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Page 1: Design Beam

1

BS8110 REF. CALCULATION OUTPUT

I/ Design BeamGB9A effective span= 7.7 m

1 -Loading Slab Panel 7.7 x 2.3 m and 0.1 mTHK (Slab on one side of the beam)

Dead Load

Slab 24 kN/m³ x 2.08 m³ / 7.7 = 6.48 kN/m

Beam 25 kN/m³ x 1.05 m³ / 7.7 = 3.4 kN/m

Other 1 kN/m² x 2.25 m = 2.25 kN/m

Wall 10cm 1.2 kN/m² x 2.25 m = 2.7 kN/m

Wall 20cm 0 kN/m² x 0 m = 0 kN/m

Floor Finis 1.5 kN/m² x 2.25 m = 3.38 kN/m

Total Dead Lo ### kN/m (Trapezoidal Dead load per m lenght

Live Load or Imposed load on one side of the beam)

Floor LL 4 kN/m² x 2.25 m³ / m = 9 kN/m

Total live Load 9 kN/m (Trapezoidal Live load per m lenght

Design Load on one side of the beam)

Design Load1.6 x ### )+( 1.4 x 9.00 ) = 42 kN/m (Trapezoidal load= 41.73 kN/m)

Convert Trapezoidal load to uniformly distributed load

Uniformly distributed ### x 0.73 ) = 30 kN/m

Load on the other side of th 30 - ( ### x 30 / 100 )= 21 kN/m (Reduce 30% for the load on

the other side)

Total Load on both side of t 30 + ### = ### kN/m

2 -Bending Moment

Max moment at suppo = - ql²/12 = ### kN/m

Max moment at mid s = ql²/24 = ### kN/m

Msup

Mmid

Page 2: Design Beam

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3 -Beam Section

h=L

toL

=7700

to7700

» h= 550 mm » h= 400 mm10 15 10 15

b=(0.4 to 0.5)h= (0.4 to 0.5400 » b= 248 mm » b= 200 mm

Cover: C= 25 mm 6 mm ; 20 mm

d= = 400 - 25 - 3 - 10 = 362 mm » d'= 35 mm

ii -Define Steel Area

Assume fcu= 30 N/mm² ; fy v= 250 N/mm² fy = 390 N/mm²

a -Define Steel Area at Support Mmax= 255.89 kNm

k=M

=256 x

0.325 > 0.156200 x 131044 x 30

z =d.[0.5+(0.25-(k'/0.9))^(1/ 2)]=362.[0.5+(0.25-(0.132/ 0.9)^(1/ 2))]= 297 mm

that z not exceed 0.95d= 344 mm so z = 344 mm

» [(k'. fcu.b.d^2)/(0.87.fy.z)]+ = [(0.13x30x200x362^2)x10^6) / (0.87x390x343.

3087.5 » Assume 11 T 20 » ###

» P=100(As,req / bd) 4.32 > 0.13 < 4 » OK

b -Define Steel Area at Mid span Mmax= 160 kNm

k=M

=160 x

0.203 > 0.156200 x 131044 x 30

z =d.[0.5+(0.25-(k'/0.9))^(1/ 2)]=.[0.5+(0.25-(0.132/ 0.9)^(1/ 2))]= 297 mm

that z not exceed 0.95d= 344 mm so z = 297 mm

» [(k'. fcu.b.d^2)/(0.87.fy.z)]+ = [(0.13x30x200x362^2) x10^6)/ (0.87x3

2285.9 » Assume 9 T 20 » ###

;Assume Steel Bar ØDR= DT=

h - C - DR/2 - DT/2

106 (Doubly Reinforced

Section)bd2fcu

As =

As = mm2 As= mm2

106 (Doubly Reinforced

Section)bd2fcu

As =

As = mm2 As= mm2

Page 3: Design Beam

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» P=100(As,req / bd) 3.53 > 0.13 < 4 » OK

c -Check Deflection

=160 x

= 6.10200 x 1E+05

fs =5

fy =5

x 390 x###

= 197 (Service Stress)8 8 ###

modification factor = 0.55 +477 - fs

= 1120

Bassic span/depth = 26 ( table3.9 in Code BS8110 Part 1 1985)

Allowable span/depth= 26 x 1 = 25

Actual span/depth = lx / dx = ### / 362 = 21

» »Allowable span/depth= 25 >Actual span/depth= 21 » OK

c -Link

Max Shear at Support

= 168 kN

= / bd = 168x(10^3) / 200x362= 2.32 N/mm²

= (0.79/1.25) [(100As/bd)^(1/3)] [(400/d)^(1/4)] [(fcu/25)^(1/3)]

= 0.63 x [((100x2826)/(200x362))^(1/3)]x(400/362)^(1/4)x(30/25)^(1/3)

= 1.08

= 2.32 N/mm² > +0.4=1.48 N/mm² (Case 3 in table3.7 in Code BS8110)

Assume 6 mm » Area of link Asv= 55

» Link Spacin = 48 mm » 80 mm

Hence R6@80

Shear at L/4 from the support

= 150 kN

Mmax 106

bd2

As,req

As,pro

(0.9+(M / bd2))

Vmax

Vstress Vmax

Vcapacity

Vstress Vcapacity

Asv≥(bv Sv(vs-vc))/0.87fy mm2

Sv≤(Asv x 0.87fy)/(bv(vs-vc))

Vl/4

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= 2.07 N/mm²

= 1.08 N/mm² Assume 6 mm » Area of link Asv= 55

» Link Spacin = 60 mm » 180 mm

Hence R6@180

Vstress

Vcap. mm2

Sv≤(Asv x 0.87fy)/(bv(vs-vc))

Page 5: Design Beam

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RE-Design Section of Ground GB9A

BS8110 REF. CALCULATION OUTPUT

I/ Design BeamGB9A effective span= 5 m

1 -Loading Slab Panel 5 x 2.5 m and 5 x 2.5 m and 0.1 mTHK

Dead Load

Left Side of the beam Right Side of the beam

Slab 24 kN/m³ x 0.12 x 2.5 = 7.2 kN/m 24 kN/m³ x 0.12 x 2.5 = 7.2 kN/m

Beam 24 kN/m³ x 0.35 x 0.2 = 1.68 kN/m

Other 0 kN/m²x 2.5 = 0 kN/m 0 kN/m²x 2.5 = 0 kN/m

Wall 10cm 1.2 kN/m²x 3.3 = 3.96 kN/m 1.2 kN/m²x 3.3 = 3.96 kN/m

Wall 20cm 0 kN/m²x 0 = 0 kN/m 0 kN/m²x 0 = 0 kN/m

Floor Finish 1.5 kN/m²x 3.3 = 4.95 kN/m 1.5 kN/m²x 3.3 = 4.95 kN/m

Total Dead Load ### kN/m ### kN/m

Live Load or Imposed load

Floor LL 1.5 kN/m² x 2.5 m = 3.75 kN/m 1.5 kN/m² x 2.5 m = 3.75 kN/m

Total live Load 3.8 kN/m 3.8 kN/m

Triangle or Trapezoidal Design Load

(1.4 x 17.79) + (1.6 x 3.75) = ### kN/m (1.4 x 16.11) + (1.6 x 3. = ### kN/m

Convert Trapezoidal load to uniformly distributed load for bending moment

Uniformly distributed 30.9 x 0.7 = 21 kN/m 28.6 x 0.7 = 19 kN/m

Total uniformly distributed load

20.6 + 19 = 39 kN/m

Page 6: Design Beam

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BS8110 REF. CALCULATION OUTPUT

