Beams Designs

8/10/2019 Beams Designs

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DESIGN OF SIMPLY SUPPORTED BEAM

1 INPUT DATASINPUT Length of Beam L 5.0 Mtr

INPUT Width of Beam B 0.25 MtrINPUT Grade of Concrete M 25

INPUT Grade of Steel Fe 415

Type of Support of Beam SS

= 20 for CAN/SS/CON '7/20/26

=1 1 =1 up to 10 m, L>10, L/10

= 0.9 CAL VALUE =Factor % Tension Rft =1 for 1 %,

= 1 =Factor of Compression Rft 1 for

= 1 = Factor of Flanged Beam 1 for we

Span / Eff depth Ratio 18

Min Effective Depth of Beam = 120 mm

INPUT Adopt Overall Depth of Beam D 0.45 Mtr

Effective Length of Beam Le 5.12 Mtr

Width of Beam B 0.25 Mtr

2 CALCULATION OF LOAD, BM & SF

Dead Load of Beam 2900 N/m

INPUT Super Imposed Dead Load 15000 N/m

INPUT Super Imposed Live Load 12000 N/mTotal DL + LL 29900 N/m

Load Factor 1.5

Factored Load w 44850 N/m

Length of Beam L 5.00 Mtr

Max BM at the Mid Span Mu= w L^2/8 140.16 KN m

Max SF at Support Vu= 1/2 w Lx 112.13 KN

Length of Beam L 5.00 Mtr

Max BM at the Mid Span Mu= w L^2/8 140.16 KN mMax SF at Support Vu= 1/2 w Lx 112.13 KN

3 DESIGN OF MEMBER TO RESIST BENDING MOMENT

Grade of Concrete M 25

Grade of Steel Fe 415

Width of Beam 0.3 Mtr Max Depth of Nutral Axi

CAN/SS/CON '7/20/26


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Max BM Mx 140.16 KN-M fy Xm=0.0035/

BM = (Const*fck) bd^2 3.444 bd^2 250 0.53

Calculated Eff Depth of Beam 403 mm 120 415 0.48

RESULTAdopt Effective Depth d 410 mm 500 0.46

INPUT Use Dia of Main rft 20 mm

Adopt Cover for Beam 30 mm Limiting Moment of resiRESULT Over all Depth of Beam D 450 mm Const= 0.36

