007 deck drains

8/18/2019 007 Deck Drains

1/38

Kansas Department of Transportation Design Manual

Volume III US (LRFD) Bridge Section

Version 9/13 3 - 8 - i

3.8 BRIDGE DECK DRAINAGE

Table of Contents

3.8.1 General ..................................................................................................................1

3.8.2 Design/Procedures .................................................................................................33.8.2.1 Design Spread and Rainfall Frequency .....................................................................3

3.8.2.2 Design Q and Rainfall Intensity................................................................................ 3

3.8.2.3 Drain Location ...........................................................................................................4

3.8.2.4 Top Width .................................................................................................................5

3.8.3 Design Example #1 - Scuppers on Vertical Curves ..............................................6

3.8.4 Design Example #2 - Grates on vertical curve ....................................................16

3.8.5 Drain Details .......................................................................................................26

List of FiguresFigure 3.8.1-1 Prestress Beam Protection. .....................................................................................2

Figure 3.8.3-1 Kinematic wave formulation Chart #1 ....................................................................9

Figure 3.8.3-2 Scupper Requirement Nomograph ........................................................................10

Figure 3.8.3-3 Bridge Deck Drainage (8" x 6" Scuppers) ............................................................15

Figure 3.8.4-1 Chart #2 - Velocity in triangular gutter sections ...................................................19

Figure 3.8.4-2 Chart #7 - Grate inlet frontal flow interception efficiency ...................................20

Figure 3.8.4-3 Chart #8 - Grate inlet side flow interception efficiency ........................................21

Figure 3.8.4-4 P-1-7/8 and P-1-7/8-4 grates .................................................................................22

Figure 3.8.4-5 Example #2 - Grate Inlet Capacity ........................................................................24

Figure 3.8.4-6 Bridge Deck Drainage (1’x 3’ Grates) ..................................................................25

Figure 3.8.5-1 Inlet detail showing formed blockout under inlet box ..........................................27Figure 3.8.5-2 Example: Grate Inlet on Steel Girder Bridge ........................................................28

Figure 3.8.5-3 Example: Grate Inlet on Steel Girder Bridge ........................................................29

Figure 3.8.5-4 Example: Grate Inlet on Steel Girder Bridge ........................................................30

Figure 3.8.5-5 Example: Grate Inlet on Prestressed Girder Bridge ..............................................31

Figure 3.3.5-6 Example: Scupper on Steel Box Girder Bridge ....................................................32

Figure 3.3.5-7 Example: Scupper on Prestressed Bridge .............................................................33

Figure 3.3.5-8 Example: Scupper on Steel Girder Bridge ............................................................34

Figure 3.3.5-9 Example: Scupper on T-Girder Bridge .................................................................35

Figure 3.3.5-10 Typical Drainage System Details ........................................................................36


2/38



Version 9/13 3 - 8 - ii

Disclaimer:

Disclaimer: This document is provided for use by persons outside of the Kansas Department of

Transportation as information only. The Kansas Department of Transportation, the State of Kansas, its

officers or employees, by making this document available for use by persons outside of KDOT, do notundertake any duties or responsibilities of any such person or entity who chooses to use this document.

This document should not be substituted for the exercise of a persons own UProfessional Engineering

JudgementU. It is the users obligation to make sure that he/she uses the appropriate practices. Any

person using this document agrees that KDOT will not be liable for any commercial loss; inconvenience;

loss of use, time, data, goodwill, revenues, profits, or saving; or any other special, incidental, indirect, or

consequential damages in any way related to or arising from use of this document.

Typographic Conventions:

The typographical convention for this manual is as follows:

Non italic references refer to locations within the KDOT Bridge Design Manuals (either the LRFD or LFD),

or Hyper links shown in red, as examples:

Section 3.2.9.12 Transportation

Table 3.9.21 Deck Protection

Italic references and text refer to locations within the AASHTO LRFD Design Manual, for example:

Article 5.7.3.4

Italic references with a LFD label and text refer to locations within the AASHTO LFD Standard

Specifications, for example:

LFD Article 3.5.1


3/38



Version 9/13 3 -8 - 1

3.8 BRIDGE DECK DRAINAGE

3.8.1 General

Effective bridge deck drainage is important since poor drainage may lead to the following

problems:

a) Increased corrosion of structural and reinforcing steel by deicing chemicals.

b) Ice forming on the deck.

c) Hydroplaning.