2 -Bending Moment

Max moment at suppo = - ql²/12 = -82.14 kN/m

Max moment at mid s = ql²/24 = 41.07 kN/m

3 -Beam Section

h=L

toL

=5000

to5000

» h= 357 mm » h= 350 mm10 15 10 15

b=(0.4 to 0.5)h= (0.4 to 0.5350 » b= 161 mm » b= 200 mm

Cover: C= 25 mm 6 mm ; 16 mm

d= = 350 - 25 - 3 - 8 = 314 mm d'= 33 mm

4 -Define Steel Area

Assume fcu= 30 N/mm² ; fy v= 250 N/mm² fy = 390 N/mm²

a -Define Steel Area at Support Mmax= 82.14 kNm

k=M

=82 x

0.139 < 0.156200 x 98596 x 30

z = d.[0.5+(0.25-(k/0.9))^(1/ 2)]=314.[0.5+(0.25-(0.139/ 0.9)^(1/ 2))]= 254 mm

that z not exceed 0.95d= 298 mm so z = 298 mm

x = ( 314 - 298 )/ 0.45 = 34.89

» Compression Steel Area

» No Steel Require

» Tension Steel Area

» M /0.87 fy.z = [(82x10^6) / (0.87x390x298.3)]

811.59 » Assume 5 T 16 » ###

» P=100(As,req / bd) 1.44 > 0.13 < 4 » OK

Msup

Mmid

;Assume Steel Bar ØDR= DT=

h - C - DR/2 - DT/2

106 (Singly Rienforced

Section)bd2fcu

As =

As = mm2 As= mm2

Page 7: Design Beam

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BS8110 REF. CALCULATION OUTPUT

b -Define Steel Area at Mid sp Mmax= 41.07 kNm

k=M

=41 x

0.069 < 0.156200 x 98596 x 30

z = d.[0.5+(0.25-(k/0.9))^(1/ 2)]=.[0.5+(0.25-(0.069/ 0.9)^(1/ 2))]= 288 mm

that z not exceed 0.95d= 298 mm so z = 298 mm

x = ( 0 - 298 )/ 0.45 = -663

» Compression Steel Area

» No Steel Require

» Tension Steel Area

» M /0.87 fy.z = [(41x10^6) / (0.87x390x298.3)]

405.8 » Assume 3 T 16 603

» P=100(As,req / bd) 0.96 > 0.13 < 4 » OK

c -Check Deflection

=41.1 x

= 2.08200 x 98596

fs =5

fy =5

x 390 x406

= 164 (Service Stress)8 8 603

modification factor = 0.55 +477 - fs

= 1.94120

Bassic span/depth = 26 ( table3.9 in Code BS8110 Part 1 1985)

Allowable span/depth= 26 x 1.94 = 50

Actual span/depth = lx / dx = ### / 314 = 16

» »Allowable span/depth= 50 >Actual span/depth= 16 » OK

106 (Singly Rienforced

Section)bd2fcu

As =

As = mm2 As= mm2

Mmax 106

bd2

As,req

As,pro

(0.9+(M / bd2))

Page 8: Design Beam

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BS8110 REF. CALCULATION OUTPUT

d -Link

Convert Trapezoidal load to uniformly distributed load for bending moment

Left Side of the beam Right Side of the beam

Uniformly distributed 30.9 x 0.5 = 15 kN/m 28.6 x 0.5 = 14 kN/m

Total uniformly distributed load

15.5 + 14 = 30 kN/m Total load per m lenght for

bending moment 29.7 kN/m

Max Shear at Support

= ql/2 = 74 kN

= / bd = 1.18 N/mm²

= (0.79/1.25) [(100As/bd)^(1/3)] [(400/d)^(1/4)] [(fcu/25)^(1/3)]

= 0.83 N/mm²

= 1.18 N/mm² > +0.4=1.23 N/mm²(Case 3 in table3.7 in Code BS8110)

Assume 6 mm » Area of link Asv= 55

» Link Spacin = 170 mm » 120 mm

Hence R6@120

Shear at L/4 from the support

= q(l-0.25l)/2 = 55.7 kN

= 0.89 N/mm²

= 0.83 N/mm² Assume 6 mm » Area of link Asv= 55

» Link Spacin = ### mm » 150 mm

Hence R6@150

Vmax

Vstress Vmax

Vcapacity

Vstress Vcapacity

mm2

Sv≤(Asv x 0.87fy)/(bv(vs-vc))

Vl/4

Vstress

Vcap. mm2

Sv≤(Asv x 0.87fy)/(bv(vs-vc))

Page 9: Design Beam

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Check Existing Section of Ground Beam GB7 (Along Grid 4 from Grid E-G)

BS8110 REF. CALCULATION OUTPUT

I/ Check ExistiGB7 effective span= 6.6 m

A Loading Slab Panel 6.6 x 3.3 m and 6.6 x 1.1 m and 0.1 mTHK

Dead Load

Left Side of the beam Right Side of the beam

Slab 24 kN/m³ x 0.1 x 3.3 = 7.92 kN/m 24 kN/m³ x 0.1 x 1.1 = 2.64 kN/m

Beam 24 kN/m³ x 0.2 x 0.4 = 1.92 kN/m

Roof Load 0 kN/m²x 1.7 = 0 kN/m 0 kN/m²x 0.83 = 0 kN/m

Wall 10cm 1.2 kN/m²x 3.3 = 3.96 kN/m 1.2 kN/m²x 3.3 = 3.96 kN/m

Wall 20cm 0 kN/m²x 0 = 0 kN/m 0 kN/m²x 0 = 0 kN/m

Floor Finish 1.5 kN/m²x 3.3 = 4.95 kN/m 1.5 kN/m²x 1.1 = 1.65 kN/m

Total Dead Load ### kN/m 8.3 kN/m

Live Load or Imposed load

Floor LL 4 kN/m² x 3.3 m = 13.2 kN/m 4 kN/m² x 1.1 m = 4.4 kN/m

Roof LL 0 kN/m² x 1.7 m = 0 kN/m 0 kN/m² x 0.83 m = 0 kN/m

Total live Load 13 kN/m 4.4 kN/m

Triangle or Trapezoidal Design Load

(1.4 x 18.75) + (1.6 x 13.2) = ### kN/m (1.4 x 8.25) + (1.6 x 4.4) = ### kN/m

Convert Trapezoidal load to uniformly distributed load

Uniformly distributed 47.4 x 1 = 47 kN/m 18.6 x 1 = 19 kN/m

Total uniformly distributed load

47.4 + 18.6 = 65.96 kN/m

Page 10: Design Beam

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BS8110 REF. CALCULATION OUTPUT

