HECRAS Bridges HECRAS xidebi

1
HECRAS BridgesHECRAS xidebi

• by G. Parodi
• WRS ITC The Netherlands
• g. parodi
• WRS-ITC- niderlandebi

2
How does a bridge affect the hydraulics?rogor
zegavlenas axdens xidi hidravlikaze?

• Contraction
• konstruqcia
• Through the bridge
• xidis gaswvriv
• Piers
• pirsi
• Abutments
• TaRis/kamaras sayrdeni
• Bridge deck
• xidis savali nawili
• Expansion
• gafarToeba

2
3
3
2 Types of Flow at Bridgesxidis dinebis 2 tipi

• Low Flow - Flow where the water surface does not
  reach the low beam
• dabali dineba - dineba, sadac wylis zedapiri ar
  aRwevs xidis koWs
• High Flow - Flow where the water surface reaches
  the deck or higher
• maRali dineba - dineba, sadac wylis zedapiri
  aRwevs an cdeba xidis saval nawils

Q Is this low flow or high flow? kiTxva es
dabali dinebaa Tu maRali?
4
Low Flowdabali dineba
5
Low Flow Bridge Modeling 3 Types of Flowdabali
dinebis xidis modelireba dinebis 3 tipi
6
Low Flow Bridge Hydraulics 4 methods of
modelingdabal dinebiani xidis hidravlika
modelirebis 4 tipi

• Energy - physically based, accounts for friction
  losses and geometry changes through bridge, as
  well as losses due to flow transition
  turbulence.
• energia fizikur kanonebze dayrdnobiT iTvleba
  xaxunis danakargi da geometriuli cvlilebebi xidis
  gaswvriv iseve, rogorc dinebiT da turbulentobiT
  (areulobiT) gamowveuli danakargi.
• Momentum - physically based, accounts for
  friction losses and geometry changes through
  bridge.
• impulsi - fizikur kanonebze dayrdnobiT iTvleba
  kritikuli danakargi da xidis gaswvriv
  danakvirvebi geometriuli cvlilebebi.
• FHWA WSPRO - energy based as well as some
  empirical attributes. Developed for bridges that
  constrict wide floodplains with heavily vegetated
  overbank areas.
• FHWA WSPRO energiis kanonze dayrdnobiT, iseve
  rogorc zogierTi empiriuli atributi. SemuSavebulia
  xidebisTvis, romlebic gadaWimulni arian farTe
  mWidro mcenareuli safariT dafarul Walebze.
• Yarnell - empirical formula developed to model
  effects of bridge piers.
• Yarnell - empirikuli modeli SemuSavebulia xidis
  pirsebis efeqtebis modelirebisTvis.

7
Low Flow Bridge ModelingClass A Low Flow -
Energy Methoddabal dinebiani xidis modelirebaA
klasi dabali dineba energiis meTodi

• Friction losses are computed as length times
  average friction slope.
• xaxunis danakargis gaangariSeba xdeba rogorc
  sigrZe ayvanili saSualo xaxunis kuTxis xarisxSi.
• Energy losses are empirical coefficient times
  change in velocity head (expansion and
  contraction losses).
• energiis danakargi aris empirikuli koeficienti
  ayvanili siCqaris maqsimumis xarisxSi
  (gafarTovebis da SekumSvis danakargi)
• Does not account for pier drag forces.
• ar xdeba pirsebs damuxruWebis Zalis gaTvaliswineba

8
Low Flow Bridge ModelingClass A Low Flow -
Momentum Methoddabal dinebiani xidis
modelirebaA klasi dabali dineba impulsis meTodi

• Friction losses are external skin friction
  wetted perimeter times length times shear stress.
• xaxunis danakargi aris gare xaxuni sveli
  perimetri ayvanili sigrZis xarisxSi da ayvanili
  gadanacvlebis daZabulobis xarisxSi
• Requires entering coefficient of drag for piers,
  CD
• moiTxovs pirsebis damuxruWebis koeficientis
  damatebas

