Laboratory and field tests for a realistic assessment of the shear capacity of existing prestressed concrete bridges

摘要

Due to increasing traffic loads and a constant updating of the design requirements on the resistance side, a recalculation of existing concrete bridges according to current standards often results in calculatory structural deficits, especially with regard to a sufficient shear capacity. Whereas allowing of reserves in the bearing capacity is reasonable for the design of new structures and usually leads to moderate additional costs, this often produces costly rehabilitation measures and traffic obstruction for building redevelopment. Therefore realistic design approaches and models both for the load and resistance side have a significant importance for the recalculation and assessment of existing bridge constructions. This paper initially gives an overview of verifications for the redesign of bridges, then discusses special demands and certain influences for the formulation of realistic design models for the shear resistance and finally presents current experimental investigations in the laboratory and in-situ on real bridge structures.