B Bending Moment

Max moment at suppo = - ql²/12 = ### kN/m

Max moment at mid s = ql²/24 = ### kN/m

C -Beam Section

h=L

toL

=6600

to6600

» h= 471.43 mm » h= 400 mm10 15 10 15

b=(0.4 to 0.5)h= (0.4 to 0.5)400 » b= 212.14 mm » b= 200 mm

Cover: C= 25 mm 8 mm ; 20 mm

d= = 400 - 25 - 4 - 10 = 361 mm d'= 35 mm

D-Define Steel Area

Assume fcu= 30 N/mm² ; fy v= 250 N/mm² fy = 390 N/mm²

a -Define Steel Area at Support Mmax= 239.43 kNm

» Compression Steel Area

Existing Steel Area 2 T 20 » 628

» Tension Steel Area

Existing Steel Area 4 T 20 » ### 0 T 25 » 0

Total Steel Area 1884 mm²

» P=100(As,req / bd) 2.36 > 0.13 < 4 » OK

b -Define Steel Area at Mid spanMmax= 119.72 kNm

» Compression Steel Area

Existing Steel Area 2 T 20 » 628

» Tension Steel Area

Existing Steel Area 4 T 20 » ###

Total Steel Area 1884 mm²

» P=100(As,req / bd) 2.36 > 0.13 < 4 » OK

Msup

Mmid

;Assume Steel Bar Ø DR= DT=

h - C - DR/2 - DT/2

As'= mm2

As= mm2 As'= mm2

As'= mm2

As= mm2

Page 11: Design Beam

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BS8110 REF. CALCULATION OUTPUT

c -Link or Stirrup

Convert Trapezoidal load to uniformly distributed load for bending moment

Left Side of the beam Right Side of the beam

Uniformly distributed 47.4 x 1 = 47 kN/m 18.6 x 1 = 19 kN/m

Total uniformly distributed load

47.4 + 18.6 = 65.96 kN/m

Max Shear at Support

= ql/2 = 218 kN

= / bd = 3.01 N/mm²

Max Shear Stress = 4.38 N/mm²

= (0.79/1.25) [(100As/bd)^(1/3)] [(400/d)^(1/4)] [(fcu/25)^(1/3)]

= 0.95 N/mm²

+0.4= 1.35 N/mm²

» Vc+0.4 Vs < 0.8(fcu^(1/2))

6 mm » Area of link Asv= 57

» Link Spacin = 30 mm » 30 mm

Hence R6@30

» Existing Link Ø 6 mm @ 150 mm not enough

Vmax

Vstress Vmax

0.8(fcu^(1/2))

Vcapacity

Vcapacity

Asv≥(bv Sv(vs-vc))/0.87fy Assume ø mm2

Sv≤(Asv x 0.87fy)/(bv(vs-vc))

Page 12: Design Beam

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BS8110 REF. CALCULATION OUTPUT

Shear at L/4

= = 163 kN

= / bd = 2.26 N/mm²

Max Shear Stress = 1.6 N/mm²

= (0.79/1.25) [(100As/bd)^(1/3)] [(400/d)^(1/4)] [(fcu/25)^(1/3)]

= 0.95 N/mm²

+0.4= 1.35 N/mm²

» Vc+0.4 Vs < 0.8(fcu^(1/2))

6 mm » Area of link Asv= 57

» Link Spacin = 47 mm » 50 mm

Hence R6@50

» Existing Link Ø 6 mm @ 150 mm not enough

d -Check Deflection

=120 x

= 4.59200 x 130321

fs =5

fy =2

x 390 x1884

= 260 (Service Stress)8 3 1884

modification factor = 0.55 +477 - fs

= 1120

Bassic span/depth = 26 ( table3.9 in Code BS8110 Part 1 1985)

Allowable span/dep = 26 x 0.987 = 25.674

Actual span/depth = l /### = 6600 / 250 = 26.4 mm

Vmax qll/4 / 2

Vstress Vmax

0.8(fcu^(1/2))

Vcapacity

Vcapacity

Asv≥(bv Sv(vs-vc))/0.87fy Assume Ø mm2

Sv≤(Asv x 0.87fy)/(bv(vs-vc))

Mmax 106

bd2

As,req

As,pro

(0.9+(M / bd2))

Page 13: Design Beam

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» »Allowable span/depth= 25.67 <Actual span/depth= 26 » NO

BS8110 REF. CALCULATION OUTPUT

e -Check Cracking

Refer 3.12.11.2.3

1/ CLear distance between horizontal tension bars

Allowable clear distance between bars

= 155 (table 3.28)

=

= 47 mm < 155 OK

Clear Distance between the face of the beam and nearest longitudinal bar in tension

=

y =

= 43 mm

Allowable distance

= 155x0.5 = 77.5 mm

» = 50.81 mm < 77.5 bar should be provided in side faces of beam to control cracking

Distance between bars

S1 (b-2(cover)-2(Ølinks)-2(Øbar))/2

S2 ((y2+y2)^(1/2))-(Øbar/2)

cover+Ølink+(Øbar/2)

S2

Page 14: Design Beam

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Sb ≤ 250 mm

Minimum size bar

Ø >

> 11.32 mm Provide DB12 @ 250

((Sbb/fy)^(1/2))

Page 15: Design Beam

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Check Existing Section of Ground Beam GB9 (Along Grid E from Grid 7'-9')

BS8110 REF. CALCULATION OUTPUT

I/ Check ExistiGB9 effective span= 7.7 m

A Loading Slab Panel 7.7 x 2.2 m and 7.7 x 1.7 m and 0.1 mTHK

Dead Load

Left Side of the beam Right Side of the beam

Slab 24 kN/m³ x 0.1 x 2.2 = 5.28 kN/m 24 kN/m³ x 0.1 x 1.65 = 3.96 kN/m

Beam 24 kN/m³ x 0.2 x 0.4 = 1.92 kN/m

Roof Load 0 kN/m²x 1.7 = 0 kN/m 0 kN/m²x 0.83 = 0 kN/m

Wall 10cm 1.2 kN/m²x 3.3 = 3.96 kN/m 1.2 kN/m²x 3.3 = 3.96 kN/m

Wall 20cm 0 kN/m²x 0 = 0 kN/m 0 kN/m²x 0 = 0 kN/m

Floor Finish 1.5 kN/m²x 2.2 = 3.3 kN/m 1.5 kN/m²x 1.65 = 2.47 kN/m

Total Dead Load ### kN/m ### kN/m

Live Load or Imposed load

Floor LL 4 kN/m² x 2.2 m = 8.8 kN/m 4 kN/m² x 1.65 m = 6.6 kN/m

Roof LL 0 kN/m² x 1.7 m = 0 kN/m 0 kN/m² x 0.83 m = 0 kN/m

Total live Load 8.8 kN/m 6.6 kN/m

Triangle or Trapezoidal Design Load

(1.4 x 14.46) + (1.6 x 8.8) = ### kN/m (1.4 x 10.4) + (1.6 x 6.6) = ### kN/m

Convert Trapezoidal load to uniformly distributed load

Uniformly distributed 34.3 x 1 = 34 kN/m 25.1 x 1 = 25 kN/m

Total uniformly distributed load

34.3 + 25.1 = 59.44 kN/m

Page 16: Design Beam

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BS8110 REF. CALCULATION OUTPUT