9
Low Flow Bridge ModelingCD Coefficients for Piers

• Circular Pier (wriuli pirsi) 1.20
• Elongated piers with semi circular ends
  (wagrZelebuli pirsi semiwriuli boloTi) 1.33
• Elliptical piers with 21 length to width
  (elipsuri pirsi) 21 Tanafardoba sigrZe
  siganesTan) 0.60
• Elliptical piers with 41 length to width
  (elipsuri pirsi) 41 Tanafardoba sigrZe
  siganesTan) 0.32
• Elliptical piers with 81 length to width
  (elipsuri pirsi) 81 Tanafardoba sigrZe
  siganesTan) 0.29
• Square nose piers (marTkuTxa xmauriani pirsi)
  2.00
• Triangular nose with 30 degree angle
  (triangularuli xmauri 30 gradusiani kutxiT)
  1.00
• Triangular nose with 60 degree angle
  (triangularuli xmauri 60 gradusiani kutxiT)
  1.39
• Triangular nose with 90 degree angle
  (triangularuli xmauri 90 gradusiani kutxiT)
  1.60
• Triangular nose with 120 degree angle
  (triangularuli xmauris 120 gradusiani kutxiT)
  1.72

10
Low Flow Bridge ModelingClass A Low Flow -
Yarnell Equationdabali dinebis xidis
modelirebaA klasis dineba-iarnelis gantoleba

• Based on 2,600 lab experiments on different pier
  shapes
• sxvadasxva formis pirsebis gamoyenebiT 2600
  laboratoriul eqsperimentze dayrdnobiT
• Requires entering pier shape coefficient, K
• moiTxovs pirsis formis koeficientis damatebas
• Should only be used where majority of losses are
  due to piers.
• unda gamoviyenoT mxolod iq, sadac ZiriTadi
  danakargi gamowveulia pirsebs arsebobiT

11
Low Flow Bridge ModelingYarnells Pier
Coefficient, Kdabali dinebis xidebis
modelirebaiarnelis pirsis koeficienti K

• Semi-circular nose and tail 0.90
• semi-cirkularuli xmauri da kudi
• Twin-cylinder piers with connecting diaphrag
  0.95
• ormagi cilindruli pirsi dakavSirebuli diafragmiT
• Twin-cylinder piers without diaphragm 1.05
• ormagi cilindruli pirsi diafragmis gareSe
• 90 degree triangular nose and tail 1.05
• 90 gradusiani triangularuli xmauri da kudi
• Square nose and tail 1.25
• marTkuTxa xmauri da kudi
• Ten pile trestle bent 2.50
• aTi gaerTianebuli sayrdeni

12
Low Flow Bridge ModelingClass A Low Flow
WSPROdabali dinebis xidis modelirebaA klasi
dabali dineba - WSPRO

• Federal Highway Administrations method of
  analyzing bridges
• federaluri gzatkecilis xidebis analizis
  administratoruli meTodi
• Uses energy equation in an iterative procedure
• gamoviyenoT energiis gantoleba iteraciuli
  (ganmeorebiTi) procedurebisTvis

13
Class B and C Low-flow MethodsB da C klasi-
dabali dineba

• Two methods available
• ori meTodia xelmisawvdomi
• Momentum - With irregular cross-section data and
  rapidly changing water surface elevation, the
  estimate of bed slope can be erratic. Therefore,
  the weight component is automatically turned off
  for Class B flow.
• Momenti (impulsi) araregularuli ganivi kveTebis
  monacemebiT da wylis zedapiris simaRlis uecar
  cvlilebebiani monacemebiT, SeiZleba kalapitis
  daxris kuTxis dadgena naklebi sizuzstiT moxdes.
  Sesabamisad wonis koeficienti avtomaturad
  gamousadegari xdeba dinebis b klasisTvis.
• Energy - During Class B flow, a dramatic change
  in depth can occur with resulting large changes
  in velocity head. Contraction and Expansion
  energy losses may be overestimated with
  traditional contraction and expansion
  coefficients.
• energia B klasis dinebis SemTxvevaSi, SeiZleba
  moxdes mniSvnelovani cvlileba wylis siRrmeSi,
  Sedegad gvaqvs maqsimalur siCqaris agdaWarbeba.
  gafarToveba da SekumSvis energiis danakargi
  SeiZleba gadaWarbebuli iyos tradiciuli
  gafarTovebis da SekumSvis koeficientebis
  gamoyenebiT.