Bridge-deck drainage systems are a continual maintenance problem; therefore, the designer

should eliminate drains on bridges when they are unnecessary. A drain-free bridge may be

achieved by using open bridge rails. Where curbs are required, the designer can take advantage of

the shoulder section provided on most of today’s bridges by using it as a gutter. If the runoff com-

ing to the bridge is removed before it runs onto the bridge, the hydraulic capacity of the shouldermay be great enough to eliminate the need for bridge drains on short bridges.

Inlet structures located immediately off the end of the bridge should be designed in collaboration

with the road section to determine when and where they are needed. This coordination also helps

to avoid conflicts with other bridge or roadway structures such as guard fence posts which could

interfere with the drainage flow.

Short continuous span bridges, particularly overpasses, may be built without inlets on the bridge

and the water carried downslope by a flume or inlet structure near the end of the bridge. An open

flume down the sideslope or foreslope is preferred because the concrete flume is more accessible

for maintenance and repair.

On long bridges, drainage should be provided by scuppers or grates of sufficient size and number

to adequately drain the gutters and limit the encroachment of water in the driving lanes.

On bridges containing open-type expansion devices, drains should be located to pick up as much

drainage as possible before it crosses the device. Glands shall be placed in finger devices to carry

drainage; however maintenance cleaning of these troughs and other inlets and grates may be

limited. Drainage design and details should provide the necessary hydraulic capacity with a

minimum of required maintenance. Conservative assumptions of hydraulic capacity is encour-

aged to provide drainage operation based on limited maintenance. (50% inlet efficiency is a good

rule.)

Coat the top of Prestressed Beams with “Substructure Waterproofing Membrane” where the deck

drains are located to prevent leaks from compromising the member.


4/38



Version 9/13 3 - 8 - 2

Figure 3.8.1-1 Prestress Beam Protection.


5/38


6/38

tc



Version 9/13 3 - 8 - 4

Where:

= time of overland flow, seconds

L = overland flow length, ft.

n = Manning roughness coefficient (.016 for bridge decks)

i = rainfall rate, in./hr.

S = average slope of the overland area, ft./ft.

The solution is one of trial and error. Estimate the location of a drain to get ’L’ and select ’i’ for an

assumed 5 minute storm from the Rainfall Intensity Tables for Kansas. (If Kansas Rainfall Inten-

sity Tables are not available, refer to Appendix A of HEC 12 (1984) for development of intensity-

duration-frequency curves using NWS HYDRO-35 maps.) Reiterate until the assumed storm

duration equals the computed . If is less than 5 minutes it is KDOT policy to use the 5 min-

ute storm for the design of bridge drains. The maximum intensity need not exceed 6 inches per

hour. (Experience has shown when the intensity of rainfall exceeds 6 inches per hour, a drivers

vision becomes substantially obscured because the capacity of the windshield wipers is exceeded.

Operational speed is therefore voluntarily reduced and the probability of hydroplaning is

less.)(Ref.1)

3.8.2.3 Drain Location

Many factors are involved in determining the location of drains on bridges. It is KDOT Policy not

to let drainage fall within the width of railroad ballast or to fall on the shoulder to shoulder width

of road under a highway overpass. Drains for overpasses can be placed near abutments to drop on

protected berms. For locations susceptible to erosion, consider widening the shadow line riprap or

the use of crushed stone splash blocks. Locate drains far enough away from Bridge Seats to pre-

vent drainage (especially wind blown drainage with deicer chemicals) from falling on the con-

crete.

Where discharge from the inlets cannot be allowed to fall freely on to underlying areas, locate

inlets directly above the downspouts attached to the substructure. Avoid midspan locations result-

ing in complex, lengthy piping whenever it is possible.

For bridges located in a sag vertical curve, place a drain at the low point of the curve. Since there

is a tendency for grates to become clogged, consideration should be given to using a combined

grate and curb opening inlet. Place inlets on both sides of the low point inlet. Place these flanking

inlets so they will limit the spread of water on low gradient approaches and also act in relief of the

inlet at the low point if it should become clogged. HEC 12 (1984) should serve as a guide to these

designs.

At superelevation transitions where the cross slope reverses from full crown to full supereleva-

tion, exercise care to avoid impoundments and to eliminate cross road flow.

tc tc


7/38

Q =K Sx

5/3S

1/2 T

8/3

n-----------------------------------------



Version 9/13 3 -8 - 5

3.8.2.4 Top Width

The design top flood width should not be greater than widths given under Section 3.8.2.1 Design

Spread and Rainfall Frequency above for the class of road.

