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• This paper investigates the form of the Musmeci bridge over the Basento river. • Form-finding and design processes employed and constructive issues are discussed. • Aerial survey using a commercial UAV is used to derive a 3D geometric model. • Force density method with non-isotropic stresses is used to verify the original form. • The found form is verified by r-funicularity. The bridge over the Basento river in Potenza, Italy, designed by Sergio Musmeci, is supported by a continuous double-curvature RC shell optimized to reduce bending forces. This 300 m long bridge can be considered as a unique representative example of pioneering research on the design and construction of optimized structures. First, the design process employed for determining the form of the shell and the relevant constructive issues are described. A refined 3D geometric model of the shell is then obtained through an aerial survey carried out by a commercial UAV and a photogrammetric image-based reconstruction. A recent formulation of the Force Density Method allowing for non-isotropic stress state is exploited to numerically derive the form of the supporting shell; it is validated versus the surveyed geometry of the shell by employing a nonlinear optimization procedure in order to identify forces and stresses to be used as input parameters. Finally, the derived form of the shell is tested by a Finite Element analysis to verify its funicular efficiency, i.e., whether it is capable to withstand design loads by pure membrane actions. [ABSTRACT FROM AUTHOR]

• Use of the Cloud Analysis for the development of probabilistic fire demand models. • The LOCAFI localised fire model was used to model the effect of hydrocarbon pool fires. • Development of fire fragility functions of a steel pipe-rack. • The interstorey drift ratio – average maximum heat flux pair results the most efficient. This paper proposes a new method to build a probabilistic fire demand model (PFDM) to investigate the structural behaviour of a steel pipe-rack located within an industrial installation and exposed to a localised fire. The PFDM will serve to develop fire fragility functions to be used either in a fire risk assessment or in a fully probabilistic structural fire engineering (PSFE) framework. The cloud analysis (CA) was exploited to build a PFDM based on different engineering demand parameters (EDP) – intensity measures (IM) pairs. In particular, the analysis was applied to a prototype steel pipe-rack integrating an industrial plant in Italy. In order to cover a wide range of plausible fire scenarios and to introduce uncertainties in the fire model, 539 fire scenarios were examined by varying the fire diameter, the fire-structure distance and the fuel. The selection of the fire diameters was based on parametric analyses quantifying liquid flow through orifices and pipes. The thermal impact of the pool fires on the structure was analysed using the LOCAFI localised fire model and the thermo-mechanical response of the pipe rack was evaluated by means of finite element analysis. Based on the structural analysis outcomes, it was found that the interstorey drift ratio (ISDR) – maximum average heat flux impinging the structure (HF avg) EDP-IM pair was the most efficient and was also characterised by the highest relative sufficiency among the other pairs. Moreover, it has to be noted that for this type of case study, the CA revealed to be a viable option to build a PFDM. [ABSTRACT FROM AUTHOR]