Welcome to RASOR

The main objective of the RASOR project is to develop a systematic PBEE methodology for the seismic risk mitigation of industrial equipment structures, focused on the most important structures of a typical industrial facility: liquid storage tanks, industrial pressure vessels, industrial piping systems and their supports. This objective will be achieved through a multi-disciplinary approach which combines Civil and Mechanical Engineering with Earthquake Engineering, Engineering Seismology, Computational and Stochastic Mechanics, in a effort to produce an integrated seismic risk analysis framework, tailored to the specific characteristics and particularities of industrial installation structures, such as their geometry, high pressure and temperature, operational requirements, material aging and corrosive effects. Of particular importance are the increased safety requirements due the explosive or toxic content of such facilities.

Other critical parameters to be considered are the following: (i) The presence of contained liquid with free surface (in tanks and vessels), which causes liquid-structure interaction and generates additional hydrodynamic loads. (ii) The presence of high pressure and the ensuing danger of fracture and loss of content, mainly in pressure vessels and piping.(iii) The use of steel plates of relatively small thickness, which may lead to local buckling or “wrinkling”. (iv) The sensitivity to initial imperfections that may reduce significantly the capacity of liquid storage tanks against elephant’s foot or sloshing buckling. (v) The large variation of pressure and temperature operational loads in pressure vessels and piping components may lead to accumulation of plastic strains, material degradation or ratcheting, and eventually failure due to fracture, when combined with strong cyclic loading due to earthquake. (vi) The consideration of the surface waves of the ground motion, particularly when they have similar frequency to industrial equipment structures with large eigenperiods compared to civil engineering structures, is very important. (viii) The effect of asynchronous ground motion on structures with large footprints (long piping systems or very broad tanks).