14
Low Flow Bridge Hydraulics Summarydabali
dinebis xidebis hidravlika Sejameba

• Bridge piers are small obstruction to flow,
  friction losses predominate - Energy, Momentum,
  or WSPRO
• xidebis pirsebi mcire dabrkolebaa dinebisTvis,
  Warbobs xaxunis danakargi energia, impulsi an
  WSPRO
• Pier and friction losses predominate Momentum
• pirsi da xaxunis danakargi Warbobs - impulsi
• Flow passes through critical depth in vicinity of
  bridge - Energy or Momentum
• dineba kveTs kritikul siRrmes xidis midamoebSi
  energia an impulsi
• Pier losses are dominant Yarnell
• pirsis danakargi aris dominanti - iarneli
• Supercritical flow without piers - Energy or
  Momentum
• superkritikuli dineba pirsebis gareSe energia
  an impulsi
• Supercritical flow with piers Momentum
• superkritikuli dineba pirsebiT - impulsi

15
High Flow Bridge MethodsmaRali dinebis xidis
meTodi

• Energy Method - The area of the deck is
  subtracted and additional wetted perimeter is
  added. The water surface elevation represents
  the hydraulic grade line.
• energiis meTodi xidis savali nawili gamoiTvleba
  da damatebiTi sveli perimetri emateba. wylis
  zedapiris simaRle gviCvenebs hidravlikuri
  xarisxis xazs.
• This method does not account for the shape of the
  entrance or piers.
• es meTidi ar gamoiyeneba nakadis Serwymis
  moxazulobisTvis an pirsebisTvis
• Conveyance is calculated treating the bridge as a
  cross section, including flow over the roadway.
• gadazidvis gaangariSebisas xids ganvixilavT
  rogorc ganivi kveTs da moicavs dinebas
  gzatkecilis gadaRma.

16
High Flow Bridge MethodsmaRali dinebis xidis
meTodi

• (2) Pressure and Weir Method - Treats the flow as
  two separate components.
• (2) wneva da jebiris meTodi ganixilavs dinebas,
  rogorc ori gancalkevebuli komponents
• Flow through the opening is pressure flow.
• xidis Ria nawilis gaswvriv dineba aris
  Seviwroebuli (wnevis qveS myofi)
• Gate equation
• WiSkris gantoleba
• Full pressure (Orifice) equation
• sruli wnevis (naxvreti, Riobi) gantoleba
• Weir equation for flow over the roadway, with
  submergence correction.
• jebiris gantoleba gzis gadaRma, daZirvis
  SesworebebiT.