Width of Beam 250 mm

Grade of Concrete M 25 Concrete Fe 250

Grade of Steel Fe 415 15 2.229

a= 0.87 *(fy^2/fck) 5993.43 20 2.972

b= -0.87 fy -361.05 25 3.715

c= m= Mu/(bd^2) m= Mu/(bd^2) 30 4.458

35 5.201

m= Mu/(bd^2) p %= (-b- sqrt(b^2-4ac))/2a At

3.34 1.139 1168 Sqmm

Min area of Tension Steel Ao=0.85*bd/fy 209.94 Sqmm

Max area of Tensile Steel = 0.04 bD 4500 Sqmm

Provide Area of Tension Steel 1168 Sqmm

Area of One Bar 314.29 Sqmm 20 mm Dia

RESULT No of Bars 4 Nos 20 mm Dia

4 DESIGN/ CHECK FOR MEMBER TO RESIST SHEAR


Effective Depth of Beam 410 mm

Over all Depth of Beam 450 mm Grade of Concrete M

Width of Beam 250 mm Max SS N/Sqmm

Dia of Main rft 20 mm fck

Area of One Bar 314.29 Sqmm Design

No of Bars 4 Nos 100 As bd

Max Shear Force wl/2 112.13 KN 1.14

Percentage of Tensile Steel 100At/2bd = 1.14 %

Grade of Concrete M

Design Shear Strength 0.673 N/ Sqmm Max SS N/Sqmm

Calculated k Value 1.00

INPUT For 450 mm thick slab, k= 1.00 Ds


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k

Permissible Max Shear Stress 0.673 N/ Sqmm

* Shear rft

Nominal Shear stress Vu/bd 1.09 N/ Sqmm

Maximum Shear stress Tcm 3.10 N/ Sqmm

Shear Check Un safe

Design of Stirrups


Grade of Steel Fe 415

Effective Depth of Beam 410 mm

Over all Depth of Beam 450 mm

Width of Beam 250 mm

Dia of Torsion rft 20 mm

Area of One Bar 314.29 Sqmm

Adopt Cover for Side Rft 30 mm

Max Shear Force Vu 112.13 KN

Strength of Shear rft Vus=Vu-Tc bd 43134 N

INPUT Dia of Shear rft 10 mm


INPUT No of legged vertical stirrups 2 Nos

Area of Vertical Stirrup Rft Asv 157.14 mm

RESULT Spacing of Shear rft x=0.87 fy Asv d/ V 540 mm 307.5 10 mm DiaCheck for Spacing OK Min Spacing is 100 mm for placing

Min Area of Shear rft 0.4 b x /fy 74 Sqmm

Check for Shear rft Area OK If NOT OK then Increase the size of

5 CKECK FOR DEVELOPMENT LENGTH

Max Shear Force wl/2 112.13 KN Design Bond Stress

Grade of Concrete M 25 Greade 15 20

Grade of Steel Fe 415 Tbd N/Sqmm 1.0 1.2

Adopt Effective Depth d 410 mm

Width of Beam b 250 mmDia of Main rft 20 mm

Area of Tension rft 1168 Sqmm


No of Bars 4 mm

Assumed Development Length 200 mm

INPUT Bond Stress Tbd 2.2 N/Sqmm


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Development Length based on Anchorage Bond

Ld= 0'0.87 fy / 4Tbd

Ld in Anchorage Bond 806 mm

Development Length based on Flexural Bond

Ld= 1.3 M1/V + Lo

INPUT Assumed Development Length 220 mm

Moment of Resistance offered by 20 mm dia bar @ 8

M1 = 140,194,000 Nmm

V = 112125 N Development Length

Ld in Flexural Bond 1845 mm fy N/Sqmm

Factor of Develop Length 56 M15 M20

Develop length of Single Bar 1120 mm 250 55 46

415 56 47

Max Development Length 1845 mm 500 69 58

Max Bar Size in Develop Length 46 mm

Check for Development Length OK If NOT OKThen increase No of Bar

6 CHECK FOR DEFLECTION

Short Span of Slab 5.0 Mtr

Effective Depth d 410 mm

Width of Beam b 250 mm

Dia of Slab rft 20 mm

Area of Tension rft 1168 Sqmm

Area of One Bar 314 Sqmm

Spacing of Bars 270 mm

Percentage of tension steel at Mid Span = 1.14 %

= 26 for CAN/SS/CON '7/20/26

=1 1 =1 up to 10 m, L>10, L/10

INPUT Cal = 0.92 = 0.9 =Factor % Tension Rft =1 for 1 %,

= 1 =Factor of Compression Rft 1 for

= 1 = Factor of Flanged Beam 1 for we

Allowable L/d 23.4

Actual L/d 12.20

Deflection Check is OK

Tension Bars


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Fig 10.1

0 % Fig 10.2

b L=B Fig 10.3

s


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(.0055+0.87*fy/Es), Es= 200000 N/Sqmm

d

d

d

tance MR = Const * b*d^2 N mm*fck*Xm(1-0.42*Xm)

Fe 415 Fe 500

2.067 1.991

2.755 2.655

3.444 3.318

4.133 3.982

4.822 4.645

Max Shear Stress

25

3.1

25

Shear Strength

SS N/Sqmm

2.55 0.673

Max Shear Stress

15 20 25 30 35

2.5 2.8 3.1 3.5 3.7

Value of K

>300 275 250 225 200 175


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1.00 1.05 1.10 1.15 1.20 1.25 1.30

e provided in a slab deeper than 200 mm

2 Legsf Concrete, Max 450 mm

Rft oa more No of Legs

25 30 35 40

1.4 1.5 1.7 1.9


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Nos

or Single Bars

M15 M20

44 37

45 38

54 46

s

Fig 10.1

0 % Fig 10.2

b L=B Fig 10.3

Compression Bars


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Beams Designs