MANAR AL OMRAN CO SCAFFOLDING & FORMWORK TECHNOLOGY

PROJECT : OLGANA TOWER (2B+G+3P+38+Roof)

CLIENT : Delta Emirates Contracting Co LLC

SUBJECT : DESIGN CALCULATION FOR SLAB

SUPPORT SCAFFOLDING

CALCULATED B Y : ENG NASEER

CHECKED BY: ENG. SHAHID

Max thickness of Slab = 40 cm

System Used: Cuplock with Aluminum

Maximum grid size adopted= 1.6 m x 1.2 m

FORMWORK MATERIAL TECHNICAL DATA

Plywood: Allowable Bending stress Fb = 8.27 N/m

2 Allowable shear stress Fv = 0.365 N/ m

2 Modulus of Elasticity E = 8273.76 N/ m2

Aluminum Beam:

Allowable Bending Moment on Aluminum = 8.75 KNM

Allowable Shear Force = 45.11 KN

Vertical Standard :

Safe working Load = 35 KN

DESIGN CALCULATIONS

1) PLYWOOD:

DESIGN OF PLYWOOD SHEATING:

Considering Plywood Strip = 10cm under slab Width of plywood strip = 0.10m Span of plywood (B/w Secondary beam) = 400mm

Technical Data of Plywood: Allowable Bending stress Fb = 8.27 N/M 2 Allowable shear stress Fv = 0.365 N/M 2 Modulus of Elasticity E = 8273.76 N/M 2

Loading Intensity 0.10 KN/M run: Self weight of the Slab = 0.40*25*0.10 (width of strip) = 1 KN/M Live Load = 2.40*0.10 = 0.24 KN/M Wt of plywood = 0.105*0.10 = 0.0105 KN/M Total Weight = 1.2505 KN/M

Check through Bending Stress-Shear & Allowable Deflection Max. Bending Moment BM = WL2 = 1.2505*0.40*0.40 = 0.02 KN-M

10 10

Max. Shear Force V = 0.50WL = 0.50*1.2505*0.40 = 0.25 KN

Allowable Deflection = L/360 = 400/360 = 1.11mm For 0.10m strip * 18mm thick of Plywood Section modulus Z =bd

2/6 =100(18)

2/6 = 5400mm3

Moment of Inertia Ixx =bd3/12 =100(18)

3/12 = 48600mm3

Moment Area about N/A axis Q =100*9*9/2 = 4050mm3 Width of plywood strip B = 100mm

Bending Stress Fbr = M = 0.02*1000*1000 = 3.70 N/mm

2 Z 5400 3.70 < 8.27 N/mm2 ------------------------------- (SAFE) Shear stress Fvr = VQ = 0.25*1000*4050 = 0.208 N/mm

2 IxxB 48600*100 0.208 < 0.365 N/mm2 --------------------------------- (SAFE)

Max. Deflection max WL4 = 1.2505*(400)

4 = 0.62 mm 128EI 128*8273.76*48.600 0.62 < 1.11 mm ----------------------------------------- (SAFE)

Calculation of loading intensity

Self Weight of the Slab = 0.4 x 25 = 10 KN/M2

Weight of the formwork = 0.5 KN/M2

Live Load = 2.4 KN/M2 TOTAL w = 12.9 KN/M2

2) SECONDARY BEAM:

UDL on secondary beam W = spacing x w

= 0.4 x 12.9

= 5.16 KN/M

W = 5.16 KN/M, L=1.6 M

Maximum Bending Moment= (W x L2)/8 = (5.16 x 1.62)/8 = 1.65 KNM

1.65 < 8.75 KNM ( SAFE )

Maximum Shear Force = ( W x L )/2 = ( 5.16 x 1.6 ) /2 = 4.12 KN

4.12 KN < 45.11 KN (SAFE)

Maximum Deflection max = 5WL4 = 5*5.16*(1600)

4 = 1.44 mm

384EI 384*70000*4581604

Allowable deflection= 1600/360 =4.44 mm 1.44 < 4.44 mm (SAFE)

3) PRIMARY BEAM:

Total UDL on Primary Beam = 1.6 x 12.9 = 20.64 KN/M

W=20.64 KN/M, L=1.2 M

Maximum Bending Moment= (W x L2)/8 = (20.64 x 1.22)/8 = 3.71 KNM

3.71 < 8.75 KNM (SAFE)

Maximum Shear Force = ( W x L )/2 = ( 20.64 x 1.2 ) /2 = 12.38 KN

12.38 < 45.11 KN (SAFE)

Maximum Deflection max = 5WL4 = 5*20.64*(1200)

4 = 1.83 mm

384EI 384*70000*4581604

Allowable deflection= 1200/360 =3.33 mm 1.83 < 3.33 mm (SAFE)

4) Vertical Standard:

Loading intensity = 12.9 KN/M2

Maximum Grid size = 1.6 x 1.2 m

LOAD ON ONE STANDARD = 12.9 x 1.6 x 1.2

= 24.76 KN

Allowable load on one Standard = 35 KN

24.76 < 35 KN (SAFE)