hence Safe
Check for deflection (Cl 3.4.6.3 of BS8110 part 1)
Basic span/effective depth ratio from table 3.9 = 20(conservatively taken for simply supported condition)
Modification factors(a) For Tension reinforcement (Using Table 3.10 of the code)
10 150
0.87
16 150
1340
162 0.50
162
12
LARSEN & TOUBRO LIMITED ECC Division - GES
DOCUMENT NO DATE
1861B-CS-05-00304CHECKED SHEET
21/0509
CSR/MDS
PROJECT: SIDRA MEDICAL & RESEARCH CENTER, DOHA
TITLE: HOSPITAL BUILDING - DESIGN OF PLAZA BEAMS & SLABSDESIGNED
STN
Design service stress, fs = 2fyAs req/(3As prov �b)
= 161 N/mm2
where, As req = mm2
As prov = mm2
�b = for 20%redistribution
Mu/bd2 = 1.96
Modification factor = 0.55 + (477-fs) / [120(0.9+Mu/bd2] < 2.0= 1.47 < 2.0
(b) For Compression reinforcement (Using Table 3.11 of the code)
As`prov = mm2 100As`prov/bd = Modification factor = 1 + (100As`prov/bd) / (3+ 100As`prov/bd) < 1.5
= < 1.5Allowable span/effective depth ratio = 20 x 1.47 x 1.22
1340 0.83
1.22
13401.2
923
= 35.8Actual ratio = 5.1 x 1000 / 162 = 31.5 Hence safe against deflection
Check for crack width
Crack width is calculated and and attached seperately
Note: Same design shall be followed for similar one way panals such as S18, S19, S20, S21, S22, S23S13,S14,S15,S16,S17,S1,S2
13
LARSEN & TOUBRO LIMITED ECC Division - GES
DOCUMENT NO DATE1861B-CS-05-00304 21.05.09
CHECKED SHEET
Design of slab panels S4 (Refer section 9a-9a)
The design moments & shear force are arrived by taking the slab as a simply supported slab considering 1m wide strip of the one way slab.Design loads are as follows.
Slab thickness = 300 mmSelf weight = 7.5 kN/m2
Super imposed dead load = 0 kN/m2
1 m Soil filling (20x1) = 20 kN/m2
(a) Total Dead load (DL) = 27.5 kN/m2
(b) Live load (LL) = 5 kN/m2
Design factored load (Fu) =1.4DL+1.6LL = 46.5 kN/m2
Load for serviceability condition, (Fs) =DL+LL = 32.5 kN/m2
Clear span, L = 4.3 mEff ti S 4 6
DESIGNED
STN
PROJECT: SIDRA MEDICAL & RESEARCH CENTER, DOHA
TITLE: HOSPITAL BUILDING - DESIGN OF PLAZA BEAMS & SLABSCSR/MDS
Effective Span = 4.6 mMaximum Span moment, Mu = FuL
2/8 = 107 kN-mMaximum Shear force, Vu = FuL/2 = 100 kN
Moment under serviceability condition, Mu = FsL2/8 = 75 kN-m
Design for Flexure
Slab section is designed for maximum moment.Grade of Concrete, fcu = 40 N/mm2
Yield Strength of Steel, fy = 420 N/mm2
Cover to reinforcement = 30 mmSlab thickness, D = 300 mm
(a) Bottom Reinforcement (main bars)Maximum Sagging moment = 107 kN-mEffective depth, d = 262 mm
Breadth, b = 1000 mmK = (Mu / fcub * d2 ) = 0.04 <�K'�(0.156)
Z = Min[0.95d, d{0.5 + sqrt(0.25-K/0.9)}] = 249 mmArea of Steel required, (Mu/(0.87fy*z) = 1182 mm2