B Bending Moment

Max moment at suppo = - ql²/12 = ### kN/m

Max moment at mid s = ql²/24 = ### kN/m

C -Beam Section

h=L

toL

=7700

to7700

» h= 550 mm » h= 400 mm10 15 10 15

b=(0.4 to 0.5)h= (0.4 to 0.5)400 » b= 247.5 mm » b= 200 mm

Cover: C= 25 mm 8 mm ; 20 mm

d= = 400 - 25 - 4 - 10 = 361 mm d'= 35 mm

D-Define Steel Area

Assume fcu= 30 N/mm² ; fy v= 250 N/mm² fy = 390 N/mm²

a -Define Steel Area at Support Mmax= 293.67 kNm

» Compression Steel Area

Existing Steel Area 2 T 25 » 981

» Tension Steel Area

Existing Steel Area 2 T 20 » 628 3 T 25 » ###

Total Steel Area 3081 mm²

» P=100(As,req / bd) 3.85 > 0.13 < 4 » OK

b -Define Steel Area at Mid spanMmax= 146.83 kNm

» Compression Steel Area

Existing Steel Area 2 T 20 » 628

» Tension Steel Area

Existing Steel Area 6 T 25 » ###

Total Steel Area 3572 mm²

Msup

Mmid

;Assume Steel Bar Ø DR= DT=

h - C - DR/2 - DT/2

As'= mm2

As= mm2 As'= mm2

As'= mm2

As= mm2

Page 17: Design Beam

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» P=100(As,req / bd) 4.46 > 0.13 < 4 » OK

BS8110 REF. CALCULATION OUTPUT

c -Link or Stirrup

Convert Trapezoidal load to uniformly distributed load for bending moment

Left Side of the beam Right Side of the beam

Uniformly distributed 34.3 x 1 = 34 kN/m 25.1 x 1 = 25 kN/m

Total uniformly distributed load

34.3 + 25.1 = 59.44 kN/m

Max Shear at Support

= ql/2 = 229 kN

= / bd = 3.17 N/mm²

Max Shear Stress = 4.38 N/mm²

= (0.79/1.25) [(100As/bd)^(1/3)] [(400/d)^(1/4)] [(fcu/25)^(1/3)]

= 1.11 N/mm²

+0.4= 1.51 N/mm²

» Vc+0.4 Vs < 0.8(fcu^(1/2))

6 mm » Area of link Asv= 57

» Link Spacin = 30 mm » 30 mm

Hence R6@30

» Existing Link Ø 6 mm @ 150 mm not enough

Vmax

Vstress Vmax

0.8(fcu^(1/2))

Vcapacity

Vcapacity

Asv≥(bv Sv(vs-vc))/0.87fy Assume ø mm2

Sv≤(Asv x 0.87fy)/(bv(vs-vc))

Page 18: Design Beam

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BS8110 REF. CALCULATION OUTPUT

Shear at L/4

= = 172 kN

= / bd = 2.38 N/mm²

Max Shear Stress = 2 N/mm²

= (0.79/1.25) [(100As/bd)^(1/3)] [(400/d)^(1/4)] [(fcu/25)^(1/3)]

= 1.11 N/mm²

+0.4= 1.51 N/mm²

» Vc+0.4 Vs < 0.8(fcu^(1/2))

6 mm » Area of link Asv= 57

» Link Spacin = 49 mm » 50 mm

Hence R6@50

» Existing Link Ø 6 mm @ 150 mm not enough

d -Check Deflection

=147 x

= 5.63200 x 130321

fs =5

fy =2

x 390 x3572

= 260 (Service Stress)8 3 3571.8

modification factor = 0.55 +477 - fs

= 0.91120

Bassic span/depth = 26 ( table3.9 in Code BS8110 Part 1 1985)

Vmax qll/4 / 2

Vstress Vmax

0.8(fcu^(1/2))

Vcapacity

Vcapacity

Asv≥(bv Sv(vs-vc))/0.87fy Assume Ø mm2

Sv≤(Asv x 0.87fy)/(bv(vs-vc))

Mmax 106

bd2

As,req

As,pro

(0.9+(M / bd2))

Page 19: Design Beam

19

Allowable span/dep = 26 x 0.907 = 23.573

Actual span/depth = l /### = 7700 / 250 = 30.8 mm

» »Allowable span/depth= 23.57 <Actual span/depth= 31 » NO

BS8110 REF. CALCULATION OUTPUT

e -Check Cracking

Refer 3.12.11.2.3

1/ CLear distance between horizontal tension bars

Allowable clear distance between bars

= 155 (table 3.28)

=

= 42 mm < 155 OK

Clear Distance between the face of the beam and nearest longitudinal bar in tension

=

y =

= 45.5 mm

Allowable distance

= 155x0.5 = 77.5 mm

» = 51.85 mm < 77.5 bar should be provided in side faces of beam to control cracking

Distance between bars

S1 (b-2(cover)-2(Ølinks)-2(Øbar))/2

S2 ((y2+y2)^(1/2))-(Øbar/2)

cover+Ølink+(Øbar/2)

S2

Page 20: Design Beam

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Sb ≤ 250 mm

Minimum size bar Ø >

> 11.323 mm

Provide DB12 @ 250

((Sbb/fy)^(1/2))

Page 21: Design Beam

21

Check Existing Section of First Floor Beam B2a (Along Grid E from Grid 7'-9')