A modified Mannings equation which compensates for gutter flow may be used in calculation ofthe capacity of the gutter.

Where K = a constant (0.56)

Sx = cross slope (road crown slope), ft./ft.

S = road grade, ft./ft.

T = top width of flow, feet

n = 0.016

Q = flow rate, cubic feet/second

and

References:

For additional information on pavement drainage refer to:

1) FHWA, “Bridge Deck Drainage Guidelines”, Final Report, December, 1986.

2) FHWA, “Drainage of Highway Pavements”, Hydraulic Engineering Circular No.

12, March 1984.

3) Transportation Research Board, “Bridge Drainage Systems” NCHRP Synthesis of

Highway Practice 67, National Research Council, Washington, D.C., December

1979, pp. 1-44.

4) FHWA, “Design of Bridge Deck Drainage”, Hydraulic Engineering Circular No.

21, May 1993.

T =n Q

K Sx 5/3

S1/2

---------------------------------3/8


8/38



Version 9/13 3 - 8 - 6

3.8.3 Design Example #1 - Scuppers on Vertical Curves

References:

1) “Bridge Deck Drainage Guidelines” FHWA December, 1986

2) HEC 12, 1984

Problem: Design scuppers in Area I for a 500-foot interstate bridge located in John-

son County, Kansas, based upon the following information:


9/38



Version 9/13 3 -8 - 7

1. Find the distance from the PC to the high point of the curve.

a) compute algebraic difference A = g1-(g2)

(g1,g2 in%) = + 10-(-0.5)

= + 1.5

b) k (a constant) =A

2L-------

1.5

2 10( )-------------- 0.075= =

(L in stations)

c) r = rate of change (constant) =A

L----

1.5

10------- 0.150= =

d) slope at a point = g1 - r(x)

Location of high point: xt = g12k ------ + 1.00

2 0.075( )--------------------- 6.667 Sta.= =

P.C. Sta. = 95 + 00

+ 6 + 66.7

101 + 66.7 = Sta. of high point

Elevation of high point: Elev. P.C. + g1 (xt) - k(xt)2

= 820.00 + (10 x 6.667) - (0.075)(6.667)2

= 823.33

Allowable spread: Urban area, high volume traffic - Use 10’ right shoulder

(T = 10’-0”)

W = 35.33’ (width of lane + curb)

S (slope) @ high point = 0.0

S @ end of bridge = + 10 - (0.150)(97.50 - 95.0)

= 0.625% = .00625 ft./ft.

Sx (transverse slope) =.0156 ft./ft. = 3/16” / ft.

Distance from high point to end of bridge = 416.7’


10/38



Version 9/13 3 - 8 - 8

2. Determine if drains are needed by nomograph or calculation.

a) Need to determine Rainfall Intensity (i) which depends on the storm duration

(which is equal to the time of concentration) and to the recurrence interval.

The time of concentration may be estimated from Chart 1, Figure 3.8.3-1 Kinematic wave

formulation Chart #1or from the Kinematic Wave Equation:

tc 56L0.6n0.6

i0.4s0.3-------------------------=

Assume tc = 5 min., then for Johnson Co. and a 10-year storm, i = 9.11 in/hr. (from Kansas

Rainfall Intensity tables. 1981)

@EWS:

tc 56 416.7( )

0.6

0.016( )

0.6

9.11( )0.4

0.00625( )0.3-------------------------------------------------------= = 331 secs.

= 5.52 min.

(close enough)

Use Max. i = 6 in/hr. See Section 3.8.2.2 Design Q and Rainfall Intensity

b) Determine L.

“L” by nomograph = 250’ See Figure 3.8.3-2 Scupper Requirement Nomograph

“L” by calculation:

L =24393.6

C n-------------------

Sx1.67

S0.5

T2.67

i w---------------------------------

=24393.6

0.9( ) 0.016( )-------------------------------

0.0156( )1.67

0.00625( )0.5

10( )2.67

6(35.33)-------------------------------------------------------------------------------

= 284’ < 416.7’ therefore need drains in Area I to intercept flow.


11/38



Version 9/13 3 -8 - 9

Figure 3.8.3-1 Kinematic wave formulation Chart #1


12/38



Version 9/13 3 - 8 - 10

Figure 3.8.3-2 Scupper Requirement Nomograph


13/38



Version 9/13 3 -8 - 11

3. Find scupper efficiency.

Use 8" x 6" scupper (W = 8", L = 6")

E = Scupper interception efficiency = 1 - 1-W

T

-----2.67

(A good approximation for small grates and low gutter velocities.)

