Design Manual Tabulating Guardrail - Iowa … · Page 1 of 9 . Tabulating guardrail can be confusing because the tabulations are set up to handle many different situations. Because

Page 1 of 9

Tabulating guardrail can be confusing because the tabulations are set up to handle many different situations. Because of this, some columns are used in some situations but not used in other situations. Tabulating guardrail consistently makes it easier for contractors and inspectors to understand the designer’s intent and helps ensure that the guardrail is installed correctly.

The examples on the following pages illustrate how to tabulate guardrail for some common situations.

• Example 1: Steel Beam Guardrail at a Two-lane, Two-way Bridge (BA-250)

• Example 2: Steel Beam Guardrail at a One-way Bridge (BA-250)

• Example 3: Steel Beam Guardrail over a Low-fill Culvert (BA-250)

• Example 4: Side Obstacle Shielded with Steel Beam Guardrail (Two-way Protection) (BA-251)

• Example 5: Side Obstacle Shielded with Steel Beam Guardrail (One-way Protection) (BA-252)

• Example 6: Median Obstacle Shielded with High-tension Cable Guardrail (BA-351)

• Example 7: High-tension Cable Guardrail Attached to Steel Beam Guardrail (Case 1) (BA-250 and BA-351)

• Example 8: High-tension Cable Guardrail Attached to Steel Beam Guardrail (Case 2) (BA-250 and BA-351)

The column labeled Direction of Traffic in the tabulations simply indicates on which side of the highway the installation is located. The column labeled Side is used only with multilane divided highways to further clarify where the installation is located. Either M for ‘median’ or O for ‘outside’ is entered in this column.

Tabulating Guardrail

8B-10

Design Manual Chapter 8 Safety Design Originally Issued: 02-26-99

Revised: 04-29-11

Iowa Department of Transportation Office of Design

399+00

400+00

401+00

402+00

VT

1=

28

.1

WB

Lane

EB

Lan

e

Bid

Ite

ms

Lay

ou

t L

en

gth

s

BA

-202

BA-205

BA-200=75.0

VF=75.0

ET=50.0

Offset=

15

.8’

BA

-201

Sta

40

0+

00

.00

Sta

40

0+

05

.00

Sta

40

0+

49

.00

Sta

40

0+

44

.00

Chapter 8—Safety Design Section 8B-10—Tabulating Guardrail

Page 2 of 9

Example 1—Steel Beam Guardrail at a Two-lane, Two-way Bridge

VT

1=

28

.1VF=25.0

BA

-202

ET=50.0

EB

Lan

e

EB

Lan

e

Bid

Ite

ms

Lay

ou

t L

en

gth

s

VT

2=

137.5

198+00

199+00

200+00

Offset=

66

.8’

Offset=

25

.2’

BA

-201

BA

-205

BA

-2

00

=1

62

.5

Sta

19

9+

56

.09

Sta

19

9+

74

.75

Chapter 8—Safety Design Section 8B-10—Tabulating Guardrail

Page 3 of 9

Example 2—Steel Beam Guardrail at a One-way Bridge

Bid

Ite

ms

Lay

ou

t L

en

gth

s

D0=

12.0

’

Offset=

24

.0’

EB

Lan

e

WB

Lane

VT

1 =

43.8

AET=50.0

VT

1 =

25.0

TET=50.0

10+00

9+00

11+00

BA

-210 B

A-200=

62.5

BA-205

BA-205

Sta

10+

18.8

0

Sta

9+

81.2

1

Chapter 8—Safety Design Section 8B-10—Tabulating Guardrail

Page 4 of 9

Example 3—Steel Beam Guardrail over a Low-fill Culvert

Bid

Ite

ms

Lay

ou

t L

en

gth

s

WB

Lane

EB

Lan

e

VT

1 =

25.0

Obsta

cle

T

D0=

10.0

’

Offset=

22

.0’

AV

T1 =

18.8

ET=50.0

VF =25.0

AET=50.0

1319+00

1320+00

1321+00

BA

-200=

62.5

BA-205

BA-205

Sta

13

20

+0

0.0

0

Chapter 8—Safety Design Section 8B-10—Tabulating Guardrail

Page 5 of 9

Example 4—Side Obstacle Shielded with Steel Beam Guardrail (Two-way Protection)

399+00

400+00

401+00

Bid

Ite

ms

Lay

ou

t L

en

gth

s

EB

Lan

e

EB

Lan

e

Offset=

77

.0’

VT

1 =

12.5

T

EA

=9.4 D0=

10.0

’

18.8

VT

1 =

A

12.5

VT

2 =

A

ET=50.0

VF =25.0

A

BA

-203

BA-200=62.5

BA-205

Sta

40

0+

00

.00

Chapter 8—Safety Design Section 8B-10—Tabulating Guardrail

Page 6 of 9

Example 5—Side Obstacle Shielded with Steel Beam Guardrail (One-way Protection)

EB

Lan

e

EB

Lan

e

WB

Lane

WB

Lane

Bid

Ite

ms

C =

139.1

C0

=4

0.0

Prote

cti

on L

ength

=179.1

A

D0=

20.5

’

199+00

198+00

200+00

201+00

Dim

en

sio

ns

Bridge P

iers

End A

nchor

End A

nchor

(L

ength

Varie

s)

(L

ength

Varie

s)

Sta

20

1+

59

.10

Sta

19

8+

40

.90

Chapter 8—Safety Design Section 8B-10—Tabulating Guardrail

Page 7 of 9

Example 6—Median Obstacle Shielded with High-tension Cable Guardrail

Layout

Length

s &

Dim

ensio

ns

Bid

Ite

ms

498+00

499+00

500+00

BA

-202

Offset=

22

.0’

VT

1=

53

.1ET=37.5

D0=

10.0

’

C =

500.0

A

Anchor S

ecti

on

Sp

ecial

Protection Length=500.0

D0

=1

2.0

EB

Lan

e

WB

Lane

50.0

’

50.0

’50:1 Taper =100.0’

BA

-201

BA-206

BA

-2

00

=2

5.0

Sta

50

0+

00

.00

Sta

49

9+

90

.87

Sta

50

0+

45

.87

Sta

50

0+

55

.00

501+00

Chapter 8—Safety Design Section 8B-10—Tabulating Guardrail

Page 8 of 9

Example 7—High-tension Cable Guardrail Attached to Steel Beam Guardrail (Case 1)

198+00

199+00

200+00

BA

-202

VT

1=

28

.1

Anchor S

ecti

on

Sp

ecial

Prote

cti

on L

ength

=800.0

D0=

11.0

’

C =

800.0

A

ET=37.5

VT

2=

25

.0VF=50.0

EB

Lan

e

EB

Lan

e

Offset=

25

.2’

Offset=

66

.8’

Bid

Ite

ms

Layout

Length

s &

Dim

ensio

ns

50

.0’

BA

-201

BA-200=75.0

BA-206

Sta

19

9+

56

.09

Sta

19

9+

74

.75

Sta

19

8+

23

.26

Chapter 8—Safety Design Section 8B-10—Tabulating Guardrail

Page 9 of 9

Example 8— High-tension Cable Guardrail Attached to Steel Beam Guardrail (Case 2)

Chronology of Changes to Design Manual Section:

008B-010 Tabulating Guardrail4/29/2011 Revised

Updated examples for the BA series and added examples with high-tension cable guardrail.

6/18/2004

Previously Updated.