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The objective of this research is to investigate the seismic performance of typical confined masonry (CM) walls under acidic atmospheric environment and to then present a hysteretic model precise, which is capable of simulating seismic performance of CM walls under acid corrosion. Hence, quasi-static tests of six CM walls were performed, which were corroded by artificial climate accelerated corrosion testing techniques. By obtaining the damage process and characteristics, the influence of different corrosion cycles on displacement-load hysteretic curve, skeleton curve, stiffness degradation and energy dissipation capacity were extensively studied. Moreover, the degradation law of specimen mechanical properties were also obtained. The cycle degradation indices was proposed based on energy dissipation, which were used to characterize the degradation law of specimen mechanical properties. Subsequently, the hysteretic model of CM walls was established, where the specific hysteretic rule was also obtained. The results demonstrated that the ultimate bearing capacity, initial stiffness and energy dissipation capacity of the specimen could all gradually decrease with the increase in the number of corrosion cycles, where the decay rate of the stiffness would gradually increase. The proposed hysteretic model can desirably reflect the hysteretic characteristics of CM walls with reversed loading in an acidic atmospheric environment.

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This study concerns the mechanical response of an innovative energy dissipation device. Using this device, beam–column frames can be easily and safely strengthened at many predefined levels according to the seismic load demands of technical standards. The energy dissipation mechanism of the superimposed blades functions via both steel yielding and frictional forces between the blades. The streghtening level can easily be adjusted by the appropriate selection of the number and dimensions of the superimposed blades, their elastoplastic properties, as well as the friction coefficient at their interface. The device was fabricated and investigated both analytically and experimentally under cyclic loading conditions. The analytical model was based on an analytical hysteresis model. The obtained results describe the overall mechanical behavior of the device.

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The paper presents a simple methodology for estimation of the response modification factor (R-Factor) in Puzzle Building Frame (PBF). Meanwhile, brief introduction about the mentioned system (PBF) is presented. R-Factor is one of the seismic design parameters that has a great impact on the reduction of applied base shear forces during powerful earthquakes. The base shear, which is determined by the elastic strength demand that divided by a seismic force modification factor R, is the general method in seismic design codes. This factor reflects the influence of the elastic–plastic deformation and energy-dissipating capacity on the seismic force. Precise determination of response modification factor has a large effect on the consumed steel of structure and finally on total cost of the project. R-Factor depends on several parameters such as Strength, Ductility, Damping and Redundancy, which are the most important parameters. According to this issue, the results show that the value of response modification factor in puzzle building frame is more than the other R-Factors in similar steel structure frames. The results of numerical analysis matched well with pushover analysis by sap2000, one of the powerful structural finite element software. As a result, the estimated value of R-Factor in PBF systems is proposed.

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The paper presents a numerical analysis related to the FE simulation on steel storage pallet racks experimentally tested under pushover loads. Reference is made to specimens differing in components, joints and material properties on which full-scale frame and component tests have been executed in the framework of a European research project on the seismic behaviour of industrial storage systems. The prediction of the experimental behaviour has been carried out by means of a refined software for academic use specifically developed for modelling framed systems made of non-symmetric cross-section members. Analysis results are also compared with those deriving from the use of the more traditional FE beam formulation neglecting warping in order to assess the errors often affecting the design activities in manufacturing offices.

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In this paper a multi-level approach proposed by the Italian Guidelines on Cultural Heritage was adopted to assess the seismic safety of an unreinforced masonry building located in Naples (Italy). In particular, the simplified model of the global seismic response at the territorial scale was used for the first level (LV1), while the nonlinear static (pushover) analysis and the equivalent frame modelling with nonlinear structural elements were adopted for the more accurate global assessment level (LV3). Different evaluations of the safety indexes are compared in the framework of the LV1 level, with particular attention to their reliability in representing the main aspects of the seismic capacity of the building, in terms of the prevailing failure mechanism and the detection of the weaker direction. The achieved results were compared with those obtained by LV3 assessment level.

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A new version of the Italian design code for dams has been recently introduced, thus replacing after 30 years the previous code, which was still based on a permissible stress design philosophy. The new code follows a limit state approach, employs independent load and resistance factors and defines the earthquake actions in accordance with the new seismic classification of the Italian territory. It assigns at each point of the country its own specific uniform hazard spectrum. Focusing on the stress verifications of existing large concrete dams, in this paper some of the innovative aspects contained in the new dam code are discussed. Reference is made to two case studies concerning an arch-gravity and a buttress-gravity dam, pointing out the main differences between the current and the previous version of the above-mentioned standards.

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