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STRUCTURAL DESIGN OF SINGLE CELL BOX CULVERT Based on AASHTO LRFD Bridge Design 2007 SI Client:

GeoData Survey Company

Designed By:

Job Name/Station:

Culvert Structural Design

Verified By:

Ali Akbar Shaikhzadeh

Date: Revision:

INPUT DATA 28 420 24 18 2940 3000 300 300 300 2000 0 144 30 16 75 2 150 150

CONCRETE COMPRESSIVE STRENGTH, f'c REBAR YIELD STRENGTH, fy CONCRETE UNIT WEIGHT, c SATURATED SOIL UNIT WEIGHT, s HEIGHT OFCULVERT, H WIDTH OF CULVERT, B THICKNESS OF SIDE WALLS, tw THICKNESS OF TOP SLAB, tts THICKNESS OF BOTTOM SLAB, tbs DEPTH OF FILL, hf IMPOSED SERVICE DEAD LOADS, wd ALLOWABLE SOIL PRESSURE, Qa SOIL ANGLE OF FRCITION,  PREFERRED REBAR SIZE CONCRETE COVER TO REBAR CENTER NO. OF REINFORCEMENT LAYERS MAIN REINFORCEMENT SPACING TEMPERATURE REINFOR. SPACING

MPA MPA kN/cum kN/cum mm mm mm mm mm mm KPa KPa Deg. mm

Design Summary

mm

Shear Status

O.K.

mm

Flexure Status

O.K.

mm

Soil Pressure Status

O.K.

mm

LL considered. Design Based on → Traffic travelling parallel to span

LOADS ON THE CULVERT For the design purposes a one-meter length of the culvert is considered.

Top Slab Vehicular Live Loads (HS 20 AASHTO Truck) Include live loads if hf < 2400mm Multiple presence factor Width of distributed load (parallel to span) Length of distributed load (perpend. to span) Pressure intensity at the specified depth of fill Linear load on the top slab

hf =

2000 1.20 2250 4510 7.14 7.14

mm mm KPa KN/m

Equiv. wheel loads don't overlap. Wheel Load = 72.5 KN Assumed to act on full width of the slab.

Dynamic Load Allowance (Impact Factor) IM = 33(1 - 0.00041 hf) > 0% Increased linear live load

5.94 9.08

% KN/m

Weight of earth fill Linear weight of fill on the slab

36.00

KN/m

0

KN/m

7.2

KN/m

Imposed dead loads Linear imposed dead loads on the slab Selfweight Linear selft weight of the slab

Side Walls Soil pressure kah = (1 - sin ) / (1 + sin ) Surcharge on side walls due to top soil

0.333 36.00

KPa

Factor for increasing live load due to impact effects Impact and multiple presence factor included.

Height of surcharge (h' = s / s )

2.00 29.6

Linear pressure at the bottom of the side wall

m kN/m

Selfweight Two side walls = tw (H - tbs - tts) c

33.70

KN

Bottom Slab Self weight of the whole structure Linear soil pressure due to stru. selfweight

61.632

kN/m

See note 1

9.08

KN/m

See note 1

Vehicular Live Loads (HS 20 AASHTO Truck) Linear soil pressure due to live loads

FACTORED LOAD DIAGRAMS 1.25 1.50 1.75

Load factor for dead load Load factor for horizontal earth pressure Load factor for live load 54.00 18.00

18.00

44.5

44.5

77.04

ANALYSIS OF THE STRUCTURE The structure is analyzed using the moment distribution method. The fixed-end moment at each joint is the superposition of the fixed-end moments due to dead, live and earth pressure loads.