BS8110 REF. CALCULATION OUTPUT

I/ Check ExistiB2a effective span= 7.7 m

A Loading Slab Panel 7.7 x 2.2 m and 7.7 x 1.7 m and 0.1 mTHK

Dead Load

Left Side of the beam Right Side of the beam

Slab 24 kN/m³ x 0.12 x 2.2 = 6.34 kN/m 24 kN/m³ x 0.12 x 1.65 = 4.75 kN/m

Beam 24 kN/m³ x 0.25 x 0.6 = 3.6 kN/m

Roof Load 0 kN/m²x 1.7 = 0 kN/m 0 kN/m²x 0.83 = 0 kN/m

Wall 10cm 1.2 kN/m²x 3.3 = 3.96 kN/m 1.2 kN/m²x 3.3 = 3.96 kN/m

Wall 20cm 0 kN/m²x 0 = 0 kN/m 0 kN/m²x 0 = 0 kN/m

Floor Finish 1.5 kN/m²x 2.2 = 3.3 kN/m 1.5 kN/m²x 1.65 = 2.47 kN/m

Total Dead Load ### kN/m ### kN/m

Live Load or Imposed load

Floor LL 4 kN/m² x 2.2 m = 8.8 kN/m 4 kN/m² x 1.65 m = 6.6 kN/m

Roof LL 0 kN/m² x 1.7 m = 0 kN/m 0 kN/m² x 0.83 m = 0 kN/m

Total live Load 8.8 kN/m 6.6 kN/m

Triangle or Trapezoidal Design Load

(1.4 x 17.2) + (1.6 x 8.8) = ### kN/m (1.4 x 11.19) + (1.6 x 6.6) = ### kN/m

Convert Trapezoidal load to uniformly distributed load

Uniformly distributed 38.2 x 1 = 38 kN/m 26.2 x 1 = 26 kN/m

Total uniformly distributed load

38.2 + 26.2 = 64.38 kN/m

Page 22: Design Beam

22

BS8110 REF. CALCULATION OUTPUT

B Bending Moment

Max moment at suppo = - ql²/12 = ### kN/m

Max moment at mid s = ql²/24 = ### kN/m

C -Beam Section

h=L

toL

=7700

to7700

» h= 550 mm » h= 600 mm10 15 10 15

b=(0.4 to 0.5)h= (0.4 to 0.5)600 » b= 247.5 mm » b= 250 mm

Cover: C= 25 mm 8 mm ; 20 mm

d= = 600 - 25 - 4 - 10 = 561 mm d'= 35 mm

D-Define Steel Area

Assume fcu= 30 N/mm² ; fy v= 250 N/mm² fy = 390 N/mm²

a -Define Steel Area at Support Mmax= 318.07 kNm

» Compression Steel Area

Existing Steel Area 2 T 25 » 981

» Tension Steel Area

Existing Steel Area 2 T 20 » 628 3 T 25 » ###

Total Steel Area 3081 mm²

» P=100(As,req / bd) 2.05 > 0.13 < 4 » OK

b -Define Steel Area at Mid spanMmax= 159.04 kNm

» Compression Steel Area

Existing Steel Area 2 T 20 » 628

» Tension Steel Area

Existing Steel Area 6 T 25 » ###

Total Steel Area 3572 mm²

Msup

Mmid

;Assume Steel Bar Ø DR= DT=

h - C - DR/2 - DT/2

As'= mm2

As= mm2 As'= mm2

As'= mm2

As= mm2

Page 23: Design Beam

23

» P=100(As,req / bd) 2.38 > 0.13 < 4 » OK

BS8110 REF. CALCULATION OUTPUT

c -Link or Stirrup

Convert Trapezoidal load to uniformly distributed load for bending moment

Left Side of the beam Right Side of the beam

Uniformly distributed 38.2 x 1 = 38 kN/m 26.2 x 1 = 26 kN/m

Total uniformly distributed load

38.2 + 26.2 = 64.38 kN/m

Max Shear at Support

= ql/2 = 248 kN

= / bd = 1.77 N/mm²

Max Shear Stress = 4.38 N/mm²

= (0.79/1.25) [(100As/bd)^(1/3)] [(400/d)^(1/4)] [(fcu/25)^(1/3)]

= 0.80 N/mm²

+0.4= 1.20 N/mm²

» Vc+0.4 Vs < 0.8(fcu^(1/2))

8 mm » Area of link Asv= 101

» Link Spacin = 90 mm » 90 mm

Hence R8@90

» Existing Link Ø 8 mm @ 125 mm not enough

Vmax

Vstress Vmax

0.8(fcu^(1/2))

Vcapacity

Vcapacity

Asv≥(bv Sv(vs-vc))/0.87fy Assume ø mm2

Sv≤(Asv x 0.87fy)/(bv(vs-vc))

Page 24: Design Beam

24

Shear at L/4

= = 186 kN

= / bd = 1.33 N/mm²

Max Shear Stress = 2 N/mm²

= (0.79/1.25) [(100As/bd)^(1/3)] [(400/d)^(1/4)] [(fcu/25)^(1/3)]

= 0.80 N/mm²

+0.4= 1.20 N/mm²

» Vc+0.4 Vs < 0.8(fcu^(1/2))

8 mm » Area of link Asv= 101

» Link Spacin = 166 mm » 160 mm

Hence R8@160

» Existing Link Ø 8 mm @ 125 mm safe enough

d -Check Deflection

=159 x

= 2.02250 x 314721

fs =5

fy =2

x 390 x3572

= 260 (Service Stress)8 3 3571.8

modification factor = 0.55 +477 - fs

= 1.54120

Bassic span/depth = 26 ( table3.9 in Code BS8110 Part 1 1985)

Allowable span/dep = 26 x 1.544 = 40.145

Actual span/depth = l /### = 7700 / 250 = 30.8 mm

» »Allowable span/depth= 40.15 >Actual span/depth= 31 » OK

Vmax qll/4 / 2

Vstress Vmax

0.8(fcu^(1/2))

Vcapacity

Vcapacity

Asv≥(bv Sv(vs-vc))/0.87fy Assume Ø mm2

Sv≤(Asv x 0.87fy)/(bv(vs-vc))

Mmax 106

bd2

As,req

As,pro

(0.9+(M / bd2))

Page 25: Design Beam

25

e -Check Cracking

Refer 3.12.11.2.3

1/ CLear distance between horizontal tension bars

Allowable clear distance between bars

= 155 (table 3.28)

=

= 67 mm < 155 OK

Clear Distance between the face of the beam and nearest longitudinal bar in tension

=

y =

= 45.5 mm

Allowable distance

= 155x0.5 = 77.5 mm

» = 51.85 mm < 77.5 bar should be provided in side faces of beam to control cracking

Distance between bars

Sb ≤ 250 mm

S1 (b-2(cover)-2(Ølinks)-2(Øbar))/2

S2 ((y2+y2)^(1/2))-(Øbar/2)

cover+Ølink+(Øbar/2)

S2

Page 26: Design Beam

26

Minimum size bar

Ø >

> 12.66 mm

Provide DB12 @ 250

((Sbb/fy)^(1/2))

Page 27: Design Beam

27

Check Existing Section of Roof Floor Beam RB1A (Along Grid H from Grid 2-4)

