Abstract

This paper presents a new service life database (DUREE database) for building elements, based on international service life data. The database includes 7‘000 service life data, for more than 2‘000 building elements. In addition, the fitting of the data to a lognormal distribution is presented. The study contributes to the increasing demand of probabilistic building LCA and LCC and provides the possibility to define statistical distributions, with a systematic way, for a large number of building elements and different levels of details (LOD), appropriate for BIM-based assessments.

Abstract

methodology for cost optimal reliability based inspection and replacement planning of piping subjected to CO2 corrosion is described. Both initial (design phase) and in-service planning are dealt with. The methodology is based on the application of methods for structural reliability analysis within the framework of Bayesian decision theory. The planning problem is formulated as an optimization problem where the expected lifetime costs are minimized with a constraint on the minimum acceptable reliability level. The optimization parameters are the number of inspections in the expected lifetime, the inspection times and methods. In the design phase the nominal design wall thickness is also treated as an optimization parameter. The most important benefits gained through the application of the methodology are consistent evaluation of the consequences of different inspection and replacement plans, consistent incorporation and handling of uncertainties, and consistent updating of inspection and replacement plans based on inspection results. The latter is achieved through application of Bayesian statistics for updating in combination with structural reliability methods. A methodology for cost optimal reliability based inspection and replacement planning of piping subjected to CO2 corrosion is described. Both initial (design phase) and in-service planning are dealt with. The methodology is based on the application of methods for structural reliability analysis within the framework of Bayesian decision theory. The planning problem is formulated as an optimization problem where the expected lifetime costs are minimized with a constraint on the minimum acceptable reliability level. The optimization parameters are the number of inspections in the expected lifetime, the inspection times and methods. In the design phase the nominal design wall thickness is also treated as an optimization parameter. The most important benefits gained through the application of the methodology are consistent evaluation of the consequences of different inspection and replacement plans, consistent incorporation and handling of uncertainties, and consistent updating of inspection and replacement plans based on inspection results. The latter is achieved through application of Bayesian statistics for updating in combination with structural reliability methods.

Abstract

Built vernacular heritage embraces buildings that are not designed by specialists, but are part of a process that involves many people over many generations and relies on empirical knowledge. Its value as a key-element for cultural identity is unquestionable. However, precisely due to its empirical and traditional nature, it is often seen as an obsolete and unsafe way of construction, which leads to its progressive abandonment. This lack of proper construction details and poor maintenance increases the seismic vulnerability of the vernacular heritage. There is an evident need for simplified easy-to-use seismic vulnerability assessment methods for vernacular architecture, given the generalized lack of resources that can be normally assigned to its study and preservation. Most of the times, visual inspection will be the only tool available to carry out the assessment. Nevertheless, simplified methods demand a deep understanding of the seismic behavior of vernacular architecture. This is a complex task given the great heterogeneity in the geometrical, structural, construction and material characteristics of vernacular buildings. The present works explores the development of a probabilistic method for the analytical derivation of seismic fragility functions of vernacular buildings considering uncertainty in material parameters and structural characteristics. The procedure followed to investigate the effect of uncertainty and to evaluate the influence of a set of key parameters on the seismic response of vernacular buildings is based on stochastic analysis. In the end, a simplified numerical tool is proposed which can be applied based on visual inspection. The process applied and shown here is considered as an example of application and can be replicated in other contexts. It ultimately intends to extend the applicability and reliability of current seismic vulnerability assessment methods.