E = 1 - 1-0.67

10----------

2.67

0.169 (approximately 17%)=

4. Find distance to first scupper from high point (where spread reaches 10’-0”).

Since “S” is variable;

L = (16.94 x 105 )0.0156( )

1.67 10( )

2.67

212-------------------------------------------------- S

0.5

L = 3,590 S0.5

Use trial and error to get distance from high point equal to’L’ from formula.

Distance from

Station High Point S Computed L

100+66.7 100’ 0.0015 139’

100+16.7 150’ 0.00225 170’

99+66.7 200’ 0.0030 197’

∴ L is near Sta 99 + 66.7

Try:

99+80 187’ 0.0028 190’

(Close enough)

Distance to 1st scupper = 187’

Gutter flow at 1st scupper =

QR1 = c i a = 0.9(6.0) x35.33 187( )

43 560,--------------------------- = 0.819 cfs


14/38



Version 9/13 3 - 8 - 12

Where: c = 0.9

i = 6.0 in./hr.

a =W L

43 560,------------------ = drainage area in acres

Intercepted flow at 1st scupper:

q1 = E QR1 = 0.169 (0.819) = 0.14 cfs

5. Determine distance (l1) to 2nd scupper.

QR2 = 0.9 (6.0) x35.33 (L + l1 )

43 560,---------------------------------- - 0.14 cfs

= 0.00438 (L + l1) - 0.14

also, QR2 =0.56

n---------- Sx

1.67 S2 0.5 t2.67

=0.56

0.016------------- (0.0156)1.67 S2

0.5 t2.67

solving for t =29.745QR2

S20.5

--------------------------0.375

(for trial values of t)

Trials to get t = T = 10’0”:

try l1 = 50’ L + l1 = 187 + 50 = 237’ (Sta. 99+30);

S2 = 0.00355

QR2 = 0.00438(237) - 0.14 = 0.898 cfs

t =29.745 0.898( )

0.00355( )0.5

-----------------------------------0.375

= 13.075’ is not less than 10.0’

too much spread, try l1 = 35’

∴ L + l1 = 222’ (Sta. 99+45); S2 = 0.003325

QR2 = 0.00438(222) - 0.14 = 0.832 cfs


15/38



Version 9/13 3 -8 - 13

t =29.745 0.832( )

0.003355( )0.5

-----------------------------------0.375

= 9.71’ < 10.0’ (close enough)

∴ distance to 2nd scupper = 35’ (Sta. 99 + 45)

Intercepted flow at second scupper:

q2 = E QR2 = 0.169 x 0.832 = 0.14 cfs

6. Determine distance, l2, to 3rd scupper.

try l2 = 50’: L + l1 + l2 = 187 +35 + 50

= 272’ (Sta. 98 + 95)

S3 = 0.0041

QR3 = 0.00438(272 - 0.14 - 0.14) = 0.911 cfs

t =29.745 (0.911)

0.0041( )0.5

-----------------------------------0.375

= 9.7’ < 10.0" (close enough)

q3 = 0.169 x 0.911 = 0.154 cfs

7. Determine distance, l3, to 4th scupper.

Try l3 = 75’: L + l1 + l2 + l3 = 347’ (Sta. 98 + 20)

S4 = 0.0052

QR 4 = 0.00438(347) - 0.14 - 0.14 - 0.154 = 186 cfs

t =29.745 (1.086)

0.0052( )0.5

-----------------------------------0.375

= 9.9’ < 10.0’ (close enough)

q4 = 0.169 x 186 = 0.184 cfs

(locate 5th scupper near end of bridge)

8. The number of scuppers required by the above procedure should be considered a mini-

mum. The final scupper spacing still requires some engineering judgement.

Allowance should be made for the inevitable clogging of scuppers with debris. A factor of

safety of two has been suggested. Scuppers should also be spaced to clear piers and facili-

tate construction.


16/38



Version 9/13 3 - 8 - 14

Drainage from scuppers in the end span would fall on the berm so the berm are to be

protected by slope paving, dumped rock or drain troughs.

If drainage cannot be discharged thru vertical downspouts, and a drainage system is

required, it may be more economical to use grates located near piers supporting the down-

spouts.

Drainage off the end of the bridge needs to be picked up by a grate inlet or by a concrete

flume directing the flow down the side slope.

See Bridge Deck Drainage (8" x 6" Scuppers) sheet, Figure 3.8.3-3 Bridge Deck Drainage

(8" x 6" Scuppers) for final scupper spacing.