Note HECRAS will automatically select the
appropriate pressure flow equation. SeniSvna
HECRAS avtomaturad SearCevs swor wnevis dinebis
gantolebas
17
High Flow PressuremaRali dineba - wneva
18
High Flow - Pressure (Sluice) FlowmaRali dineba
Seviwroebuli (Sluzebi) dineba
Q Total discharge through the bridge
opening totaluri xarji xidis Ria nawilis
gaswvriv Cd Coefficient of discharge for
pressure flow xarjis koeficienti Seviwroebuli
dinebisTvis Abu Net area of the bridge opening
at section BU xidis Ria nawilis qselis zona BU
seqciaSi Y3 Hydraulic depth at section
3 hidravlikuri siRrme 3 seqciaSi Z
Vertical distance from maximum bridge low chord
to the mean river bed elevation at section
BU vertikaluri manZili xidis savali nawilis
umdables horizontamde da ZiriTadi mdinaris
kalapitis siRaRles Soris.
19
Coefficient of discharge for sluice gate
flowxarjis koeficienti Sluzebiani gasasvlelis
dinebisTvis
20
High Flow PressuremaRali dineba - wneva
21
High Flow - Pressure (Orifice) FlowmaRali dineba
Seviwroebuli dineba (naxvreti, Riobi)
Used when both the upstream and downstream sides
of the bridge is fully submerged gamoiyeneba,
rodesac xidis orive, zedadinebis da qvedadinebis
mxare sruliad aris daZiruli
Q Total discharge from full flowing
orifice Riobidan gamavali wylis sruli xarjva C
Coeff. of discharge for fully submerged pressure
flow sruliad daZiruli dinebis zewolis xarjis
koeficienti H The difference between the energy
gradient elevation upstream the water surface
elevation downstream gansxvaveba energiis
gradientisa da zedadinebis simaRles Soris wylis
zedapiris simaRle qvedadinebaSi A Net area of
the bridge opening xidis Ria nawilis qselis zona
22
High Flow - Pressure WeirmaRali dineba wneva
da wyalgadasaSvebi jebiri
23
High Flow - Weir FlowmaRali dineba
wyalgadasaSvebi jebiris dineba

• Q Total flow over the weir
• wyalgadasaSvebi jebiris sruli dineba
• C Coefficient of discharge for weir flow (2.5
  to 3.1 for free flow)
• xarjis koeficienti wyalgadasaSvebi jebiris
  dinebisTvis (2.5 - 3.1 Tavisufali dinebisTvis)
• L Effective length of the weir
• wyalgadasaSvebis efeqturi sigrZe
• H Difference between energy elev. upstream and
  road crest
• energiis simaRlis gansxvaveba zeadadinebasa da
  gzis kveTas Soris

24
High Flow SubmergencemaRali dineba - daZirva
daZiruli Semcirebis faqtori
daZirva
25
High Flow SubmergencemaRali dineba - daZirva
26
High Flow Bridge Modeling SummarymaRali dinebis
xidis modelireba daskvna

• When bridge deck is a small obstruction to the
  flow and not acting like a pressurized orifice,
  use energy method.
• rodesac xidis savali nawili warmoadgens mcire
  winaaRmdegobas dinebisTvis da ar moqmedebs rogorc
  zewolis xvreli, umjobesia gamoviyenoT energiis
  meTodi
• When overtopped and tailwater is not submerging
  flow, use pressure/weir method.
• rodesac datborva da Camonadeni wyali ar uerTdeba
  dinebas, gamoviyenoT wnevis/wyalgadasaSvebi
  jebiris meTodi.
• When overtopped and highly submerged, use energy
  method.
• rodesac xdeba datborva da Zlieri daZirva,
  gamoviyenoT energiis meTodi

27
Adding the Bridgexidebis damateba
28
Locating Cross-Sections Near Bridgesganivi
kveTebis ganlageba xidebTan
29
Locating Cross-Sections Near Bridgesganivi
kveTebis ganlageba xidebTan

• Equipotential lines Lc is a distance from the
  bridge where the flowlines remain parallel to the
  main flow direction and there is no contraction.
• ekvipotenciuri konturebi Lc aris manZili xidis
  im nawilidan, sadac dinebis konturi rCeba
  paraleluri ZiriTadi dinebis mimarTulebis mimarT
  da araa kumSvadi

