pipe support columns at bridge crossing

8/10/2019 Pipe Support Columns at Bridge Crossing

1/9

1.0 DESIGN INFORMATION

1.1 Material Properties

Density of Concrete 24 kN/m3

Density of Water 9.81 kN/m3

Concrete Grade 30 N/mm2

Characteristic Strength of high yield Steel 460 N/mm2

Characteristic Strength of Mild Steel 250 N/mm2

1.2 Durability Requirement

Exposure Condition -Severe

Clear cover to r/f 50 mm

1.3 Foundation

Assumed bearing capacity 125 kN/mm2

Soil parameters c= 0 kN/mm2

(cohesionless soil) j= 300

g= 20 kN/m3

(Where c is cohesion,jis friction angle and gis the density.)

2.0 REFERENCES

BS 8110 Part 1 (1985)

British Standard Structural Use of Concrete

BS 8007 (1987)

Design of concrete structures for retaining aqueous liquids

BS 4466 (1981)

Reinforced Concrete Designers Hand Book

R.E.Renolds and James C. Steedman - 10 th Edition

Standard Method of Detailing Structural Concrete

By Institution of Structural Engineers UK

Specification for Bending Dimensions and Scheduling of Reinforcement for Concrete.


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Design Data and Parameters

Material Properties

Density of Concrete kN/m3

Density of Water kN/m3

Concrete Grade N/mm2

Characteristic Strength of high yield Steel N/mm2

Durability Requirement

Exposure Condition - Severe

Clear cover to r/f mm

Foundation

Bearing capacity (assumed) kN/m2

Soil parameters c= kN/m2

j=

g= kN/m3

(Where c is cohesion,jis friction angle and gis the density.)

460

50

100

5

18

10

OutputCalculations

30 0

1.0

24

25

Reference


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OutputCalculationsReference

Design of the Column Support (Intermediate)

Height of the support = m

Pipe diameter = m

Length of a pipe = m

Self wt of pipe (One pipe length) = kN

Column size = m

Clear height = m

End condition at top =

End condition at bottom =

=

Effective height (Lexor Ley) =

Lex/h or Ley/b =

> 15

The column is slender

Minimum eccentricity = mm

2.1 Load Calculation

Wt of water inside = kN

Self wt of the column = kN

Additional imposed load (0.5kN/m) = kN

Impact force at top = kN

Moment at the base due to impact force = kNm

Moment due to eccentricity = kNm

0.35

0.30

4.00

3.05

1

25.14

2.2

2.0

6.00

4.00

4

11.76

6.10

24.40

8.80

0.65

3.00

20

4.24

Assume an impact load due to pipe hitting at

top at 2.0m/s during handling

Assume that the pipe will not be submerged. The maximum flood

level is about 2000 above the ground level. The pipe is placed

500mm above the maximum flood level. Each pipe is supported by

a concrete column. Foundation of each column will be placed at a

depth of 1500 below the ground.

Cl.3.8 BS

8110 P-1

200 DI Pipe

Column

Max.water level

GL h Max.=3500mm

6000

Min.500mm

1500mm

300DI Pipe

Min 500mm

hmax= 4000mm

6000 mm

Column

1500mm


4/9


Water pressure inside the pipe = bars

= kN

Moment at base due to the bend at top = kNm

Assume a log impact during flood

Weight of log assumed = Tons

Velocity of flood (assumed) = m/s

Force at top of column due to log impact =

= kN

Moment acting on the column base = kNm

Total axial load during construction (Ult) = kNm

(Self wt of pipe+column+Imposed load)

Total moment during construction (Ult) = kNm

(Due to eccentricity+Impact force)

Total axial load during functioning (Ult) = kNm

(Self wt of pipe+column+Imposed load+water load)

Total moment during functioning (Ult) = kNm

(Due to eccentricity+pipe pressure+Log impact)

2.2 Design of the column

Cover = mm

b = mm

h = mm

Vertical r/f bar diameter = mm

Stirrups = mm

d = mm

k =

Z = mm

Zcorrect = mm

As = mm

Provide 4 T 16 + As = mm2

(Per face)

Design of Stirrups

Stirrups size = 6mm or

(1/4)*vertical bar dia

= mm

Spacing = 12xBar dia

= mm

Use stirrups as R-06 @ 175

25.53

6.00

24.00

50

39.95

32.32

74.85

242.87

242.87

770.1

805

350

16

282

0.108

350

2.00

3.00

0.1*W*v

15

5.55

Column is subjected to very low axial load. Therefore it can be

designed as a cantilever beam.

10

Assume that the pipe line it straight and no bends. Force due to

water pressure due to 30rotation at top

22.21

4.0

192


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Check for minimum area of r/f

sc c =

sc = mm2

Satisfactory

2.3 Design of the base

Total axial load during construction (Ser) = kNTotal moment during construction (Ser) = kNm

Total axial load during functioning (Ser) = kN

Total moment during functioning (Ser) = kNm

Max axial force at the base (Service) = kN

Max moment at the base (Service) = kN

Assumed bearing capacity = kN/m2

Assumed "B" = m

Assumed"L" m

assumed "h" = m

Pressure under the base (SLS) = kN/m2

Pressure under the base (ULS) = kN/m2

Hence ok.