BS8110 REF. CALCULATION OUTPUT

I/ Check ExistiRB1A effective span= 6.6 m

A Loading Slab Panel 6.6 x 1.65 m and 6.6 x 1.7 m and 0.1 mTHK

Dead Load

Left Side of the beam Right Side of the beam

Slab 24 kN/m³ x 0.12 x 1.65 = 4.75 kN/m 24 kN/m³ x 0.12 x 1.65 = 4.75 kN/m

Beam 24 kN/m³ x 0.2 x 0.4 = 1.92 kN/m

Roof Load 1.5 kN/m²x 1.7 = 2.55 kN/m 1.5 kN/m²x 0.83 = 1.24 kN/m

Wall 10cm 0 kN/m²x 3.3 = 0 kN/m 0 kN/m²x 3.3 = 0 kN/m

Wall 20cm 0 kN/m²x 0 = 0 kN/m 0 kN/m²x 0 = 0 kN/m

Floor Finish 1.5 kN/m²x 1.65 = 2.47 kN/m 1.5 kN/m²x 1.65 = 2.47 kN/m

Total Dead Load ### kN/m 8.5 kN/m

Live Load or Imposed load

Floor LL 1.5 kN/m² x 1.65 m = 2.47 kN/m 1.5 kN/m² x 1.65 m = 2.47 kN/m

Roof LL 1.5 kN/m² x 1.7 m = 2.55 kN/m 1.5 kN/m² x 0.83 m = 1.24 kN/m

Total live Load 5 kN/m 3.7 kN/m

Triangle or Trapezoidal Design Load

(1.4 x 11.7) + (1.6 x 5.03) = ### kN/m (1.4 x 8.47) + (1.6 x 3.72) = ### kN/m

Convert Trapezoidal load to uniformly distributed load

Uniformly distributed 24.4 x 1 = 24 kN/m 17.8 x 1 = 18 kN/m

Total uniformly distributed load

24.4 + 17.8 = 42.23 kN/m

Page 28: Design Beam

28

BS8110 REF. CALCULATION OUTPUT

B Bending Moment

Max moment at suppo = - ql²/12 = ### kN/m

Max moment at mid s = ql²/24 = 76.64 kN/m

C -Beam Section

h=L

toL

=6600

to6600

» h= 471.43 mm » h= 400 mm10 15 10 15

b=(0.4 to 0.5)h= (0.4 to 0.5)400 » b= 212.14 mm » b= 200 mm

Cover: C= 25 mm 8 mm ; 20 mm

d= = 400 - 25 - 4 - 10 = 361 mm d'= 35 mm

D-Define Steel Area

Assume fcu= 30 N/mm² ; fy v= 250 N/mm² fy = 390 N/mm²

a -Define Steel Area at Support Mmax= 153.29 kNm

» Compression Steel Area

Existing Steel Area 2 T 20 » 628

» Tension Steel Area

Existing Steel Area 2 T 20 » 628 2 T 16 » 402

Total Steel Area 1658 mm²

» P=100(As,req / bd) 2.07 > 0.13 < 4 » OK

b -Define Steel Area at Mid spanMmax= 76.64 kNm

» Compression Steel Area

Existing Steel Area 2 T 20 » 628

» Tension Steel Area

Existing Steel Area 4 T 20 » ###

Total Steel Area 1884 mm²

Msup

Mmid

;Assume Steel Bar Ø DR= DT=

h - C - DR/2 - DT/2

As'= mm2

As= mm2 As'= mm2

As'= mm2

As= mm2

Page 29: Design Beam

29

» P=100(As,req / bd) 2.36 > 0.13 < 4 » OK

BS8110 REF. CALCULATION OUTPUT

c -Link or Stirrup

Convert Trapezoidal load to uniformly distributed load for bending moment

Left Side of the beam Right Side of the beam

Uniformly distributed 24.4 x 1 = 24 kN/m 17.8 x 1 = 18 kN/m

Total uniformly distributed load

24.4 + 17.8 = 42.23 kN/m

Max Shear at Support

= ql/2 = 139 kN

= / bd = 1.93 N/mm²

Max Shear Stress = 4.38 N/mm²

= (0.79/1.25) [(100As/bd)^(1/3)] [(400/d)^(1/4)] [(fcu/25)^(1/3)]

= 0.91 N/mm²

+0.4= 1.31 N/mm²

» Vc+0.4 Vs < 0.8(fcu^(1/2))

8 mm » Area of link Asv= 101

» Link Spacin = 107 mm » 100 mm

Hence R8@100

» Existing Link Ø 8 mm @ 125 mm not enough

Vmax

Vstress Vmax

0.8(fcu^(1/2))

Vcapacity

Vcapacity

Asv≥(bv Sv(vs-vc))/0.87fy Assume ø mm2

Sv≤(Asv x 0.87fy)/(bv(vs-vc))

Page 30: Design Beam

30

Shear at L/4

= = 105 kN

= / bd = 1.45 N/mm²

Max Shear Stress = 1.6 N/mm²

= (0.79/1.25) [(100As/bd)^(1/3)] [(400/d)^(1/4)] [(fcu/25)^(1/3)]

= 0.91 N/mm²

+0.4= 1.31 N/mm²

» Vc+0.4 Vs < 0.8(fcu^(1/2))

8 mm » Area of link Asv= 101

» Link Spacin = 202 mm » 200 mm

Hence R8@200

» Existing Link Ø 8 mm @ 125 mm safe enough

d -Check Deflection

=76.6 x

= 2.94200 x 130321

fs =5

fy =2

x 390 x1884

= 260 (Service Stress)8 3 1884

modification factor = 0.55 +477 - fs

= 1.23120

Bassic span/depth = 26 ( table3.9 in Code BS8110 Part 1 1985)

Allowable span/dep = 26 x 1.233 = 32.065

Actual span/depth = l /### = 6600 / 250 = 26.4 mm

» »Allowable span/depth= 32.07 >Actual span/depth= 26 » OK

Vmax qll/4 / 2

Vstress Vmax

0.8(fcu^(1/2))

Vcapacity

Vcapacity

Asv≥(bv Sv(vs-vc))/0.87fy Assume Ø mm2

Sv≤(Asv x 0.87fy)/(bv(vs-vc))

Mmax 106

bd2

As,req

As,pro

(0.9+(M / bd2))

Page 31: Design Beam

31

e -Check Cracking

Refer 3.12.11.2.3 BS8110

1/ CLear distance between horizontal tension bars

Allowable clear distance between bars

= 155 (table 3.28)

=

= 47 mm < 155 OK

Clear Distance between the face of the beam and nearest longitudinal bar in tension

=

y =

= 43 mm

Allowable distance

= 155x0.5 = 77.5 mm

» = 50.81 mm < 77.5 bar should be provided in side faces of beam to control cracking

Distance between bars

Sb ≤ 250 mm

S1 (b-2(cover)-2(Ølinks)-2(Øbar))/2

S2 ((y2+y2)^(1/2))-(Øbar/2)

cover+Ølink+(Øbar/2)

S2

Page 32: Design Beam

32

Minimum size bar

Ø >

> 11.32 mm

Provide DB12 @ 250

((Sbb/fy)^(1/2))

Page 33: Design Beam

33

Check Existing Section of Roof Floor Beam RB15B (Along Grid E from Grid 1-5)

