Manual Beam Design

BEAM DESIGN

1.DATA

L=3000mm

Dead load=6KN/m

Live Load=8KN/m

Finished load=0.75KN/m

Wall Support=230Mm

Concrete grade=M20, Steel grade=fe415

2.EFFECTIVE SPAN OF BEAM:

Effective Span =c/c of support

= 3230 mm

3.SIZE OF BEAM:

Effective depth=Span/12

=269.16mm , Say 270mm

Breadth=1/2d =135mm

Clear cover=25mm,Use 16 mm ø

D=303 mm, Say 310 mm

D=310mm

d = 277mm, Say 280mm

d=280mm

4.LOAD CALCULATIONS:

Self Weight =1× 0.31× 0.135× 25=1.046KN/m

Live Load = 8KN/m

Dead Load =6KN/m

Finished load =0.75KN/m

T0tal Load =15.796KN/m

Factored Load =23.694KN/m, Factored BM=Wl2/8 = 30.89KN/m

5.TO GET AST:

Ast(Required) = 388.33mm2

Numbers of rods = 2nos

Provide 2nos of 16mmø rods

6.CHECK FOR MINIMUM & MAXIMUM AST:

ASTmin=(0.85/Fy) bd =77.421mm2

ASTmax=0.04 bd=1512mm2

7.CHECK FOR SHEAR:

Nominal shear stress < permissible shear stress

ڂv =K ڂc ڂ & v=Vu/bd

Vu=38.26KN , ڂv=1.012N/mm2

Permissible shear stress (K ڂc)

100Ast/bd=1.026N/mm2

Refer From Table 19 for I.S. 456

ڂc = 0.625, ڂcmax=2.8 N/mm2

ڂ v > ڂc > ڂcmax

K ڂc=1×0.625=0.652N/mm2

8.SHEAR REINFORCEMENT:

Vus =Vu – ڂcbd

Vus =14.625× 103 N

Provided 8mmø rods @ 2 legged Stirrups

1) Sv= ( 0.87 Fy Asv d/ Vus)

=694.41mm, Say 690 mm

2) Sv= ( 0.8 7 Fy Asv / bd)

=96.01mm < Say 100mm

3) 0.75 d= 210mm

4) 450mm

Provide 8mmø rods & 2 Legged Stirrups @ 100mm c/c

9.CHECK FOR DEFLECTION:

FS=O.58 fy

Fs=240.7N/mm2 [M.F=2, BV=20]

Effective depth=Span/(BV×MF)

=80.75mm

80.75mm < 280mm

Hence it is safe

from: www.onlinecivilforum.com