30
Locating Cross-Sections Near Bridgesganivi
kveTebis ganlageba xidebTan
Fully Effective Flow sruliad efeqturi dineba
Fully Expanded Flow sruliad gafarTovebuli dineba
Thru Bridge xidis gavliT
Contraction SekumSva
Expansion gafarToveba
31
Locating Cross-Sections Near Bridgesganivi
kveTebis ganlageba xidebTan
Le
Lc
Fully Effective Flow sruliad efeqturi dineba
Fully Expanded Flow sruliad gafarTovebuli dineba
1
4
3
2
Lc and Le can be determined by field
investigation during high flow or can be
computed. Lc da Le SeiZleba ganvsazRvroT, rogorc
savele kvleva maRali dinebis dros an SeiZleba
gadaviTvaloT
32
Locating Cross-Sections Near Bridgesganivi
kveTebis ganlageba xidebTan
The contraction and expansions are normally
taken as linear in HECRAS gafarToveba da SekumSva
HECRAS-Si ganixileba rogorc wrfivi movlena
3
2
33
ExpansiongafarToveba

• FC2 Froude number at section 2 ricxvi 2 seqciaSi
• FC1 same at section 1 igive 1 seqciaSi

34
ContractionSekumSva

• Qob discharge conveyed at the two overbank
  sections (cfs).
• xarji or datborvis seqciaSi
• Q total discharge in the section (cfs)
• totaluri xarji seqciaSi
• nob Manning for the overbank sections
• maningis koeficienti Walis seqciaSi
• nc Manning for the channel.
• maningis koeficienti arxisTvis

35
Contraction/Expansion RatioSekumSvis/gafarTovebis
koeficienti
Rule of Thumb wesi
ER 21 CR 11
36
Contraction/expansion ratios - How do we use
them?SekumSvis/gafarTovebis koeficienti - rogor
viyenebT?
37
Example Computation of Le and LcLe da Lc s
gadaTvlis magaliTebi

• Given
• mocemulia
• Fully expanded flow top width at Cross Section 1
  300 feet
• sruliad gafarTovebuli dineba ganivi kveTis
  maqsimaluri sigane 1 300 futi
• Fully expanded flow top width at Cross Section 4
  250 feet
• sruliad gafarTovebuli dineba ganivi kveTis
  maqsimaluri sigane 1 250 futi
• Distance from Point B to Point C (bridge opening
  width) 40 feet
• distancia B wertilidan C wertilamde (xidis
  gaxsnili nawili) 40 futi
• Find Recommended locations of Cross Sections 1
  and 4
• ipoveT ganivi kveTis rekomendirebuli
  adgilmdebareoba 1 da 4
• Le 2 (300 40) / 2 260 feet downstream of
  bridge
• Le 2 (300 40) / 2 260 futi xididan
  qvedadinebisken
• Lc 1 (250 40) / 2 105 feet upstream of
  bridge
• Lc 1 (250 40) / 2 105 futi xididan
  zedadinebisken

This assumes ER2 and CR1 es uSvebs ER2 da CR1
38
Expansion Contraction CoefficientsSekumSvis da
gafarToebis koeficientebi
39
Expansion Contraction CoefficientsSekumSvis da
gafarToebis koeficientebi
  kumSva gafarToveba
araa gadasvla 0 0
TandaTanobiTi gadasvla 0.1 0.3
tipiuri xidis gadasvla 0.3 0.5
uecari gadasvla 0.6 0.8
40
Expansion and Contraction Example of
Coefficients at Bridge XSs SekumSva da
gafarToveba koeficientebis magaliTebi xidebze

• Expansion/ gafarToveba Contraction/
  kumSva
• Cross-Section 4 (furthest US) 0.5 0.3
• ganivi kveTi 4 (uSoresi zd)
• Cross-Section 3 0.5 0.3
• ganivi kveTi 3
• Cross-Section 2 0.5 0.3
• ganivi kveTi 2
• Cross-Section 1(furthest DS) 0.3 0.1
• ganivi kveTi 1 (uSoresi qd)