BS8110 REF. CALCULATION OUTPUT

I/ Check ExistiRB15B effective span= 9.9 m

A Loading Slab Panel 9.9 x 2.2 m and 9.9 x 1.7 m and 0.1 mTHK

Dead Load

Left Side of the beam Right Side of the beam

Slab 24 kN/m³ x 0.12 x 2.2 = 6.34 kN/m 24 kN/m³ x 0.12 x 1.65 = 4.75 kN/m

Beam 24 kN/m³ x 0.25 x 0.6 = 3.6 kN/m

Roof Load 1.5 kN/m²x 1.7 = 2.55 kN/m 1.5 kN/m²x 0.83 = 1.24 kN/m

Wall 10cm 0 kN/m²x 3.3 = 0 kN/m 0 kN/m²x 3.3 = 0 kN/m

Wall 20cm 0 kN/m²x 0 = 0 kN/m 0 kN/m²x 0 = 0 kN/m

Floor Finish 1.5 kN/m²x 2.2 = 3.3 kN/m 1.5 kN/m²x 1.65 = 2.47 kN/m

Total Dead Load ### kN/m 8.5 kN/m

Live Load or Imposed load

Floor LL 1.5 kN/m² x 2.2 m = 3.3 kN/m 1.5 kN/m² x 1.65 m = 2.47 kN/m

Roof LL 1.5 kN/m² x 1.7 m = 2.55 kN/m 1.5 kN/m² x 0.83 m = 1.24 kN/m

Total live Load 5.9 kN/m 3.7 kN/m

Triangle or Trapezoidal Design Load

(1.4 x 15.79) + (1.6 x 5.85) = ### kN/m (1.4 x 8.47) + (1.6 x 3.72) = ### kN/m

Convert Trapezoidal load to uniformly distributed load

Uniformly distributed 31.5 x 1 = 31 kN/m 17.8 x 1 = 18 kN/m

Total uniformly distributed load

31.5 + 17.8 = 49.27 kN/m

Page 34: Design Beam

34

BS8110 REF. CALCULATION OUTPUT

B Bending Moment

Max moment at suppo = - ql²/12 = ### kN/m

Max moment at mid s = ql²/24 = ### kN/m

C -Beam Section

h=L

toL

=9900

to9900

» h= 707.14 mm » h= 600 mm10 15 10 15

b=(0.4 to 0.5)h= (0.4 to 0.5)600 » b= 318.21 mm » b= 250 mm

Cover: C= 25 mm 8 mm ; 20 mm

d= = 600 - 25 - 4 - 10 = 561 mm d'= 35 mm

D-Define Steel Area

Assume fcu= 30 N/mm² ; fy v= 250 N/mm² fy = 390 N/mm²

a -Define Steel Area at Support Mmax= 402.44 kNm

» Compression Steel Area

Existing Steel Area 2 T 25 » 981

» Tension Steel Area

Existing Steel Area 2 T 20 » 628 3 T 25 » ###

Total Steel Area 3081 mm²

» P=100(As,req / bd) 2.05 > 0.13 < 4 » OK

b -Define Steel Area at Mid spanMmax= 201.22 kNm

» Compression Steel Area

Existing Steel Area 2 T 20 » 628

» Tension Steel Area

Existing Steel Area 6 T 25 » ###

Total Steel Area 3572 mm²

Msup

Mmid

;Assume Steel Bar Ø DR= DT=

h - C - DR/2 - DT/2

As'= mm2

As= mm2 As'= mm2

As'= mm2

As= mm2

Page 35: Design Beam

35

» P=100(As,req / bd) 2.38 > 0.13 < 4 » OK

BS8110 REF. CALCULATION OUTPUT

c -Link or Stirrup

Convert Trapezoidal load to uniformly distributed load for bending moment

Left Side of the beam Right Side of the beam

Uniformly distributed 31.5 x 1 = 31 kN/m 17.8 x 1 = 18 kN/m

Total uniformly distributed load

31.5 + 17.8 = 49.27 kN/m

Max Shear at Support

= ql/2 = 244 kN

= / bd = 1.74 N/mm²

Max Shear Stress = 4.38 N/mm²

= (0.79/1.25) [(100As/bd)^(1/3)] [(400/d)^(1/4)] [(fcu/25)^(1/3)]

= 0.80 N/mm²

+0.4= 1.20 N/mm²

» Vc+0.4 Vs < 0.8(fcu^(1/2))

8 mm » Area of link Asv= 101

» Link Spacin = 93 mm » 90 mm

Hence R8@90

» Existing Link Ø 8 mm @ 125 mm not enough

Vmax

Vstress Vmax

0.8(fcu^(1/2))

Vcapacity

Vcapacity

Asv≥(bv Sv(vs-vc))/0.87fy Assume ø mm2

Sv≤(Asv x 0.87fy)/(bv(vs-vc))

Page 36: Design Beam

36

Shear at L/4

= = 183 kN

= / bd = 1.3 N/mm²

Max Shear Stress = 2 N/mm²

= (0.79/1.25) [(100As/bd)^(1/3)] [(400/d)^(1/4)] [(fcu/25)^(1/3)]

= 0.80 N/mm²

+0.4= 1.20 N/mm²

» Vc+0.4 Vs < 0.8(fcu^(1/2))

8 mm » Area of link Asv= 101

» Link Spacin = 173 mm » 170 mm

Hence R8@170

» Existing Link Ø 8 mm @ 125 mm safe enough

d -Check Deflection

=201 x

= 2.56250 x 314721

fs =5

fy =2

x 390 x3572

= 260 (Service Stress)8 3 3571.8

modification factor = 0.55 +477 - fs

= 1.34120

Bassic span/depth = 26 ( table3.9 in Code BS8110 Part 1 1985)

Allowable span/dep = 26 x 1.336 = 34.727

Actual span/depth = l /### = 9900 / 250 = 39.6 mm

» »Allowable span/depth= 34.73 <Actual span/depth= 40 » NO

Vmax qll/4 / 2

Vstress Vmax

0.8(fcu^(1/2))

Vcapacity

Vcapacity

Asv≥(bv Sv(vs-vc))/0.87fy Assume Ø mm2

Sv≤(Asv x 0.87fy)/(bv(vs-vc))

Mmax 106

bd2

As,req

As,pro

(0.9+(M / bd2))

Page 37: Design Beam

37

e -Check Cracking

Refer 3.12.11.2.3

1/ CLear distance between horizontal tension bars

Allowable clear distance between bars

= 155 (table 3.28)

=

= 67 mm < 155 OK

Clear Distance between the face of the beam and nearest longitudinal bar in tension

=

y =

= 45.5 mm

Allowable distance

= 155x0.5 = 77.5 mm

» = 51.85 mm < 77.5 bar should be provided in side faces of beam to control cracking

Distance between bars

Sb ≤ 250 mm

S1 (b-2(cover)-2(Ølinks)-2(Øbar))/2

S2 ((y2+y2)^(1/2))-(Øbar/2)

cover+Ølink+(Øbar/2)

S2

Page 38: Design Beam

38

Minimum size bar

Ø >

> 12.66 mm

Provide DB12 @ 250

((Sbb/fy)^(1/2))

Page 39: Design Beam

39

Check Existing Section of First Floor Beam B1 (Along Grid G from Grid 13-15)

