Precast Plank Design

 

 PJPT Project :  RSKU Kundang

 

Date :

Subject :  4.2m Long Precast Plank 

 

Calculations

Ref 

Remarks

Material Parameters:

Grade of Concrete =

2

gc =

1.5

2

gs =

1.15 1.4

30 N/mm 500 N/mm

Grade of Steel

=

Concrete cover ,

c=

25 mm

gf D.L =

Thickness of Plank = Thickness of Topping =  Spacing of Lattice Girder =

65 mm 75 mm 600 mm

gf L.L =

Thickness of Slab, t =

1.6 140 mm

2

250 N/mm

Grade of Steel Steel Shear = Loadings:

Finishes :

0 kN/m

2

Others :

0 kN/m

2

M&E:

0.3 kN/m

2

Imposed Load :

2.5 kN/m

2

S.D.L

L.L

Design: Case : 1

Lifting case Dynamic Factor for Lifitng =

1.5 2

Self Wt of Plank =

1.56 kN/m

Factored Self Wt =

2.34 kN/m

2

From Analysis, Refer Appendix 1 Moment Top

MTOP =

2.2 kNm

Moment Bottom

Mbottom =

1.5 kNm

Diameter of Lattice Top bar, φt =

10 mm

Diameter of Lattice bottom bar, φ b =

6 mm

Diameter of Slab Top bar, φ ts =

8 mm

Diameter of Slab bottom bar, φbs =

10 mm

Diameter of Slab distribution bar, φ bds =

8 mm

Diameter of Diagonal bar, φds =

Lever arm of Lattice Girder, Z =

6 mm 48 m m

Ast TOP Lattice Girder =

63.25 mm

2

Ast bottom Lattice Girder =

43.125 mm

2

Shear,V = Force in Diagonal bar=

3.5 kN 2.97 2.97 kN

Ast Shear Area Girder = Area of diagonal Lattice bar=  per interface area cross section

Use T10 bar Use T6 bar

( inclined at 45 degree) 10.3 mm

2

USE

0.28 Use R6 bar

Summary : 10 m m 6 mm 6 mm

Lattice Girder top bar = Lattice Girder bottom bar = Lattice Diagonal bar = Case : 2

Final Case 3.36 kN/m

2

SDL =

0.3 kN/m

2

IL=

2.5 kN/m

2

9.12 kN/m

2

Self Wt of Slab =

Factored Design Load = Effective Depth of Slab = Lever arm of slab = Span =

4/5/2017 

Done by :  Alex 

110 110.00 .00 mm 104.50 mm 4200.00 mm

From Analysis, Refer Appendix 2

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6 bar size

 

 PJPT Project :  RSKU Kundang

 

Date :

 

Subject :  4.2m Long Precast Plank 

Ref 

4/5/2017 

Done by :  Alex 

Calculations

Remarks

Moment Top

MTOP =

20.1 kNm

Moment Bottom

Mbottom =

14.9 kNm 2

Ast TOP First Internal Support =

365.00 mm /m

Ast BOTTOM End Span =

275.00 mm /m

2

Spacing=

100

Spacing=

100

2

Ast Provided Top= Ast Provided Bottom=

505.00 mm /m 2 785.00 mm /m

Ast Minimum=

182.00 mm /m

   

2

Spacing=

200

Deflection Check: Tension Modification factor =

1.96

Basic Value=

20

Allowable Deflection= Actual Deflection=

39.2 38.18

Deflection Pass

Summary : Provide Top Steel T8@100 @ Support Provide Bottom Steel T10@100 @ Mid Span Provide Distribution steel T8@200 Case : 3

Construction stage

2

Number of Props=

2

Self Wt of Plank =

1.56 kN/m

Self Wt of Topping =

1.875 kN/m

Total Dead Load =

3.435 kN/m

Construction load =

1.5 kN/m

2 2 2

From Analysis, Refer Appendix 3 Moment Top

MTOP =

1.4 kNm

Moment Bottom

Mbottom =

1.3 kNm

Ast TOP First Internal Support =

2

45.00 mm /m 2

Ast BOTTOM End Span =

40.00 mm /m

Ast Provided Top=

78.50 mm /m

Ast Provided Bottom=

2

2

815.00 mm /m

Result :

Length of Plank= 4.2m Number of propping propping = 2 Lattice Girder Top bar = T10 bar. Lattice Girder Bottom bar = 2T6 bar. Lattice Diagonal bar =R6 bar. Provide Bottom Steel Reinforcement T10 - 100C/C. Provide Top Steel Reinforcement T8 - 100C/C. Provide Distribution Reinforcement T8 - 200C/C.

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