Use Cc 0.3 0.3 0.3
0.1 Cc-s gamoyeneba Use Ce
0.5 0.5 0.5
0.3 Ce-s gamoyeneba
41
Ineffective Flow Areasaraefeqturi dinebis are
2
1
3
4
42
Ineffective Flowsaraefeqturi dineba
The ineffective area option is used at bridge
sections 23 to keep all the active flow in the
area of the bridge opening until the elevations
associated with the left and/or right ineffective
flow areas are exceeded by the computed water
surface elevation!!! araefeqturi dinebis
parametri gamoiyeneba 2 da 3 xidis seqciebSi,
vinaidan xidis Ria nawilSi SevinarCunoT aqtiuri
dinebis areali im momentamde, sanam gamoTvlili
wylis zedapiris simaRle ar ascdeba marjvena an
marcxena araefeqturi dinebis arealis simaRles.
At XSs 2 3
43
Ineffective Flow Areasaraefeqturi dinebis are

• Enter stations that represent the active flow
  area at the cross section
• daamateT saguSagoebi, romlebic asaxaven aqtiuri
  dinebis ares ganivi kveTebis seqciebSi.
• (Adjust lateral distance for bounding sections
  distance from bridge)
• (miusadageT lateraluri distancia raTa
  ganvsazRvroT sazRvrebi xidisTvis)
• Enter elevation that allows overbank areas to
  become effective when exceeded
• SeiyvaneT simaRlis maCveneblebi, romlebic
  datborvis areebis efeqtur dinebad gadayvanis
  saSualebas mogvcemen, rodesac wyali ascdeba
  sazRvars
• Rule of Thumb
• wesi
• XS-2 gt Use elevation (low chord top of
  road)/2 for first estimate
• XS-2 gt gamoiyeneT simaRle (savali nawilis
  dabali horizonti gzis zeda horizonti)/2 pirveli
  SefasebisTvis
• Assume ER21 if flow can freely transition in
  out of bridge
• davuSvaT ER 21 Tu dinebas SeuZlia Tavisuflad
  gadavides xidze
• Width should normally be as wide or wider than
  bridge opening
• sigane rogorc wesi unda iyos ufro didi, an xidis
  napralze ufro ganieri.
• XS-3 gt Elevation should be set at top of road or
  slightly lower (0.1-0.2)
• simaRle unda mivuTiToT gzis zeda nawili an odnav
  dabali
• Assume a CR of 11 in the immediate vicinity of
  the bridge
• davuSvaT CR an 11 xidis uSualo siaxloves

44
Ineffective Flow Areasaraefeqturi dinebis are

• Define Ineffective Flow Areas if Needed
• Tu saWiroa gansazRvreT araefeqturi dinebis are
• From Bridge data page or from XS Options (Select
  Ineffective Flow Areas)
• xidebis monacemebis gverdidan an XS parametris
  gamoyenebiT (SearCieT araefeqturi dinebis are
  Ineffective Flow Areas)

45
Bridge Dataxidebis monacemebi
A word file has been developed to assist in
organizing the data at bridges vordis faili iyo
SemuSavebuli raTa daxmareba gaewia xidebTan
dakavSirebuli monacemebis organizaciaSi
es ar mitargmnia. vTargmno?
46
Bridge Dataxidebis monacemebi
A word file has been developed to assist in
organizing the data at bridges/culverts vordis
faili iyo SemuSavebuli raTa daxmareba gaewia
xidebTan dakavSirebuli monacemebis organizaciaSi
es ar mitargmnia. vTargmno?
47
Graphic to assist in visualizing the data at
bridgesgrafika xidebis vizualizaciis xelSewyoba
gawvdomis SekumSva
gawvdomis gafarToveba
dinebis gadaadgilebis idealuri mrudi 1D
modelirebisTvis
48
Q How would the flow expand below these
bridges? kiTxva rogor vrceldeba dineba xidis
qveS?
49
Adding the Bridgexidis damateba

• Select the Brdg/Culv button from the geometry
  data window
• SearCieT Brdg/Culv Rilaki geometriuli
  monacemebis fanjridan

50
Adding the Bridgexidis damateba

• This brings up the Bridge Culvert Data window
• ris Sedegadac gamoCndeba xidis wyalsadenis
  monacemTa fanjara