Req�%Pt = 0.45 %Min. Ast required (0.13%) = 341 mm2
Ast provided = 1340 mm2
Provide mm dia bar at mm C/C as Bottom reinforcement (main bars)(b) Top reinforcement
Provide 50% of bottom steel = 670 mm2
16 150
14
LARSEN & TOUBRO LIMITED ECC Division - GES
DOCUMENT NO DATE1861B-CS-05-00304 21.05.09
CHECKED SHEETDESIGNED
STN
PROJECT: SIDRA MEDICAL & RESEARCH CENTER, DOHA
TITLE: HOSPITAL BUILDING - DESIGN OF PLAZA BEAMS & SLABSCSR/MDS
Min Percentage of Ast = 0.13 % Ast min = 341 mm2
Ast provided = 1340 mm2
Provide mm dia bar at mm C/C on as top reinforcement (main bars)(c) Secondary reinforcement
Minimum reinforcement shall be provided both top and bottom secondary reinforcemetMin Percentage of Ast = 0.13 % Ast min = 341 mm2
Ast provided = 524 mm2
Provide mm dia bar at mm C/C on as secondary bars both at top and bottom
Check for Shear
Allowable�shear�stress�in�concrete (using Table 3.8, pg 30 BS8110 part1)
vc = 0.79[100As/(bvd)]1/3 (400/d)1/4/�m
(multiplication factor for concrete grade > 25 = (fcu/25)1/3 ) vc = N/mm2
16 150
0.66
10 150
(where, As = , bv = 1000 d = , �m = 1.25)Maximum shear, v = Vu/bd
(Vu = kN, b=1000, d= ) v = N/mm2
< ��vc Hence Safe
Check for deflection (Cl 3.4.6.3 of BS8110 part 1)
Basic span/effective depth ratio from table 3.9 = 20(for simply supported condition)
Modification factors(a) For Tension reinforcement (Using Table 3.10 of the code)
Design service stress, fs = 2fyAs req/(3As prov �b)
= 247 N/mm2
where, As req = mm2
As prov = mm2
�b =Mu/bd2 = 1.57
Modification factor = 0.55 + (477-fs) / [120(0.9+Mu/bd2] < 2.0= 1.33 < 2.0
(b) For Compression reinforcement (Using Table 3.11 of the code)As`prov = mm2 100As`prov/bd =
Modification factor = 1 + (100As`prov/bd) / (3+ 100As`prov/bd) < 1.5
= < 1.5Allowable span/effective depth ratio = 20 x 1.33 x 1.15
= 30.4
100
1340 262
262 0.38
11821340
1
1340 0.51
1.15
15
LARSEN & TOUBRO LIMITED ECC Division - GES
DOCUMENT NO DATE1861B-CS-05-00304 21.05.09
CHECKED SHEETDESIGNED
STN
PROJECT: SIDRA MEDICAL & RESEARCH CENTER, DOHA
TITLE: HOSPITAL BUILDING - DESIGN OF PLAZA BEAMS & SLABSCSR/MDS
Actual ratio = 4.6 x 1000 / 262 = 17.6 Hence safe against deflection
Check for crack width
Crack width is calculated and and attached seperately.
Note: Same design shall be followed for similar one way panals such as S11
16
LARSEN & TOUBRO LIMITED ECC Division - GES
DOCUMENT NO DATE
1861B-CS-05-00304 21.05.09CHECKED SHEET
Design of slab panels S3 (Refer section 20a-20a)
The design moments & shear force are arrived by taking the slab as a simply supported slab considering 1m wide strip of the one way slab.Design loads are as follows.