A

Joint

B

D

C

Member

AC

AB

BA

BD

DB

DC

CD

CA

Length

2.34

3.00

3.00

2.34

2.34

3.00

3.00

2.34 0.0250

Moment of Inertia

0.0250

0.0250

0.0250

0.0250

0.0250

0.0250

0.0250

Distrib. Factor

0.56

0.44

0.44

0.56

0.56

0.44

0.44

0.56

FEM

13.04

-52.42

52.42

-13.04

15.46

-69.70

69.70

-15.46

Distribution

22.12

17.26

-17.26

-22.12

30.47

23.77

-23.77

-30.47

Carry Over

-15.24

-8.63

8.63

15.24

-11.06

-11.88

11.88

11.06

Distribution

13.41

10.46

-10.46

-13.41

12.89

10.06

-10.06

-12.89

Carry Over

-6.45

-5.23

5.23

6.45

-6.70

-5.03

5.03

6.70

Distribution

6.56

5.12

-5.12

-6.56

6.59

5.14

-5.14

-6.59

Carry Over

-3.30

-2.56

2.56

3.30

-3.28

-2.57

2.57

3.28

Distribution

3.29

2.56

-2.56

-3.29

3.29

2.56

-2.56

-3.29

Carry Over

-1.64

-1.28

1.28

1.64

-1.64

-1.28

1.28

1.64 -1.64

Distribution

1.64

1.28

-1.28

-1.64

1.64

1.28

-1.28

Carry Over

-0.82

-0.64

0.64

0.82

-0.82

-0.64

0.64

0.82

Distribution

0.82

0.64

-0.64

-0.82

0.82

0.64

-0.64

-0.82

Carry Over

-0.41

-0.32

0.32

0.41

-0.41

-0.32

0.32

0.41

Distribution

0.41

0.32

-0.32

-0.41

0.41

0.32

-0.32

-0.41

Moment Sum

33.44

-33.44

33.44

-33.44

47.65

-47.65

47.65

-47.65

Top Slab

45.19 -33.44

kN/m

45.19

kN/m

Top Slab Moment Diagram 50 40 30 20

kN/m

2.4

2.25

2.1

1.95

1.8

1.65

1.5

1.35

1.2

1.05

0.9

0.75

0.6

-10

0.45

0

0

Design Moment

0.3

10

0.15

Mmax (+) Mmax (-)

Mo m ent (kN-m )

SHEAR MOMENT DIAGRAMS

-20 -30 -40

kN

150 100 50

Design Shear

68.15

2.4

2.25

2.1

1.95

1.8

1.65

1.5

1.35

1.2

1.05

0.9

0.75

0.6

0.45

0

0.3

kN 0.15

104.84 -94.36

Top Slab Shear Diagram

0

Vmax (+) Vmax (-)

Shear (kN)

Distance x (m)

-50

kN

At distance d from the face of the support

-100 -150

Distance x (m)

40

2.4

2.25

2.1

1.95

1.8

1.65

1.5

1.2

1.35

-20

1.05

Design Moment

0.9

0

0

0.75

20

0.6

56.90

kN/m

kN/m

60

0.45

kN/m

0.3

47.65 -56.90

Bottom Slab Moment Diagram

0.15

Mmax (+) Mmax (-)

Mo m ent (kN-m )

Bottom Slab

-40 -60

100

At distance d from the face of the support

-100 -150 -200

Distance x (m)

2.4

2.25

2.1

1.95

1.8

1.65

1.5

1.2

1.35

-50

1.05

0

0

Design Shear

0.9

50 0.75

kN

150

0.6

90.61

kN

200

0.45

kN

Bottom Slab Shear Diagram

0.3

139.40 -139.40

Distance x (m)

0.15

Vmax (+) Vmax (-)

Shear (kN)

-80

Mmax (+) Mmax (-)

48.27 -17.02

Mo m ent (kN-m )

Side Walls

kN/m

Side Walls Moment Diagram 60 50 40 30

kN/m

20

1.755

1.872 1.872

1.638 1.638

1.755

1.521 1.521

1.404

1.287

1.17

1.053

0.936

0.819

0.702

0.585

0.468

0.351

0 -10

0.234

10

kN/m

0.117

48.27

0

Design Moment

-20 -30

Distance x (m)

Shear (kN)

Side Walls Shear Diagram

7.04 -44.98

1.404

1.287

1.17

1.053

0.936

0.819

0.702

0.585

0.468

0.351

-10

Vmax (+) Vmax (-)

0.234

0

0

0.117

10

kN -20

kN

-30

Design Shear

38.69

kN

-40

At distance d from the face of the support -50

Distance x (m)

THICKNESS CHECK Shear strength provided by concrete = Vc0.17 (f'c)0.5 bw d d (mm)

VckN)

Vd (kN)

Status

Top slab

225

151.8

68.1

O.K.