17/38



Version 9/13 3 -8 - 15

Figure 3.8.3-3 Bridge Deck Drainage (8" x 6" Scuppers)


18/38



Version 9/13 3 - 8 - 16

3.8.4 Design Example #2 - Grates on vertical curve

(Ref. HEC #12, March 1984, p.53)

Problem: Re-design Example #1 using grates instead of scuppers. In addition, design for

all drainage to be removed before reaching the expansion joint.

1. Determine efficiencies for various grate sizes.

Using: T(max) = 10.0’

c = 0.9

n = 0.016

Sx = 0.015625 ft./ft.

S = 0.00625 ft./ft. (grade at EWS)

The efficiency, E, of a grate is expressed as:

E = R f Eo + R s (1 - Eo)

The first term on the right side of the above equation is the ratio of intercepted frontal flow

to total gutter flow, and the second term is the ratio of intercepted side flow to total side

flow. The second term is insignificant with high velocities and short grates.

The interception capacity of a grate inlet on grade is equal to the efficiency of the grate

multiplied by a total gutter flow:

Qi = Interception capacity = E Q

a) Compute Eo:

Eo = Qw / Q = 1 - (1 - W/T)2.67

Eo = ratio of frontal flow (flow passing over the grate) to total gutter flow.

Qw = flow in width W, cfs

Q = total gutter flow, cfs

W = width of depressed gutter or grate, ft.

T = total spread of water in gutter, ft. (max. 10’)

for W = 2, Eo = 0.449W = 3, Eo = 0.614

W = 4, Eo = 0.744

b) Find R f factor, which is the ratio of frontal flow intercepted to total frontal flow.

R f = 1 - 0.09 (V - Vo)

V = Velocity of flow in gutter


19/38



Version 9/13 3 -8 - 17

Vo = Velocity where splash-over first occurs

(Note: If Vo > V, then R f = 1)

V can be determined from Chart 2, see or from the equation:

V =1.12

n---------- S0.5 Sx

0.67 T0.67

Vo can be determined from Chart 7, see Figure 3.8.4-2 Chart #7 - Grate inlet fron-

tal flow interception efficiency

Assume a grate similar to P-1-7/8-4. This grate is not as efficient as P-1-7/8, but is

bicycle safe. see Figure 3.8.4-4 P-1-7/8 and P-1-7/8-4 grates

For this example:

V =1.12

0.016------------- (0.00625)0.5 (0.015625)0.67 (10)0.67

V = 1.60 ft./sec.

Find Vo (Chart 7): for L = 1, Vo = 3.0

L = 1.5, Vo = 3.8

L = 2.0, Vo = 4.7

L = length of grate along the gutter

Since Vo is greater than V in all cases, R f will be equal to 1 for this example.

c) Find R s factor, which is the ratio of side flow intercepted to the total side flow.

1

R s = 1 + 0.15 V1.8

Sx L2.3

(R s can also be determined from Chart 8)

Assuming V = 1.60 ft./sec. and Sx = 0.015625, find R s:

For L = 1, R s = 0.043

For L = 1.5, R s = 0.102

For L = 2.0, R s = 0.180


20/38



Version 9/13 3 - 8 - 18

Compute efficiencies for the various grate sizes listed below: E = R f Eo + R s (1 - Eo)

L W R f Eo R s E

1 x 2 1 0.449 0.043 0.473

1 x 3 1 0.614 0.043 0.6311.5 x 2 1 0.449 0.102 0.505

1.5 x 3 1 0.614 0.102 0.653

2 x 2 1 0.449 0.180 0.548

2 x 3 1 0.614 0.180 0.684

Due to the rather flat grades with resulting low gutter velocities, the more efficient grates

are wider, narrow ones. Even though the chart shows the 2 x 3 grate to be the most effi-

cient for this particular example, the 1 x 3 grate appears to be the most cost effective since

reducing the inlet size by 200 percent, only decreases the grate efficiency by 8 percent.


21/38



Version 9/13 3 -8 - 19

Figure 3.8.4-1 Chart #2 - Velocity in triangular gutter sections


22/38



Version 9/13 3 - 8 - 20

Figure 3.8.4-2 Chart #7 - Grate inlet frontal flow interception efficiency


23/38



Version 9/13 3 -8 - 21

Figure 3.8.4-3 Chart #8 - Grate inlet side flow interception efficiency


24/38



Version 9/13 3 - 8 - 22

Figure 3.8.4-4 P-1-7/8 and P-1-7/8-4 grates


25/38



Version 9/13 3 -8 - 23

2. Determine grate spacing required using 1 x 3 grates.

Space inlets to keep the pavement spread (T) to a maximum of 10’-0”, then add extra

grates at the end of bridge as needed to remove all runoff.

