The N2 method has been extended in order to take into account higher mode effects in elevation. The extension is based on the assumption that the structure remains in the elastic range when vibrating in higher modes. The seismic demand can be obtained by enveloping the results of basic pushover analysis and the results of standard elastic modal analysis. The results obtained for test buildings show that a considerable influence of higher modes on storey drifts is present at the upper part of medium- and high-rise structures.
COBISS.SI-ID: 4725601
The predictions obtained by using different empirical ground-motion prediction equations differ considerably. In the paper, a non-parametric approach, called the CAE (Conditional Average Estimator) method, has been used for prediction. The comparison between the CAE results and the predictions obtained by other models suggest that the model predictions depend substantially on the selection of the effective database and on the adopted functional form. The non-parametric CAE method has proved to be a simple but powerful tool for ground-motion prediction, especially in a research environment.
COBISS.SI-ID: 5013857
The stiffness of rubber bearings typically increases during weak earthquakes. This can reduce the efficiency of the isolation. To improve the response of isolators in the case of lower seismic intensities, a new isolation device, which adjusts itself to the intensity of the load, has been developed. It is made from a magnetically controlled elastomer (MCE), i.e. a rubber-like material whose stiffness can be varied by applying a magnetic field. The efficiency of this new device was evaluated. Appropriate numerical models of the device and the control algorithm have been developed.
COBISS.SI-ID: 4994145
Analytical, closed-form solutions are derived for the computation of equivalent constant rates of limit state exceedance for structures under seismic loads whose capacity is degrading with time. The solutions are formulated both in the demand-based and in the intensity-based format, the latter being suitable for all limit-states, even close to global collapse. By using a 7-story reinforced concrete building as an example, we demonstrate the accuracy and the practicality of these approximations for the assessment of an existing structure.
COBISS.SI-ID: 5018465
Estimating the performance of structural elements requires the assessment of their response in terms of their response values (e.g. strength, stress, drift, cracks). The paper provides an overview of some of the methods for the evaluation of the in-plane resistance of masonry walls. Some results of recent experimental investigations of the shear capacity of in-plane loaded masonry walls subjected to cyclic loading are also presented with the aim of studying the potential for the application of these new concepts for assessment of seismic performance.
COBISS.SI-ID: 4963169