Improving transportation investment decisions through life cycle cost analysis : comparative LCCA of bridges

• Main Author: Ditrani, Marco
• Format: Bachelor Thesis
• Language: English
• Published: 2009
• Subjects: Technology; Life Cycel Cost Analysis (LCCA); Bridges; Reinforced; Concrete; Timber; Glulam; Soil-steel flexible arch bridges; Teknik; Northern Sweden
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-49945

The aim and scope of the project is to study and apply Life Cycle Cost Analysis (LCCA) to standard bridges with a length of ca 20 m. Eleven bridges of reinforced concrete in northern Sweden have been studied with data from BaTMan, a Swedish bridge data base. Two alternative designs with timber (Glulam) and soil-steel (SuperCor) have also been studied. The concept of Present Value Method, Annuity Cost, and Societal Costs are described and the importance is discussed of parameters such as inflation and interest rates. In the analysis the following choices were made: interest rate 4 % and inflation rates for Maintenance, Repair and Rehabilitation (MR&R) 1,5%, for planning and design 2%, for dismantling 3% and for user’s costs 5%. Methods are described for calculating user costs and for performing traffic analysis with a Swedish model called Sampers. Historical data and forecasts are presented. A sensitivity analysis is performed to understand how and how much the parameters involved in the analysis influence the final result. The life cycle costs for the eleven bridges vary between 4 and 20 Mkr and their annuity costs between 7 and 39 kkr. The lower costs refer to bridges with low initial investment (2,5 Mkr) and low traffic (20 vehicles/day), whereas the higher costs refer to bridges with high initial investment (11 Mkr) and high traffic (5000 vehicles/day). Of the life cycle costs, initial investments are 45 – 84%, user costs are 0,6 – 47%, maintenance, repair and rehabilitation (MR&R) are 4 – 14 %, dismantling are 1,4 – 5,6% and planning and design costs are 0,7 – 3,8%. Bridge designs with timber and soil-steel (SuperCor) are presented based on information collected from producers. LCCA has then been performed for three scenarios with different traffic volumes (100, 500 and 5000 vehicles per day in 2009), which reflect the situation in different Swedish regions. The estimated life cycle costs for the three scenarios are 2,3 Mkr, 2,4 Mkr and 4,4 Mkr for the soil-steel bridges and 2,5 Mkr, 2,7 Mkr and 4,7 ...