From Example #1, the width of flow approaches 10 feet at 187 feet from the high point.

Therefore locate the first drain at Sta. 99 + 80.

At Sta. 99+80, Q = 0.83 cfs (from Ex. #1). From the chart showing grate efficiencies (par.

1.C), E for 1 x 3 grate is 0.631.

Qi = E Q = 0.631 x 0.82 = 0.517 cfs

Find approximate grate spacing allowed if inlet capacity is 0.517 cfs.

L =q (43,560)

c i w

-------------------------

L =0.517 x 43,560

0.9 x 6 x 35.33------------------------------------ = 118 feet

Try grate spacing of 100 feet.

See next page for table computing interception capacities of grates on variable grade.

The side flow of a 1 foot long grate could probably be disregarded with negligible error;

however, for illustration purposes it will be included.

As shown on the next page, five drains are sufficient to remove the runoff from the bridge.

However, additional drains should be added to account for the possibility of drains plug-

ging up. Based on the recommendation of a 50% clogging potential, reduce spacing from

100 feet to 50 feet.

See Bridge Deck Drainage (1 x 3 Grates) sheet, Figure 3.8.4-6 Bridge Deck Drainage (1’x

3’ Grates) for final grate spacing.


26/38



Version 9/13 3 - 8 - 24

Figure 3.8.4-5 Example #2 - Grate Inlet Capacity


27/38



Version 9/13 3 -8 - 25

Figure 3.8.4-6 Bridge Deck Drainage (1’x 3’ Grates)


28/38



Version 9/13 3 - 8 - 26

3.8.5 Drain Details

Drains not only need to be hydraulically efficient, they also need to be safe, strong and maintain-

able.

Grates generally work most efficiently when the slots parallel the water flow. However, crossbarsshould be placed in the grate perpendicular to traffic to prevent a bicycle tire from falling in.

Grates should be strong enough to carry all highway loads and must be securely fastened to pre-

vent traffic from flipping them out. Positive bolted hold-downs should be used to allow removal

of grates for maintenance purposes.

Inlets on deck-girder bridges should be designed to prohibit concrete from getting under the inlet

box The bottom of the inlets taper to near the bottom of the deck, creating a small sliver of con-

crete under the inlet which is susceptible to spalling. Use a formed block-out to prevent this. See

detail on the next sheet.

Short, vertical downspouts should be made of rigid corrosive-resistant material not less than 6

inches in the least dimension and should be provided with cleanouts. All drain downspouts shall

be located at the curb line and shall extend a minimum of 12 inches below the bottom flange of

steel girders.

Where collection systems are required, pipes should not be smaller than 10 inches in diameter.

Mild steel, wrought iron as well as fiberglass pipes should be considered for use. Slopes of all

pipes should be as steep as possible and runs should be as short as practical. A minimum slope of

1 in./ft. for horizontal runs is recommended.

Detail elbows with a minimum 12 inch inside radius on bend angles greater than 22 ½ degrees.At "y’s", the outgoing pipe should be larger than either of the incoming pipes to minimize clog-

ging. Provide accessible cleanouts at all bends.


29/38



Version 9/13 3 -8 - 27

Figure 3.8.5-1 Inlet detail showing formed blockout under inlet box


30/38



Version 9/13 3 - 8 - 28

Figure 3.8.5-2 Example: Grate Inlet on Steel Girder Bridge


31/38



Version 9/13 3 -8 - 29



32/38



Version 9/13 3 - 8 - 30



33/38



Version 9/13 3 -8 - 31

Figure 3.8.5-5 Example: Grate Inlet on Prestressed Girder Bridge


34/38



Version 9/13 3 - 8 - 32

Figure 3.3.5-6 Example: Scupper on Steel Box Girder Bridge


35/38



Version 9/13 3 -8 - 33

Figure 3.3.5-7 Example: Scupper on Prestressed Bridge


36/38



Version 9/13 3 - 8 - 34

Figure 3.3.5-8 Example: Scupper on Steel Girder Bridge


37/38



Version 9/13 3 -8 - 35

Figure 3.3.5-9 Example: Scupper on T-Girder Bridge


38/38


Figure 3.3.5-10 Typical Drainage System Details

007 deck drains

Documents