Scaffold

DESIGN CALCULATION Structure:

Project: Compute. By

Date:

3-Nov-06

Checked By:

Design Criteria:

Pg 1

1. Slab Thickness (Case 1) 2. Beam Section b x d (Case 1)

200

x

310

mm

650

mm

3. Using Timber Keruing or equivalent group B timber Allowable flexure stress: 12.41 N/mm2 Allowable shear stress: 1.17 N/mm2 Modulus of elasticity: 11700.00 N/mm2 4. Plywood: Allowable bending stress: Modulus,E :

10.00 N/mm2 7000.00 N/mm2

5. Design of scaffold in accordance with CP 23 6. Designed live loadings: a. Live load(during concreting) = b. Self weight of formwork =

1.50 kN/m2 0.50 kN/m2

DESIGN CALCULATION Structure:

Project: Compute. By

SLAB DESIGN

3-Nov-06 Case 1: Slab thickness = 200mm Date:

Spacing of runners, s = Design loads: Concrete (wet) = Design load, F = Assume continuous span, with Modulus,Z = 24000.00 Mmax = 0.10 Max. shear force = 1.74 Check Bending: fbc = 4.12 Check Deflection: d= 0.83 i.e. Plywood is adequate

Checked By:

Pg 2

285 mm 7.75 kN/m2 9.75 kN/m2 12 mm thick plywood mm3 kNm kN N/mm2

< Limit:

10.00

ok!

mm

< Limit:

3.00

ok!

< Limit:

12.41

ok!

< Limit:

1.17

ok!

< Limit:

4.44

ok!

4.17 N/mm2

< Limit:

12.41

ok!

0.28 N/mm2

< Limit:

1.17

ok!

0.45 mm

< Limit:

3.00

ok!

Runners:(Section) 50 wide Span = 1.20 m Load/runner = 2.78 kN/m Modulus,Z = 83333.33 mm3 Mmax = 0.50 kNm Max. shear force = 2.08 kN Check Bending: fbc = 6.00 N/mm2 Check Shear: Shear Stress = 0.42 N/mm2 Check Deflection: d= 1.54 mm

100 deep

Check for the cantilever: Max. cantilever L = Load/runner = Mmax = Max. shear force = Check Bending: fbc = Check Shear: Shear Stress = Check Deflection: d=

0.50 2.78 0.35 1.39

m kN/m kNm kN

Beams:(Section) 100 wide Span = 0.85 m Load/runner = 4.17 kN Modulus,Z = 166666.67 mm3 Mmax = 1.67 kNm Max. shear force = 4.17 kN Reaction = 8.34 kN

100 deep

DESIGN CALCULATION Structure:

Project: Compute. By

Check Bending: fbc = Check Shear: Shear Stress = Check Deflection: d=

3-Nov-06

Date:

Checked By:

Pg 3 10.00 N/mm2

< Limit:

12.41

ok!

0.42 N/mm2

< Limit:

1.17

ok!

2.62 mm

< Limit:

3.15

ok!

BEAM DESIGN Beam width = 200 Spacing of runners, s = Design loads: Concrete (wet) = Design load, F = Assume continuous span, with Modulus,Z = 24000.00 Mmax = 0.09 Max. shear force = 2.28 Check Bending: fbc = 3.80 Check Deflection: d= 0.4 i.e. Plywood is adequate

Depth =

650 200 mm

16.25 kN/m2 18.25 kN/m2 12 mm plywood mm3 kNm kN N/mm2

< Limit:

10.00

ok!

mm

< Limit:

3.0

ok!

< Limit:

12.41

ok!


1.17

ok!

< Limit:

4.44

ok!

5.48 N/mm2

< Limit:

12.41

ok!

0.37 N/mm2

< Limit:

1.17

ok!

0.58 mm

< Limit:

3.00

ok!

Runners:(Section) 50 wide Span = 1.20 m Load/runner = 3.65 kN/m Modulus,Z = 83333.33 mm3 Mmax = 0.66 kNm Max. shear force = 2.74 kN Check Bending: fbc = 7.88 N/mm2 Check Shear: Shear Stress = 0.55 N/mm2 Check Deflection: d= 2.02 mm

100 deep

Check for the cantilever: Max. cantilever L = Load/runner = Mmax = Max. shear force = Check Bending: fbc = Check Shear: Shear Stress = Check Deflection: d=

0.50 3.65 0.46 1.83

m kN/m kNm kN

DESIGN CALCULATION Structure: 3-Nov-06 Checked By: 100 deep

Project: Compute. By

Date:

Beams:(Section) 150 Span = 1.20 Load/runner = 5.48 Modulus,Z = 250000.00 Mmax = 2.70 Max. shear force = 10.81 Check Bending: fbc = 10.79 Check Shear: Shear Stress = 0.72 Check Deflection: d= 1.34

wide m kN mm3 kNm kN

Pg 4

200 100

N/mm2

< Limit:

1200 12.41

ok!

N/mm2


1.17

ok!

mm

< Limit:

4.44

ok!

Check Load to Scaffold Leg Maximum load per leg, F =

16.29 kN

Allowable load per frame = 5 tonnes or 50 kN Allowable load per leg = 25 kN Therefore the scaffold is adequate provided the critical effective length of 1.8m is maintained by providing adequate ties/braces 1.2m

Use 50 x 100 timber at 1200 c/c to prop the formwork Allowable compression parallel to the grain :

8.62 N/mm2

Timber Prop 50 Span L= 0.34 Load/prop = 2nd moment of Area Iy=1041666.7 Radius of gyration ry = 14.4 Effective span Le = 0.3 Le / ry = 23.6

100 deep

wide m

4.17 kN mm3 mm3 m

As per CP23, table 3.7 For short term loads Limiting values of Le/r = 8.62E/ Cgpar = 108.2 > Modification factor K5=

1.46

Check compression: fc =

0.83 N/mm2

23.56

< Limit:

ok!

12.62

ok!