Bottom slab

225

151.8

90.6

O.K.

Side walls

225

151.8

38.7

O.K.

Component

REINF. CALCULATIONS Minimum reinforcement ratio for main reinforcement, ρmin

0.00078

See note 2

Minimum reinforcement ratio for temperature reinforcement, ρmin

0.00081

See note 2

Maximum center to center spacing of reinforcement, smax

450.00

Component

Max (1.5 t, 450)

mm

MAIN REINFORCEMENT

TEMPRATURE REINF.

d (mm)

Mu(kN-m)

As (mm )

As prov

ρact

ρmin

Status

ρact

ρmin

Top slab

225

50.2

590

2681

0.0089

0.0016

O.K.

0.0089

0.0016

Bottom slab

225

63.2

743

2681

0.0089

0.0016

O.K.

0.0089

0.0016

Side walls

225

53.6

631

2681

0.0089

0.0016

O.K.

0.0089

0.0016

2

SOIL PRESSURE CHECK Pressure on soil Allowable soil pressure Status

70.71 144.00 O.K.

KPa KPa

1- In reality, the uplift soil pressure on the bottom slab may not be uniform. However, for simplicity, it shall be assumed to be uniform. 2- Minimum reinforcement ratio found is for one layer of reinforcement and shall be multiplyed by 2 if there is 2 layers of reinforcement. 3- Clear distance between two layers of reinforcement shall not be more than 150mm and less than 25mm. 4- All soil has been assumed to be saturated soil. 5- It has been assumed that only one axle of the design truck comes on the culvert at a time. This is true for culvert width up to 4300. For more widths this design spreadsheet can not be used since it is possible that two axle loads come on the culvert.

N OF SINGLE CELL BOX CULVERT

TO LRFD Bridge Design 2007 SI Hanz 11158 11/2/2016 2:03 Version 1.0

(AASHTO 3.6.1.2.6) (AASHTO 3.6.1.1.2) (AASHTO 3.6.1.2.6) (AASHTO 3.6.1.2.6)

(AASHTO 3.6.2.2)

Factor for increasing live load due to impact effects

(cont'd)

(AASHTO 3.4.1) (AASHTO 3.4.1) (AASHTO 3.4.1)

15.89

15.89

Distance x (m)

3

2.85

2.7

2.55

2.4

2.25

2.1

1.95

1.8

1.65

1.5

1.35

1.2

1.05

0.9

0.75

0.6

0.45

3

2.85

2.7

2.55

2.4

2.25

2.1

1.95

1.8

1.65

1.5

1.35

1.2

1.05

0.9

0.75

0.6

0.45

3

2.85

2.7

2.55

2.4

2.25

2.1

1.95

1.8

1.65

1.5

1.35

1.2

1.05

0.9

0.75

0.6

0.45

3

2.85

2.7

2.55

2.4

2.25

2.1

1.95

1.8

1.65

1.5

1.35

1.2

1.05

0.9

0.75

0.6

0.45

(cont'd)

Top Slab Moment Diagram

Distance x (m)

Top Slab Shear Diagram

Distance x (m)

Bottom Slab Moment Diagram

Distance x (m)

Bottom Slab Shear Diagram

(cont'd)

1.404

1.521

1.638

1.755

1.872

1.989

2.106

2.223

2.34

1.404

1.521

1.638

1.755

1.872

1.989

2.106

2.223

2.34

1.287

1.17

1.053

0.936

0.819

0.702

0.585

0.468

0.351

Side Walls Moment Diagram

Distance x (m)

1.287

1.17

1.053

0.936

0.819

0.702

0.585

0.468

0.351

Side Walls Shear Diagram

Distance x (m)

(ACI 11.2.1.2)

(AASHTO 5.10.8) (AASHTO 5.10.8) (AASHTO 5.10.3.2)

TEMPRATURE REINF. Status

O.K. O.K. O.K.

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