Volume 12 (2016): Issue 3 (September 2016)

This article presents a comparative study of the values of hydrodynamic pressure and their resultants occurred during the seismic action using P100-1/2013 technical rules and the relations defined in the papers: [1], [3], [5] and the Romanian standard [2] SR EN 1998-4 (silos, tanks and pipelines), which is implemented in Romania. Two cylindrical tanks placed in the same seismic zone have been chosen, with the same amount of storage (about 5000 m³), but of different geometries, to illustrate the influence of hydrodynamic pressures on the construction size (long and short wall behavior) as a function of ratio of the fluid height on the cylinder radius and ratio of corner period on the eigenperiod of the fluid mass. Also in the analyses, in order to evaluate the hydrodynamic convective pressure both the fundamental period of oscillation of the fluid mass and the first ten periods of oscillation were used.

The explosion of bombs near buildings generally yields severe damages to the structures. Explosion resistant standards and requirements are constantly being developed and upgraded. This paper focuses on the damages which occur toa RC slab due to blast action. The numerical model replicates a ¼ scale experiment. The analysis is conducted using a software based on the recently developed Applied Element Method. This numerical method is able to model accurately all the structural behavior stages up to failure. The results are compared to experimental data available in the literature. The analysis reveals that the slab failure due to uplift pressures may be avoided by some simple reinforcing details, as they are listed in the Romanian National Annex – accidental loads of the Eurocode EN 1991-1-7.

The paper will focus on multi-hazard assessment following the failure of the Ezer dam on Jijia river. All induced risks are analyzed in terms of critical infrastructure protection, considering three possible failure scenarios.

The challenge of these scenarios is to consider the possible effects (continue effects, domino effect, cascading effects) induced by a single hazard, but which may cause one or more sequential hazards. In all three possible failure scenarios it was considered that the bottom gates are not operational, being blocked. The upper boundary condition in the model is the flood with the maximum discharge 0.1%.

This area chosen for analysis is economically underdeveloped. The protective measures are quite low and the exposure generated by accidents at the hydraulic structures or by the extreme weather conditions is quite high either for the existing economic context or for the future investments in those areas.

The implementation by the decision makers of measures for reducing the risk or the multiple risks cannot be done at regional level if all the vulnerabilities in the area are not widely known.

This paper presents an analytical study which deals with the behavior of the circular plates in bending theory, considering the soil-structure interaction under Winkler's hypothesis. It was intended to illustrate the variation of internal forces and deformations according to the flexibility coefficient of plates considering three models: a fixed solid circular plate subjected to a uniformly distributed load, a fixed solid circular plate acted by a displacement applied on the exterior contour and a solid plate subjected to a temperature gradient. For this study the computation relations were written as a product between a dimensional and a non-dimensional factor, the last one indicating the variation of internal forces and deformations. For each type of action there are presented results obtained using the finite element method to illustrate the differences between this method and the analytical computation.