Slab thickness = 300 mmSelf weight = 7.5 kN/m2
Super imposed dead load = 5.5 kN/m2
(a) Total Dead load (DL) = 13 kN/m2
(b) Live load (LL) = 5 kN/m2
Design factored load (Fu) =1.4DL+1.6LL = 26.2 kN/m2
Load for serviceability condition, (Fs) =DL+LL = 18 kN/m2
Clear span, L = 5.5 mEff ti S 5 8
PROJECT: SIDRA MEDICAL & RESEARCH CENTER, DOHA
TITLE: HOSPITAL BUILDING - DESIGN OF PLAZA BEAMS & SLABSDESIGNED
CSR/MDSSTN
Effective Span = 5.8 mMaximum Span moment, Mu = FuL
2/8 = 99 kN-mMaximum Shear force, Vu = FuL/2 = 72 kN
Moment under serviceability condition, Mu = FsL2/8 = 68 kN-m
Design for Flexure
Slab section is designed for maximum moment.Grade of Concrete, fcu = 40 N/mm2
Yield Strength of Steel, fy = 420 N/mm2
Cover to reinforcement = 30 mmSlab thickness, D = 300 mm
(a) Bottom Reinforcement (main bars)Maximum Sagging moment = 99 kN-mEffective depth, d = 262 mm
Breadth, b = 1000 mmK = (Mu / fcub * d2 ) = 0.04 <�K'�(0.156)
Z = Min[0.95d, d{0.5 + sqrt(0.25-K/0.9)}] = 249 mmArea of Steel required, (Mu/(0.87fy*z) = 1089 mm2
Req�%Pt = 0.42 %Min. Ast required (0.13%) = 341 mm2
Ast provided = 1340 mm2
Provide mm dia bar at mm C/C as Bottom reinforcement (main bars)(b) Top reinforcement
Provide 50% of bottom steel = 670 mm2
16 150
17
LARSEN & TOUBRO LIMITED ECC Division - GES
DOCUMENT NO DATE
1861B-CS-05-00304 21.05.09CHECKED SHEET
PROJECT: SIDRA MEDICAL & RESEARCH CENTER, DOHA
TITLE: HOSPITAL BUILDING - DESIGN OF PLAZA BEAMS & SLABSDESIGNED
CSR/MDSSTN
Min Percentage of Ast = 0.13 % Ast min = 341 mm2
Ast provided = 1340 mm2
Provide mm dia bar at mm C/C on as top reinforcement (main bars)(c) Secondary reinforcement
Considering the irregular shape and support conditions for this slab, provide higher reinforcementMin Percentage of Ast = 0.13 % Ast min = 341 mm2
Ast provided = 1340 mm2
Provide mm dia bar at mm C/C on as secondary bars both at top and bottom
Check for Shear
Allowable�shear�stress�in�concrete (using Table 3.8, pg 30 BS8110 part1)
vc = 0.79[100As/(bvd)]1/3 (400/d)1/4/�m
(multiplication factor for concrete grade > 25 = (fcu/25)1/3 ) vc = N/mm20.66
16 150
16 150
(where, As = , bv = 1000 d = , �m = 1.25)Maximum shear, v = Vu/bd
(Vu = 72 kN, b=1000, d= ) v = N/mm2
< ��vc Hence Safe
Check for deflection (Cl 3.4.6.3 of BS8110 part 1)
Basic span/effective depth ratio from table 3.9 = 20(for simply supported condition)
Modification factors(a) For Tension reinforcement (Using Table 3.10 of the code)
Design service stress, fs = 2fyAs req/(3As prov �b)
= 228 N/mm2
where, As req = mm2
As prov = mm2
�b =Mu/bd2 = 1.44
Modification factor = 0.55 + (477-fs) / [120(0.9+Mu/bd2] < 2.0= 1.44 < 2.0
(b) For Compression reinforcement (Using Table 3.11 of the code)As`prov = mm2 100As`prov/bd =
Modification factor = 1 + (100As`prov/bd) / (3+ 100As`prov/bd) < 1.5
= < 1.5Allowable span/effective depth ratio = 20 x 1.44 x 1.15
= 32.9
13401
1340 0.51
1.15
1340 262
262 0.28
1089
18
LARSEN & TOUBRO LIMITED ECC Division - GES
DOCUMENT NO DATE
1861B-CS-05-00304 21.05.09CHECKED SHEET
PROJECT: SIDRA MEDICAL & RESEARCH CENTER, DOHA
TITLE: HOSPITAL BUILDING - DESIGN OF PLAZA BEAMS & SLABSDESIGNED
CSR/MDSSTN
Actual ratio = 5.8 x 1000 / 262 = 22.1 Hence safe against deflection
Check for crack width
Crack width is calculated and and attached seperately.
19
LARSEN & TOUBRO LIMITED ECC Division - GES
Calculation for crack width (For slab panal - S5)
Moment due to service load = kNmWidth of slab (b) =Overall depth of slab (h) =Area of steel provided (As) = mm2
Clear cover to tension steel provided (c) =Diameter of bar provided on the tension face (�) =Effective depth of slab (d) = 200-30-16/2 =Spacing of steel (s) = mm c/cAs per BS8110-2:1985 Design Surface Crack Width
Wcr = 3acr�m/(1+2(acr-Cmin)/(h-x))Where
x = depth of neutral axis = mm61 6
150
30 mm16 mm162 mm
48.01000 mm200 mm1340
TITLE: Hospital Building - Crack width calculation DESIGNED CHECKED SHEET
STN CSR/MDS
PROJECT: SIDRA MEDICAL AND RESEARCH CENTER,QATAR DOCUMENT NO DATE1861B-CS-05-00304 21/0509
x = depth of neutral axis. = mmfs = the tensile stress in the reinforcement.
