highway drainage system efficiency

7/24/2019 Highway Drainage System Efficiency

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Highway Drainage SystemHighway Drainage System

EfficiencyEfficiency

University of Zagreb CroatiaUniversity of Zagreb Croatia

Faculty of Civil EngineeringFaculty of Civil EngineeringDavor Malus, h!D!CEDavor Malus, h!D!CE

DraDra""en #ou$, %!Sc!CEen #ou$, %!Sc!CE


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OSBMP

OGS

Typical highway drainage schemeTypical highway drainage scheme

Open/closedconduit

drainagearea


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Swiss regulations for OGS dimensioning:Swiss regulations for OGS dimensioning:

ikr= ! l/s/ha "#$ e%ceedance&'ydraulic loading OB () m/h

*roatian practice:*roatian practice:

ikr= # l/s/ha

ikr= +! l/s/ha

ikr= +# l/s/ha

OIL

C&'SE(U'CE) bigger &*S an+ construction costsC&'SE(U'CE) bigger &*S an+ construction costs


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(uestion)(uestion)

Contribution of higher i$rto overall

+rainage efficiency


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&S

%M

,!$eff-in .. remoal

Drainage scheme

0=km

1 = !-#$

2 = +! m

3kr= ikr45 4 c

6o= 6 7 3kr

11

Solution)Solution)


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12

1

+

=

C

tCB

C1= ma%imum 8uild7up possi8le ",! kg/ha&

C2= half7saturation constant "# days&

BqCW C = 21

C1= washoff coefficient "!-&

C2= washoff e%ponent "&

B = pollutant 8uildup in mass "kg& per unit area

DD washoffDD washoff

DDDDbuil+u-buil+u-

22

E. S/MM0


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2eather serice stations:

- Slaonski Brod 's = 9!! mm/year

+- Parg 's = +!! mm/yearPeriod +!! +!!(

#7minute rainfall data

km long; +! m wide; with

!;#$ slope

33 1wo areas with +ifferent climatic characteristic1wo areas with +ifferent climatic characteristic

44 1wo com-letely same sections of highway1wo com-letely same sections of highway


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2ainfall +ata statistics2ainfall +ata statistics55

02

4

6

8

10

12

14

16

18

10 15 20 25

ikr (l/s/ha)

Exceedance

(%)

S.Brod

Par


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#olume of untreate+3treate+ runoff#olume of untreate+3treate+ runoff

0

5

10

15

20

25

10 15 20 25

ikr (l/s/ha)

!"/!# (%) S.Brod

Par

66


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Mass of untreate+3treate+ DD from runoffMass of untreate+3treate+ DD from runoff

0

2

4

6

8

1012

14

16

18

20

10 15 20 25

ikr (l/s/ha)

$$"/$$#

(%)

S.Brod

Par


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Mass of treate+3total DD emissionMass of treate+3total DD emission

0

10

20

30

40

50

60

0

10 15 20 25

ikr (l/s/ha)

$$#r/$$#o#

(%)

S.Brod

Par

88


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&verall treatment efficiency&verall treatment efficiency

4%M efficiency 56784%M efficiency 5678

0

5

10

15

20

2530

35

40

45

50

10 15 20 25

ikr (l/s/ha)

E&&. (%) S.Brod

Par

'


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ConclusionConclusion1ncreasing of i1ncreasing of ikrkrfrom !7+# l/s/ha results in only #7)$ increasingfrom !7+# l/s/ha results in only #7)$ increasing

of oerall efficiency-of oerall efficiency-

The critical intensities of rainfall a8oe # l/s/ha are generallyThe critical intensities of rainfall a8oe # l/s/ha are generally

unreasona8ly high-unreasona8ly high-

'ighway drainage designers should calculate proper critical'ighway drainage designers should calculate proper criticalintensity fromintensity from prescri8edprescri8ede%ceedance fre3uencies or oeralle%ceedance fre3uencies or oerall

treatment efficiency-treatment efficiency-

highway drainage system efficiency

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