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Davorin Kolić "Optimization of Bridges for Big ... - neuronconsult.eu

Neuron Zagreb dooDavorin KolićOptimization tion of Bridges forBig Crossings5th CCCBaden ,September 25,2009


Contents :• 1. Introduction• 2. Limits of „feasible span lenghts“• 3. Bridge systems for big crossings• 4. Optimization method• 5. Example from practice• 6. Conclusionstr. 2/ 28


1. IntroductionNeed for a big crossing :• Traffic requirements• Strategical reasons• Economical reasonsLake Pontchartrain Causeway Bridgeover lake near New Orleansa, USALength 38 km, with 4 lanes on 2 parallelbridges, pile foundation 6 m long, inconstruction 1955/56 i 1967/69Traffic development: 3000 veh./day (1956)3000 veh. / ho (1990)Structural types :• 1 bridge type in a row• system of bridges• hybrid type with bridges,tunnels and islandsstr. 3/ 28


1. IntroductionLongest bridge crossings : one bridge type, bridge system or hybrid crossings bridgeisland-tunnel.str. 4/ 28


1. IntroductionLongest planned bridge crossings as : bridge systems or hybrid bridge-island-tunneltype.str. 5/ 28


1. IntroductionHangzhou BayBridge 35.6 kmQatar-BahrainCauseway45 kmstr. 6/ 28


2. Limits of „feasible span lenghts“The need for optimization of big bride crossingProject phases included in optimization :Konačni iznos troškovaEstimation of possible cost overrun 10-25 % 10-200 %Used project budget 2 - 10 % 90-98 %Criterium for the most feasible solution :* economical feasibility (lowest price)At the end of construction => required budget size is known ( planned budget +unexpected costs )str. 7/ 28


2. Limits of „feasible span lenghts“Saul R. (2003) : “Aesthetics vs. Economics...”, BarcelonaDistribution of limits of feasible span lenghts for different bridge typesaccording to construction price on traffic surface unit.str. 8/ 28


2. Limits of „feasible span lenghts“big crossings less than 2000 mLenghts L < 2000 m :• bridges• Immersed tubesDecision on structuretype:* Ship channel* Geological conditions* Weather condition* Vicinty of towns2. Bridge over Danube Vidin (Bg) – Calafat (Ro)L = rail 2480 m / road bridge 1440 m, Dunube width 1300m, 2rail and 4 road lanes, in constructionstr. 9/ 28


2. Limits of „feasible span lenghts“big crossings from 2000 – 10 000 mLenghts L = 2–10 000 m :• bridges• Immersed tubes• Bored tunnelsmain ship channel2 km 2 km 3.4 kmbridgebridgeImmersed tube, 50m depth8.2 kmBridge Pusan – island Geoje (S.Korea)L = 8.2 km, 4 road lanesWind up to 288km/h, earthquake, sea depth 50 m• KombinationsDecision on structuretype:* Ship channel* Traffic requirements* Geologic conditions* Weather conditions* Location specialitiesstr. 10/ 28


2. Limits of „feasible span lenghts“big crossings longer than 10 000 mLenghts L > 10 000 m :• bridges• Immersed tubes• combinations( No N immersed tubes €!)Fehmarnbelt(Danska–Njemačka)L = 19 km4 road lanes2 rail lanes,wind, sea depth 30 m, tobe constructedDecision on structuretype: :* Ship channel* Traffic requirements* Geologic conditions* Weather conditions* Location specialities* Addit. structures (€!)str. 11/ 28


3. Bridge systems for big crossingsFreasible bridge types for optimal bigcrossing :• Arch wit hbox section in steel andconcrete• Continuous box girders in steel andpresstressed concrete• Suspension bridges in steel(composite)• Cable stayed bridges(steel, concrete, composite,combinations)Su Tong (Kina), over river YangtzeL = 8.15 km, L cbs.= 2088 m, L mid= 1088 m6 road lines, piles 120 m deepMost often bridge combination for big crossing : CBS + continuous girder.str. 12/ 28


3. Bridge systems for big crossingsComparison :Cont.girder andcable stayedbridge upto 2500 mFor loading :* road* railRelation : overall crossing length vs. unit construction price.str. 13/ 28


3. Bridge systems for big crossingsComparison :SuspensionbridgesandCBS +cont.girdersup to 18 000 mRelation of overall crossing lengths and unit construction price.For loading :* road* road + railstr. 14/ 28


3. Bridge systems for big crossingsUnsure feasible studies :• problem of „unhonest numbers“• rough analyses• possibility to manipulateProject budget overruns duringconstruction in traffic infrastructure :• steady phenomena in last 100 years• overruns up to 250 %Intentions :• make project more attractive• animate investors• start with construction asapResults :• phenomena of massive budgetcost - overrunsstr. 15/ 28


4. Optimization methodMethod development :• Considering project developmentphases• Optimization during all phasesOptimization method following :Design phase :Empirical knowledge + numericalanalysisCost calcualtion :Empirical knowledge + costs,numericalConstruction :Empirical knowledge + cost control,numerical evaluationstr. 16/ 28


4. Optimization methodModul F A U S TOptimization module :Multicriterial analysis wit hqualitativeand quantitative partQualitative analysis :Method PPA („Potential-Problem-Analysis“) ebvaluation of negativescenarios of unexpected happeningsQuantitative analysis :Numerical cost analysis of values ofnegative scenarios of unexpectedhappeningsstr. 17/ 28


1. Design phase :• Basic solution• Overview of dimensions and structuralsolutions• Comparison with results of NA and othersimilar projects• Changes, improvements6. Optimization• What is missing ?• Negative scenarios of unexpected items• Evaluation of negative scenario• Decision on change1. Design phase :• change of structural detail• improvements and additions4. Optimization methodQualitative Analysisstr. 18/ 28


4. Optimization methodQualitative Analysis – Register R1str. 19/ 28


4. Optimization methodQualitative Analysis – Register R1str. 20/ 28


4. Optimization methodQualitative AnalysisCathegorization matrixLevels of influence andrequired actionstr. 21/ 28


4. Optimization methodQuantitative AnalysisNumerical evaluation of negativescenarios in economical way :Evaluation of still-stands and coststhat are caused(based on the still–stand duration) :U i= V i* P i* C i“U i” – overall cost“V i” - possibility“P i” - influence“C i” – cost of a scenariostr. 22/ 28


4. Optimization methodQuantitative AnalysisdC i= n * V i* min/max (Cd i+ Cv i)str. 23/ 28


4. Optimization methodQuantitative Analysisstr. 24/ 28


5. Example from practiceBridge over Golden Horn in Vladivostok, L = 329,98 +737+ 321.94 = 1388.92mstr. 25/ 28


5. Example from practiceBridge over Golden Horn in Vladivostok, L = 329,98 +737+ 321.94 = 1388.92mstr. 26/ 28


str. 27/ 28


6. ConclusionCost calculation during differentproject development phases:• analyses based on structural projectcapacityOptimization :• structural and economical feasibilityto be evaluted• Optimization method to minimize andcotrol the project budgetFinancing types :• Private financiog or hybrid financingmodelsProject development :• Concessions :• BOT – build-operate-transfer, etc.• DBOT, DBOT, DBOM, or other PPPtypesstr. 28/ 28

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