SS 1-3: Actions and Interventions upon Existing Structures (fib SAG7)

Robby Caspeele, Ghent University, Ghent, Belgium

Stuart Matthews, BRE (Building Research Establishment), Garston, United Kingdom

Giuseppe Mancini, Politecnico di Torino, Torino, Italy

Robby Caspeele    Stuart Matthews    Giuseppe Mancini    


Current practice on the assessment of existing structures - subject to e.g. deterioration, damage, etc. - lacks thorough evaluation of the safety level. The assessment is often performed on the basis of guidelines which rely on the (subjective) experience of the investigator and the way field or laboratory investigations are incorporated in the safety assessment can be improved. Contradictory to new structures, the required safety level of existing structures is not well defined, so that decision making is less benchmarked by objective criteria.

The overall aim of fib SAG7 is the development of a Model Code for the assessment of present structural performance and the prediction of future structural performance of existing concrete structures with or without damage and/or revised operational requirements, together with any associated interventions required to extend their service life.

Among others, the following topics are covered by this group:
- A proposition of target safety levels for existing concrete structures;
- Structural models and reliability procedures in order to assess the actual structural performance of existing concrete structures, including the incorporation of prior information and field investigations into the assessment procedure;
- Methods for predicting the evolution of the actual structural performance with time;
- Development of decision making techniques for selecting appropriate interventions required to preserve or establish the desired safety level or to extend the service life of the concrete structures that are considered.


Decision making tool for seismic retrofit of existing structures based on marginal productivity and actualized costs of the retrofitting operations
D. Asprone, F. Jalayer, A. Prota, R. Russo

Rehabilitation design methodology for public hospital using seismic monitoring throughout structural life cycle
G. Atanasiu, V. Murarasu

Evaluation of Bayesian updated partial factors for material properties in existing concrete structures
R. Caspeele, L. Taerwe

Verification of older prestressed concrete road bridges according to the German structural assessment provisions
D. Dunkelberg, K. Zilch, M. Hennecke, M. Heinze

Target reliability levels for the assessment of existing structures – Case study
M. Sykora, M. Holicky

Verification of existing reinforced concrete structures using the design value method
M. Sykora, M. Holicky

Load-carrying capacity and refurbishment of a historic RC Vierendeel bridge
P. Van Bogaert

Simulation technique for service life assessment of facade refurbishment
E. Vesikari, R. Ferreira

Girder shear resistance assessment – Applications of SIA 269/2
D. Zwicky