= M(d-x)/I = N/mm2
�1 = Strain at the level considered, calculated ignoringthe stiffening of the concrete in the tension zone.�1 = (h-x)fs/Es(d-x) =
�m = average steel strain at the level considered,�1 - b(h-x)(a-x)/(3EsAs(d-x)) =
a = distance from the compression face to the point atwhich crack width is being calculated, and =
Actual crack width:
acr = distance from the point considered to the surfaceof the nearest longitudinal bar = mm
Wcr = Crack width = mm
Allowable crack width = mm
HENCE SAFE
76.1
0.206
0.300
61.6
253
0.00174
0.00151
200 mm
20
LARSEN & TOUBRO LIMITED ECC Division - GES
Calculation for crack width (For slab panal - S4)
Moment due to service load = kNmWidth of slab (b) =Overall depth of slab (h) =Area of steel provided (As) = mm2
Clear cover to tension steel provided (c) =Diameter of bar provided on the tension face (�) =Effective depth of slab (d) = 300-30-16/2 =Spacing of steel (s) = mm c/cAs per BS8110-2:1985 Design Surface Crack Width
Wcr = 3acr�m/(1+2(acr-Cmin)/(h-x))Where
x = depth of neutral axis = mm82 4
150
30 mm16 mm262 mm
75.11000 mm300 mm1340
TITLE: Hospital Building - Crack width calculation DESIGNED CHECKED SHEET
STN CSR/MDS
PROJECT: SIDRA MEDICAL AND RESEARCH CENTER,QATAR DOCUMENT NO DATE1861B-CS-05-00304 21/5/09
x = depth of neutral axis. = mmfs = the tensile stress in the reinforcement.
= M(d-x)/I = N/mm2
�1 = Strain at the level considered, calculated ignoringthe stiffening of the concrete in the tension zone.�1 = (h-x)fs/Es(d-x) =
�m = average steel strain at the level considered,�1 - b(h-x)(a-x)/(3EsAs(d-x)) =
a = distance from the compression face to the point atwhich crack width is being calculated, and =
Actual crack width:
acr = distance from the point considered to the surfaceof the nearest longitudinal bar = mm
Wcr = Crack width = mm
Allowable crack width = mm
HENCE SAFE
76.1
0.179
0.300
82.4
239
0.00145
0.00112
300 mm
21
LARSEN & TOUBRO LIMITED ECC Division - GES
Calculation for crack width (For slab panal - S3)
Moment due to service load = kNmWidth of slab (b) =Overall depth of slab (h) =Area of steel provided (As) = mm2
Clear cover to tension steel provided (c) =Diameter of bar provided on the tension face (�) =Effective depth of slab (d) = 300-30-16/2 =Spacing of steel (s) = mm c/cAs per BS8110-2:1985 Design Surface Crack Width
Wcr = 3acr�m/(1+2(acr-Cmin)/(h-x))Where
x = depth of neutral axis = mm82 4
150
30 mm16 mm262 mm
68.11000 mm300 mm1340
TITLE: Hospital Building - Crack width calculation DESIGNED CHECKED SHEET
STN CSR/MDS
PROJECT: SIDRA MEDICAL & RESEARCH CENTER, DOHA DOCUMENT NO DATE1861B-CS-05-00304 21/5/09
x = depth of neutral axis. = mmfs = the tensile stress in the reinforcement.
= M(d-x)/I = N/mm2
�1 = Strain at the level considered, calculated ignoringthe stiffening of the concrete in the tension zone.�1 = (h-x)fs/Es(d-x) =
�m = average steel strain at the level considered,�1 - b(h-x)(a-x)/(3EsAs(d-x)) =
a = distance from the compression face to the point atwhich crack width is being calculated, and =
Actual crack width:
acr = distance from the point considered to the surfaceof the nearest longitudinal bar = mm
Wcr = Crack width = mm
Allowable crack width = mm
HENCE SAFE
76.1
0.158
0.300
82.4
216
0.00131
0.00098
300 mm
22
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