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Analiza zmienności odpowiedzi konstrukcji w kontekście akcelerogramów dobieranych do uśrednionych spektrów odpowiedzi

Bąk Michał

Przegląd Budowlany

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2019

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R. 90, nr 9

19--27

PL

Ocena metod wyboru akcelerogramów jako danych wstępnych podczas analiz time-history skupia się obecnie na odpowiedniej reprezentacji warunków sejsmicznych lokalizacji. Jednym z czynników, który może być brany pod uwagę podczas selekcji akcelerogramów może być rozproszenie wyników analizy konstrukcji. W niniejszym artykule autor rozważa konstrukcję stalową, badaną uprzednio w publikacjach [2, 3, 4, 5, 6], na podstawie 12 różnych parametrów użytych podczas wyboru rzeczywistych wymuszeń kinematycznych, jako danych wstępnych do analizy time-history.

EN

Assessment of accelerogram selection methods, as preliminary data during the time-history analyses, currently focuses on adequate representation of seismic conditions of location [1]. One of the factors which can be taken into account during the selection may be scattering of results of constructional analysis. In this article, the author examines a steel construction, previously tested in publications [2, 3, 4, 5, 6], based on 12 different parameters used during selection of actual kinematic excitations, as preliminary data for the time-history analysis.

2

An algorithm developed in Matlab for the automatic selection of cut-off frequencies, in the correction of strong motion data

Sakkas G., Sakellariou N.

Acta Geophysica

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2018

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Vol. 66, no. 4

425--448

EN

Strong motion recordings are the key in many earthquake engineering applications and are also fundamental for seismic design. The present study focuses on the automated correction of accelerograms, analog and digital. The main feature of the proposed algorithm is the automatic selection for the cut-off frequencies based on a minimum spectral value in a predefined frequency bandwidth, instead of the typical signal-to-noise approach. The algorithm follows the basic steps of the correction procedure (instrument correction, baseline correction and appropriate filtering). Besides the corrected time histories, Peak Ground Acceleration, Peak Ground Velocity, Peak Ground Displacement values and the corrected Fourier Spectra are also calculated as well as the response spectra. The algorithm is written in Matlab environment, is fast enough and can be used for batch processing or in real-time applications. In addition, the possibility to also perform a signal-tonoise ratio is added as well as to perform causal or acausal filtering. The algorithm has been tested in six significant earthquakes (Kozani-Grevena 1995, Aigio 1995, Athens 1999, Lefkada 2003 and Kefalonia 2014) of the Greek territory with analog and digital accelerograms.

3

Evaluating main parameters effects of near-field earthquakes on the behavior of concrete structures with moment frame system

Jouneghani K. T., Hosseini M., Rohanimanesh M. S., Dehkordi M. R.

Advances in Science and Technology. Research Journal

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2017

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Vol. 11, no 3

10--23

EN

Amplitude and frequency content are two important features of earthquakes that are different for near and far-fault earthquakes and in most of the standards, the effects of near-field earthquakes in loading are not considered. Therefore, study and comparison of these effects on structures is necessary. In this paper, structural operation against near and far fault earthquakes for two near sites and two far sites is investigated. For this purpose and in order to achieve an operation point of a structural model with six staircases with a mean lateral bending frame resistant system seismic hazard information is analyzed with regards to special plan spectrums of 2 different sites using near and far faults. An evaluation of the effects due to near and far fault earthquakes based on the Iran’s standard 2800 ranges on operation point and the comparison of operation effects of near and far fault spectrums with Iran’s standard are results of this research work. After the presentation of results obtained from time history analyses, some suggestions are proposed for design correction based on the regulations in near -field earthquakes. Keywords: Near-field earthquakes, moment frames, affect, behavior, Accelerogram compatibility with structural mechanism spectrum.

4

The Effect of the Vertical Acceleration on Stability Assessment of Seismically Loaded Earth Dams

Korzec A.

Archives of Hydro-Engineering and Environmental Mechanics

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2016

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Vol. 63, nr 2-3

101--120

EN

In the assessment of slope stability, the vertical component of acceleration is commonly neglected. However, signal analyses performed on a large number of acceleration time histories have revealed that the vertical peak ground acceleration can be as high as the horizontal one. In this paper, a method of slope stability analysis regarding the vertical component of acceleration is proposed. It considers a rigid body system affected by the acceleration time histories in both horizontal and vertical directions. In a general case, the strength of the contact between acceleration components is time dependent. Parametric analysis was performed on the basis of cyclic harmonic loading, assuming a safety criterion in the form of permanent displacement. The results, for both harmonic and real acceleration time histories, were compared with the results of the commonly used Newmark’s sliding block approach, which revealed significant differences in permanent displacements calculated by the two methods.

5

Acceleration generating corresponding to the proposed response spectra

Dupal J.

Modelowanie Inżynierskie

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2012

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T. 14, nr 45

39--44

EN

Nuclear devices are checked also from the seismic safety point of view. The response spectra method is one of the most important approaches to obtain an upper estimation of some output variables like displacements, velocities, accelerations, stresses etc. The proposed response spectra of the base especially accelerations serves as an input for extreme estimations of mentioned output quantities depending on frequency [1]. The alternative approach for functionality assessment can be used the base acceleration as an input for time integration of the mathematical model and the output quantities can be obtained in the direct integration way of the model. The main requirement on the input acceleration is posed on the desired response spectrum satisfaction. The paper deals with an approach to generation of the base acceleration in such a way to be satisfied the properties of the proposed prescribed response spectrum of the acceleration.

CS

Bezpečnost jaderných zařízení je kontrolována mimo jiné také ze seizmického hlediska. Metoda spekter odezvy patří mezi nejdůležitější metody pro určení horního odhadu výstupních veličin, za které považujeme posuvy, rychlosti, zrychlení, napětí atd. Presentovaný přístup pro posouzení funkčnosti využívá zrychlení základu odpovídající návrhovému spektru odezvy jako kinematické buzení matematického modelu a výstupní veličiny lze získat přímou integrací.