51
Adding the Bridgexidis damateba
There are several other options in the options
menu from the bridge data window as well as the
view menu xidebis monacemebis fanjaraSi,
parametrebis meniuSi, arsebobs ramodenime sxva
brZaneba iseve, rogorc gamoxazvis meniuSi
52
Adding the Bridgexidis damateba
From the options menu, select Add a Bridge
and/or Culvert opciebis meniudan SearCieT
daamateT xidi an/da wyalsadeni Add a Bridge
and/or Culvert
53
Adding the Bridgexidis damateba

• This brings up a window with the adjacent
  upstream and downstream cross-sections plotted
• Sedegad gamoCndeba fanjara zedadinebis da
  qvedadinebis ganivi kveTebis damatebiTi naxazebiT

54
Deck/ Roadwayxidis savali nawili/zatkecili

• Next, select the Deck/Roadway button from the
  Bridge data window
• Semdeg SearCieT xidis savali nawili/gzatkecili-s
  Rilaki xidebis monacemTa fanjaraSi

55
Deck/Roadwayxidis savali nawili/gzatkecili
Notice the weir coefficient and max submergence
window are showing the default values aRsaniSnavi
a, rom winaswaraa gansazRvruli jebiris
koeficienti da maqsimaluri CaZirvis koeficienti
56
Deck/Roadwayxidis savali nawili/gzatkecili
Enter the data for the required values. Note
that the U.S. and D.S. sideslopes (SS) are for
cosmetic purposes only SeiyvaneT monacemebi
savaldebulo sidideebis aRsawerad. aRsaniSnavia,
rom z.d da q.d gamoiyeneba mxolod kosmetikuri
funqciisTvis
unless using the WSPRO method for low flow Tu
araa miTiTebuli WSPRO meTodi dabali dinebisTvis
57
Deck/Roadwayxidis savali nawili/gzatkecili
Use the Copy Up to Down button to repeat the
station-high chord-low chord data from the
upstream to the downstream side, if
applicable gamoiyeneT Copy Up to Down
Rilakebi, raTa ganmeorebiT SeviyvanoT
saguSagos-simaRle, savali nawilis qveda
horizontis monacemebi zedadinebidan qveda
dinebisken, im SemTxvevaSi Tu monacemebi
Sesaferisia.
58
Deck/Roadwayxidis savali nawili/gzatkecili
After selecting OK from the bridge deck window,
it replots the U.S. and D.S. x-sections showing
the bridge deck mas Semdeg rac, xidis savali
nawilis fanjaraSi SerCeuli iyo Tanxmobis Rilaki
OK, is asaxavs xidis saval nawils qd da zd
X seqciaSi
59
Deck/Roadwayxidis savali nawili/gzatkecili

• Q What is the extent of the bridge deck on these
  bridges?
• kiTxva ra gavrcoba aqvT saval nawilebs am
  xidebze?

60
Deck/Roadwayxidis savali nawili/gzatkecili

• Q What is the extent of the bridge deck on these
  bridges?
• kiTxva ra gavrcoba aqvT saval nawilebs am
  xidebze?

61
Pierspirsi

• Piers can be added by selecting the Pier button
  from the bridge data window
• pirsis damateba SesaZlebelia, Tu avirCevT pirsis
  Rilaks xidebis monacemebis fanjridan

62
Pierspirsi
This brings up the Pier Data Editor where you can
add the data for the pier(s) es gvaZlevs pirsis
monacemebis redaqtirebis saSualebas, da
SesaZlebelia monacemebis damateba pirsebisTvis
Use the Copy Up to Down button, if
applicable gamoiyeneT Copy Up to Down Rilaki,
Tu saWiroa
63
Pierspirsi
The pier is then shown graphically on the
plot pirsi Semdgom gamoisaxeba grafikulad naxazze
64
Bridge Modeling Approachxidis modelirebis midgoma

