Assessment and maintenance of bridges

Bridges should be designed, constructed and operated in such a way that they fulfil requirements from the fields of function, economy, environment, society, and culture. The present thesis wants to contribute to this matter by illuminating the manifold requirements and by developing a practicable approach to multi-objective maintenance planning for bridges. Starting with a literature review and a survey on practical maintenance planning in Hamburg (Germany) and Chennai (India), the investigation reveals that until today practical approaches for the identification of bridge specific requirements as well as for strategy assessment and evaluation are not at hand. Instead of accounting for the whole range of performance aspects, current investigations are commonly confined to functional and economic aspects or apply monetary transformation, which inevitably causes a distorted perception of reality. As a solution to this, the present thesis develops a practical approach to multi-objective maintenance planning. At the core of the approach is the newly invented SAMS program, which allows for simulation based assessment of maintenance strategies. It applies Monte Carlo simulation and accounts for the interdependencies between structure, deterioration, and maintenance effects. The program is effectively combined with a method for multi-objective strategy evaluation. In addition to this, a newly developed questionnaire for identifying bridge specific requirements is applied. The results from an experimental application to two case study bridges show that suitable strategies for fulfilling the specific requirements could be identified. It was also found that the bridge specific context decisively influences the extent, to which strategies can play out their specific strengths.