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LCC Methodology

LCC Methodology. Håkan Sundquist Structural Design and Bridges KTH. There are many requirements on a bridge. The classic task. The classic bridge design task. LCC optimization. Include maintenance and operation costs. Agency or owner costs.

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LCC Methodology

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  1. LCCMethodology Håkan Sundquist Structural Design and Bridges KTH ETSI Methodology

  2. There are many requirements on a bridge ETSI Methodology

  3. The classic task ETSI Methodology

  4. The classic bridge design task ETSI Methodology

  5. LCC optimization ETSI Methodology

  6. Include maintenance and operation costs ETSI Methodology

  7. Agency or owner costs ETSI Methodology

  8. The bridge must also contribute economically to the society ETSI Methodology

  9. Include society costs during maintenance and repair Include eventual accident costs ETSI Methodology

  10. User benefit and cost ETSI Methodology

  11. Costs for the society due to accidents and total failure • Accidents are usually covered by the society and not by agencies like SRA or FinnRA ETSI Methodology

  12. LCC • Life Cycle Costing LCC is a technique which enables comparative cost assessments to be made over a specified period of time, taking into account all relevant economic factors • initial capital costs • future operational and maintenance costs • owner costs • user costs • society costs • future disposal cost • Used methodology is usually the present value of the total cost of this asset over its lifetime ETSI Methodology

  13. LCC scheme ETSI Methodology

  14. Definitions • LCC owner or agency • LCC = LCCA + LSC + LCCC • LCCA = is the cost for acquisition of the project (design, construction…) by the net present value calculated to a specified time usually the opening of the bridge • LSC = (Life Support Cost) is the cost for future operation, maintenance and repair of the bridge, by the net present value calculated to a specified time usually the opening of the bridge. • LCCC = (Life Cycle Cost Consequence), is the future costs for eventual negative consequences, by the net present value calculated to a specified time, usually the opening of the bridge. ETSI Methodology

  15. LSC, the Life Support Cost • LSC = CI + CN • CI = is the investment in the necessary equipment and other resources for the future operation and maintenance • CN is the future cost for operation, maintenance and repair, by the net present value calculated to a specified time, usually the opening of the bridge • The investment part of the maintenance, CI, could be divided in parts ETSI Methodology

  16. CI = Investment for operation and maintenance • CI = CIr + CIv + CId + CIt • CIr = spare parts and material • CIv = instrument, tools, vehicles that is needed for inspection and maintenance • CId = documentation i.e. drawings and instruction manuals needed for inspection and maintenance • CIt = education of personnel for operation and maintenance ETSI Methodology

  17. The costs are recalculated to one point in time usually the day of opening the bridge • Ct the sum of all costs incurred at time t, • p the real interest rate or a rate taking into account changes in the benefit of the structure and • t is the time period studied, typically for a structure for the infrastructure the expected life span. ETSI Methodology

  18. pc increase of usefulness of the bridge i.e. increase of traffic Interest rate pL interest rate for loans with long duration pi inflation ETSI Methodology

  19. Net present cost for a cost of value=1,0 year 0 ETSI Methodology

  20. User cost delay L length of affected roadway vr the traffic speed during bridge work activity vn the normal traffic speed ADTt the average daily traffic, i.e. cars per day at time t Nt the number of days of road work at time t rL the amount of commercial traffic wL is the hourly time value for commercial traffic wL the hourly time value for drivers T studied time interval T ETSI Methodology

  21. User costs, operation New notations: oL operating cost for the commercial traffic vehicles oG operating cost for transported goods oD operating cost for cars T time interval ETSI Methodology

  22. Societal costs, accidents and failure New notations: An the normal accident rate per vehicle-kilometres Ar the accident rate during roadwork Cacc the cost for each accident for the society Rj probability for a specified failure coupled to KH,j. KH,jcost for failure (One value for ultimate limit state and one for serviceability limit state) For normal bridges the probability of failure is so small that it could be omitted in the analysis! ETSI Methodology

  23. Valuation • Degradation models • Knowledge on interest rents (100 year!!) • Knowledge about the future of the traffic system! (will the traffic increase or decrease??) • Knowledge on costs for • operation, • maintenance, • inspection and • repair ETSI Methodology

  24. “Soft values” must also be included ETSI Methodology

  25. Environmental issues must also be included! AIM of ETSI! ETSI Methodology

  26. Parameters needed for the LCC analysis • Methodologies for dividing the bridge into different parts and giving measures of the components • Costs for construction and repair different parts of the bridge • Yearly operating costs • Actions in time for MR&R actions • Cost for disposal of the bridge • User and societal costs ETSI Methodology

  27. Suggestion for bridge parts ETSI Methodology

  28. Bridge parts and measures ETSI Methodology

  29. Cross-section definitions ETSI Methodology

  30. Foundation ETSI Methodology

  31. Materials for LCC OBS, LCA requires added material definitions! ETSI Methodology

  32. Costs • Cost parameters should be given by the agencies hopefully in data bases updated every year!? • Costs for construction • Cost for MR&R actions • Parameters for calculating the user costs • Societal costs • … ETSI Methodology

  33. Definition of actions • Management • Operation • Inspections • Repair • Upgrading • Final demolition and disposal ETSI Methodology

  34. Operation • Management is the owners own work for keeping the bridge inventory, the planning and other actions to manage the bridge stock. Usually this work can be assigned as percentage of the actual value to re-build the bridge stock. • Operation is the yearly work to superficially and regularly inspect, clean, repair small damages of the bridges. The Swedish term is “Drift” ETSI Methodology

  35. Examples of operation (yearly) actions Examples of “operation maintenance actions”. In the Swedish system this is called “Egenskaper” or “properties” ETSI Methodology

  36. Time between different MR&R actions • Needed parameters: • Life span • Yearly operation actions • Time interval between inspections • Time between maintenance and repair ETSI Methodology

  37. Methods for judging time between MR&R actions • Mechanistic or chemical models • Evaluation results from large field observations, • The up to day most applied method is to use experience from specialists, usually people deeply involved with inspection of bridges Research! ETSI Methodology

  38. LCC With everything in hand it is just to calculate the LCC for a bridge or maybe all bridges in a county or for a road network!! ETSI Methodology

  39. GOOD LUCK! Trying and commenting our programs! ETSI Methodology

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