• The modeling options, including low flow and high
  flow modeling methods, are available by selecting
  the Bridge Modeling Approach button
• modelirebis opcia, romelic moicavs dabali dinebis
  da maRali dinebis modelirebas xelmisawvdomia Tu
  avirCevT xidis modelirebis midgomis Rilaks

65
Bridge Modeling Approachxidis modelirebis midgoma
This brings up Bridge Modeling Approach Editor
window. Notice the option to compute each type
of low flow method and the option to select which
one you use es gviCvenebs xidis modelirebis
midgomis redaqtoris fanjaras. aRsaniSnavia
parametri, romelic iTvlis dabali dinebis yvela
tipis meTodiT da parametri romelic saSualebas
gvaZlevs avirCioT dinebis tipi
Q Is using highest energy always a good
idea? kiTxva ramdenad gamarTlebulia umaRlesi
energiis gamoyeneba?
66
Bridge Modeling Approachxidis modelirebis midgoma
Orifice Coef. - between 0.7 and 0.9 SesarTavis
koeficienti 0.7 sa da 0.9 s Soris
67
Bridge Modeling Approachxidis modelirebis midgoma
Note the gaiTvaliswineT
68
Bridge Modeling Approachxidis modelirebis midgoma
Click on it to get a table of values daaklikeT,
raTa miiRoT sidideebis cxrili
69
Unique Bridge Problems gansxvavebuli xidis
problemebi

• Debris
• namsxvrevebi
• Parallel Bridges
• paraleluri xidebi
• Bridges on a Skew
• xidebi mosaxvevSi
• Examples
• magaliTebi

70
Debrisnaleqebi

• What about debris?
• naleqebis Sesaxeb
• Check Floating Debris on pier data editor
• SeamowmeT motivtive naleqebi pirsis monacemTa
  editorSi
• Enter rectangular dimensions
• daumateT marTkuTxa mimarTuleba

71
Debrisnamsxvrevebi

• On pier
• pirsze
• Solid
• myari
• Floats
• motivtive

72
Parallel Bridgesparaleluri xidebi

• If very close could be modeled as one, OR two
  linked with 1 Cross Section
• Tu axlosaa erTmaneTTan modelSi Segvyavs, rogorc
  erTi xidi an ganvixilavT, rogorc or, magram erT
  prfilTan dakavSirebul xidad.
• If flow expands between, add sections to model
  transition.
• Tu dineba afarToebs xidebs Soris arsebul sivrces,
  maSin daamateT seqcia Sualeduri gadasvlis
  modelirebisTvis.

Two bridges do not necessarily have twice the loss
73
Bridges on a Skewxidebi da moRunva

• Skew increases pier width decreases bridge
  opening
• moRunva adidebs pirsis siganes da amcirebs xidis
  Ria nawils.
• Bridge skew up to 20o show no additional flow
  problems
• xidis 20 mde gadaRunvis dros Tavs ar iCenen
  damatebiTi probelebi.
• Projected width of bridge based on cosine of skew
  angle
• xidis kosinusis daxris kuTxeze damyarebuli
  proeqcirebuli sigane

74
Use Skew Bridge/Culvert option on bridge/culvert
editormoRunuli xidis/ milebis opciebi xidis/
wyalsadenis editorSi
Warning Review Carefully! gafrTxileba gadaxedeT
yuradRebiT
75
Q What are the modeling issues? kiTxva ra aris
modelirebis daniSnuleba?
76
Q What are the modeling issues? kiTxva ra aris
modelirebis ZiriTadi mizani?
77
Q What aspects of these bridges do you need to
model in HECRAS? kiTxva am xidebis romeli
aspeqtebis gaTvaliswinebaa saWiro modelirebisas?
78
Q What aspects of these bridges do you need to
model in HECRAS? kiTxva am xidebis romeli
aspeqtebis gaTvaliswinebaa saWiro HECRAS Si
modelirebisas?
79
End of lecture leqciis dasasruli