Design for moment

Maximum moment at base = kNm

Assume r/f bar diameter = mm

dmin = mm

dmax = mm

davg = mm

k =

Z = mm

Zcorrected = mm

As required = mm2

Provide T 10 - As = mm2/m

Design for Shear

Shear force at a distance d = kNShear stress = N/mm

ear capac ty vc = N/mm2

Vertical line shear is not critical

Consider the shear perimeter at 1.5d

Shear stress = N/mm

Punching shear is not critical

100.00

190

518

0.027

116.56

36.42

185

195

179.4

1.600

83.26

0.250

46.86

37.41

1.600

Cl.3.11 BS8110 P-1

0.50

10

175.8

150 524

46.86

33.1725.05

37.41

0.29

Table 3-27

BS 8110 P-1

0.4

490.0

82.060.28


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Design of the Column Support (At the End)

Height of the support = m

Pipe diameter = m

Length of a pipe = m

Self wt of pipe (One pipe length) = kN

Column size = m

Clear height = m

End condition at top =

End condition at bottom =

=

Effective height (Lexor Ley) =

Lex/h or Ley/b =

> 15

The column is slender

Minimum eccentricity = mm

2.1 Load Calculation

Wt of water inside = kN

Self wt of the column = kN

Additional imposed load (0.5kN/m) = kN

Impact force at top = kN

Moment at the base due to impact force = kNm

Moment due to eccentricity = kNm

Water pressure inside the pipe = bars

The pipe line has a 450downward bend

Force due to the bend (perpendicular ) = kN

= 2*P*A*Sin(/2)

Horizontal component of the force = kN

Moment at base = kNm

Assume a log impact during flood

Weight of log = TonsVelocity of flood (assumed) = m/s

Force at top of column due to log impact =

= kN

Moment acting on the column base = kNm

Total axial load during construction (Ult) = kNm

(Self wt of pipe+column+Imposed load)

Cl.3.8 BS

8110 P-1 0.30

6.00

4.00

4.00

3.05

0.35

3.00

0.1*W*v

6.00

2.00

24.00

25.53

6.10

Assume an impact load due to pipe hitting at

top at 2.0m/s during handling

11.76

3.00

229.62

15

81.18

24.38

0.65

57.41

4.24

1

8.80

25.14

20

2.2

4

3.0


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Total moment during construction (Ult) = kNm

(Due to eccentricity+Impact force)

Total axial load during functioning (Ult) = kNm

(Self wt of pipe+column+Imposed load+water load)

Total moment during functioning (Ult) = kNm

(Due to eccentricity+pipe pressure)

2.2 Design of the column

Cover = mm

b = mm

h = mm

Vertical r/f bar diameter = mm

Stirrups = mm

d = mm

k =Z = mm

Zcorrect = mm

As = mm

Provide 4 T 25 + As = mm2

(Per face)

Design of Stirrups

Stirrups size = 6mm or

(1/4)*vertical bar dia

= mmSpacing = 12xBar dia

= mm

Use stirrups as T10 @300

Check for minimum area of r/f

sc c =

sc = mm2

Satisfactory

2.3 Design of the base

Total axial load during construction (Ser) = kN

Total moment during construction (Ser) = kNm

Total axial load during functioning (Ser) = kN

Total moment during functioning (Ser) = kNm

Max axial force at the base (Service) = kN

Max moment at the base (Service) = kN

Assumed bearing capacity = kN/m2

Assumed "B" = m

Assumed "H" = m2.650

254.27

100.00

2.650

1964

10.0

300

76.80

81.04

81.04

25.03

254.27

Cl.3.11 BS

8110 P-1

1440.0Table 3-27

BS 8110 P-1

0.4

600

32.32

Column is subjected to very low axial load. Therefore it can be

designed as a cantilever beam.

483.93

483.93

1901.7

25

10

527.5

0.068

368.30

600

50

39.92


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assumed "h" = mm

Pressure under the base (SLS) = kN/m2

Pressure under the base (ULS) = kN/m2

Hence ok.

Design for moment

Maximum moment at base = kNm

Assume r/f bar diameter = mm

dmin = mm

dmax = mm

davg = mm

k =

Z = mm

Zcorrected = mm

As required = mm2

Provide T 16 - As = mm2/m

Design for Shear

Shear force at a distance d = kN

Shear stress = N/mm

ear capac ty vc =

Vertical line shear is not critical

Consider the shear perimeter at 1.5d

Shear stress = N/mm2

Punching shear is not critical

182.26

93.52

130.93

110 1829

259.87

0.350

0.36

0.036

264.4

262.2

1737

16

276

292

284

N/mm20.60

0.39


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Check the Column head

Total axial load (Ult) = kN

(Pipe wt+Water wt+Imposed Load)

Plan area = mm2

Stress on the column head = N/mm2

Stress that can be resisted by concrete = N/mm

Hence Satisfactory

0.137

10

4.0

10.29

75250

215

350

150 150

200

100

pipe support columns at bridge crossing

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