BS8110 REF. CALCULATION OUTPUT

I/ Check ExistiB1 effective span= 6.6 m

A Loading Slab Panel 6.6 x 2.2 m and 6.6 x 0 m and 0.1 mTHK

Dead Load

Left Side of the beam Right Side of the beam

Slab 24 kN/m³ x 0.12 x 2.2 = 6.34 kN/m 24 kN/m³ x 0.12 x 0 = 0 kN/m

Beam 24 kN/m³ x 0.2 x 0.3 = 1.44 kN/m

Roof Load 0 kN/m²x 1.7 = 0 kN/m 0 kN/m²x 0.83 = 0 kN/m

Wall 10cm 0 kN/m²x 3.3 = 0 kN/m 0 kN/m²x 3.3 = 0 kN/m

Wall 20cm 2.3 kN/m²x 4.3 = 9.89 kN/m 2.3 kN/m²x 0 = 0 kN/m

Floor Finish 1.5 kN/m²x 2.2 = 3.3 kN/m 1.5 kN/m²x 0 = 0 kN/m

Total Dead Load ### kN/m 0.0 kN/m

Live Load or Imposed load

Floor LL 4 kN/m² x 2.2 m = 8.8 kN/m 4 kN/m² x 0 m = 0 kN/m

Roof LL 0 kN/m² x 1.7 m = 0 kN/m 0 kN/m² x 0.83 m = 0 kN/m

Total live Load 8.8 kN/m 0 kN/m

Triangle or Trapezoidal Design Load

(1.4 x 20.97) + (1.6 x 8.8) = ### kN/m (1.4 x 0) + (1.6 x 0) = 0.0 kN/m

Convert Trapezoidal load to uniformly distributed load

Uniformly distributed 43.4 x 1 = 43 kN/m 0.0 x 1 = 0 kN/m

Total uniformly distributed load

43.4 + 0 = 43.43 kN/m

Page 40: Design Beam

40

BS8110 REF. CALCULATION OUTPUT

B Bending Moment

Max moment at suppo = - ql²/12 = ### kN/m

Max moment at mid s = ql²/24 = 78.83 kN/m

C -Beam Section

h=L

toL

=6600

to6600

» h= 471.43 mm » h= 300 mm10 15 10 15

b=(0.4 to 0.5)h= (0.4 to 0.5)300 » b= 212.14 mm » b= 200 mm

Cover: C= 25 mm 8 mm ; 20 mm

d= = 300 - 25 - 4 - 10 = 261 mm d'= 35 mm

D-Define Steel Area

Assume fcu= 30 N/mm² ; fy v= 250 N/mm² fy = 390 N/mm²

a -Define Steel Area at Support Mmax= 157.66 kNm

» Compression Steel Area

Existing Steel Area 2 T 16 » 402

» Tension Steel Area

Existing Steel Area 4 T 20 » ### 0 T 25 » 0

Total Steel Area 1658 mm²

» P=100(As,req / bd) 2.76 > 0.13 < 4 » OK

b -Define Steel Area at Mid spanMmax= 78.83 kNm

» Compression Steel Area

Existing Steel Area 2 T 16 » 628

» Tension Steel Area

Existing Steel Area 3 T 16 » 603

Total Steel Area 1231 mm²

Msup

Mmid

;Assume Steel Bar Ø DR= DT=

h - C - DR/2 - DT/2

As'= mm2

As= mm2 As'= mm2

As'= mm2

As= mm2

Page 41: Design Beam

41

» P=100(As,req / bd) 2.05 > 0.13 < 4 » OK

BS8110 REF. CALCULATION OUTPUT

c -Link or Stirrup

Convert Trapezoidal load to uniformly distributed load for bending moment

Left Side of the beam Right Side of the beam

Uniformly distributed 43.4 x 1 = 43 kN/m 0.0 x 1 = 0 kN/m

Total uniformly distributed load

43.4 + 0 = 43.43 kN/m

Max Shear at Support

= ql/2 = 143 kN

= / bd = 2.75 N/mm²

Max Shear Stress = 4.38 N/mm²

= (0.79/1.25) [(100As/bd)^(1/3)] [(400/d)^(1/4)] [(fcu/25)^(1/3)]

= 1.09 N/mm²

+0.4= 1.49 N/mm²

» Vc+0.4 Vs < 0.8(fcu^(1/2))

8 mm » Area of link Asv= 101

» Link Spacin = 66 mm » 70 mm

Hence R8@70

» Existing Link Ø 8 mm @ 125 mm not enough

Vmax

Vstress Vmax

0.8(fcu^(1/2))

Vcapacity

Vcapacity

Asv≥(bv Sv(vs-vc))/0.87fy Assume ø mm2

Sv≤(Asv x 0.87fy)/(bv(vs-vc))

Page 42: Design Beam

42

Shear at L/4

= = 107 kN

= / bd = 2.06 N/mm²

Max Shear Stress = 1.39 N/mm²

= (0.79/1.25) [(100As/bd)^(1/3)] [(400/d)^(1/4)] [(fcu/25)^(1/3)]

= 1.09 N/mm²

+0.4= 1.49 N/mm²

» Vc+0.4 Vs < 0.8(fcu^(1/2))

8 mm » Area of link Asv= 101

» Link Spacin = 113 mm » 100 mm

Hence R8@100

» Existing Link Ø 8 mm @ 125 mm not enough

d -Check Deflection

=78.8 x

= 5.79200 x 68121

fs =5

fy =2

x 390 x1231

= 260 (Service Stress)8 3 1230.9

modification factor = 0.55 +477 - fs

= 0.9120

Bassic span/depth = 26 ( table3.9 in Code BS8110 Part 1 1985)

Allowable span/dep = 26 x 0.897 = 23.329

Actual span/depth = l /### = 6600 / 250 = 26.4 mm

» »Allowable span/depth= 23.33 <Actual span/depth= 26 » NO

Vmax qll/4 / 2

Vstress Vmax

0.8(fcu^(1/2))

Vcapacity

Vcapacity

Asv≥(bv Sv(vs-vc))/0.87fy Assume Ø mm2

Sv≤(Asv x 0.87fy)/(bv(vs-vc))

Mmax 106

bd2

As,req

As,pro

(0.9+(M / bd2))

Page 43: Design Beam

43

e -Check Cracking

Refer 3.12.11.2.3

1/ CLear distance between horizontal tension bars

Allowable clear distance between bars

= 155 (table 3.28)

=

= 51 mm < 155 OK

Clear Distance between the face of the beam and nearest longitudinal bar in tension

=

y =

= 41 mm

Allowable distance

= 155x0.5 = 77.5 mm

» = 50 mm < 77.5 bar should be provided in side faces of beam to control cracking

Distance between bars

Sb ≤ 250 mm

S1 (b-2(cover)-2(Ølinks)-2(Øbar))/2

S2 ((y2+y2)^(1/2))-(Øbar/2)

cover+Ølink+(Øbar/2)

S2

Page 44: Design Beam

44

Minimum size bar

Ø >

> 11.32 mm

Provide DB12 @ 250

((Sbb/fy)^(1/2))


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