1,721,084 research outputs found
Evaluation of seismic fragility of electrical insulators
No full textThe paper deals with the seismic vulnerability of high voltage electric equipment as a part of a research project financed by the National Group for the Defence against Earthquakes (VIA project). Using a procedure developed in the past by one of the author (EFA, Effective Fragility Analysis), an effective method for the evaluation of the fragility curves of high voltage electric equipment is proposed. On the basis of experimental results carried out at the laboratory of Department of Structures of the University of Roma Tre, the seismic vulnerability of a 380 kV vertical disconnecting switch have been investigated. According to the EFA method, the fragility curves of the equipment have been built using a limited number of numerical analyses. Finally the influence of the significant parameters on its failure probability has been investigated
On the effectiveness of two isolation systems for the seismic protection of elevated tanks
No full textThis paper deals with the effectiveness of two isolation systems for the seismic protection of elevated steel storage tanks. In particular the performance of High Damping Rubber Bearings (HDRB) and Friction Pendulum isolators (FPS) has been analyzed. As case study, an emblematic example of elevated tanks collapsed during the Koaceli Earthquake in 1999 at Habas Pharmaceutics plant in Turkey is considered. A time-history analysis conducted using lumped mass models demonstrates the high demand in terms of base shear required to the support columns and their inevitable collapse due to the insufficient shear strength. A proper design of HDRB and FPS isolator according to the EN1998 and a complete non-linear analysis of the isolated tanks proved the high effectiveness of both isolation systems in reducing the response of the case tank. Actually, the stability conditions imposed by the code and a reduced level of convective base shear obtained with the second isolation typology suggests the use of FPS isolators rather than HDRB device
Prove cicliche per la caratterizzazione meccanica di apparecchiature elettriche ad alta tensione
No full textIndagini sperimentali e modellazione del comportamento ciclico delle pile di un vecchio ponte autostradale in cemento armato
No full text
Studio dell'efficacia di ammortizzatori a cavo metallico per la protezione sismica di apparecchiature elettriche
No full textSeismic Risk Assessment of Non-Structural Components in Hazardous Facilities Through a Novel ANN-Based Technique
No full textSeismic events pose a significant threat to industrial facilities, and the risk assessment of non-structural components (NSCs) within these structures is paramount for ensuring the safety and functionality of critical infrastructure. This paper presents a novel approach utilizing machine learning techniques to enhance the seismic risk assessment of NSCs in industrial facilities. The proposed methodology integrates data from multiple sources, including seismic records, structural characteristics, and NSC vulnerability parameters, to develop predictive models for evaluating the vulnerability and potential damage to non-structural components during seismic events. The study starts from a dataset generated by using a numerical effective model subjected to a set of natural records. The advantages of using an efficient model that manages to be both reliable and computationally efficient are highlighted in this paper. With this in mind, the steps to be followed to create an efficient numerical model are herein illustrated. Subsequently, an artificial neural network machine learning algorithm is adopted for training and evaluation. The latter is used for predicting the likelihood of damage to NSCs based on factors such as the intensity and duration of ground motion, the NSC's location within the structure, and its inherent vulnerability characteristics. Results are compared with traditional methods. The outcomes indicate the effectiveness of machine learning in improving the accuracy and efficiency of seismic risk assessment for NSCs in industrial plant. The research contributes to the field of seismic risk assessment by demonstrating the potential of machine learning combined with an efficient numerical model in providing more accurate and timely predictions for the vulnerability of nonstructural components, thereby aiding in the development of targeted mitigation strategies and emergency response plans. This paper serves as a foundational step towards a data-driven approach to seismic risk assessment for non-structural industrial components, ultimately reducing the economic and human losses associated with seismic events
Optimal passive control of adjacent structures using viscous devices
No full textThis paper investigates the optimal vibration control of two adjacent shear beam structures coupled with horizontally oriented viscous dampers. A design methodology that is valid for two-degrees of freedom models is extended to account for multi degree of freedom structures. The response of the coupled model due to linearly filtered white noise base motions is calculated and the effectiveness of the proposed methodology is validated by performing a parametric study. The optimal response of the structures with different coupling locations along the height and damping coefficients, are considered
Shaking table tests of a base isolated steel liquid storage tank
No full textThe paper deals with the results of shaking table tests upon a steel liquid storage
tank with a 4 m diameter filled with water up to one meter. This thank is a 1:14 scale model of a real big liquid steel storage tank installed in a petrochemical plant. First, the tank has been tested in fixed base configuration simulating the presence of the floating roof as well. Subsequently, the same thank has been seismically protected with two type of isolators: high damping rubber bearings and sliding isolators equipped with elastoplastic dampers. In each configuration the model has been subjected to the same series of tests. The results confirm the negligible influence of the floating roof and the effectiveness of both the isolation systems in order to reduce the pressure on the tank wall, and as well. On the contrary, in the isolated case a light increasing of the vertical oscillations of the floating roof has been found, partially compensated by a significant increasing of the damping, which reduce the number of the free oscillation in the post-earthquake phase
Design of yielding or friction-based dissipative bracings for seismic protection of buildings
No full textThe problems of designing dissipative bracing systems, based on yielding or friction mechanisms, for the seismic protection of buildings, either for new structures or the retrofitting of existing buildings are considered. After introducing a one-degree-of-freedom (one-DOF) model of a building equipped with dissipative bracings, inelastic response spectra, useful for designing the bracings, are considered. The extension of the design methodology to multi-DOF systems is also considered, paying particular attention to the distribution of stiffnesses and strengths within the structure. The results of a broad parametric investigation of simple shear-type models are discusse
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