Fluid-structure interaction in the safety of infrastructures

The current research work aims at analysis of fluid-structure interaction in hydraulic pipe systems induced by equipment corrosion and differential pressure actions. The extreme importance of this subject is the occurrence of an abnormal accident in a main pipe water drinking system in the Pumping-Station of Telheiras, from Lisbon Water Supply System, which caused pipe displacements and breaks in some supports. This situation occurred after a valve closing, which lead a significant differential pressure in the pipe system. To seek the vulnerability of these hydraulic systems (to different typical loads), many case studies were developed by a water hammer and structural models, having always the base system of the Pumping-Station of Telheiras, where the accident occurred. These analyses were developed in order to show the possible consequences in terms of displacements, when the system is submitted to different loads and type of supports. The study comprises the analysis of the effect of a differential pressure between the two sides of the valve V59 (upstream and downstream), occurred during the accident. The results of the displacements obtained by the simulations were compared to the values measured by experts. It is equally emphasized the importance of integrated analysis (fluid-structure interaction) and the purpose of supports in water pipe systems in the infrastructures design.