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1

Effect of setback irregularity location on the performance of RC building frames under seismic excitation

Mouhine Mohamed, Hilali Elmokhtar

Archives of Civil Engineering

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2020

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Vol. 66, nr 4

399--412

EN

The setback is a frequent type of irregularity expected in complex-shaped buildings. The main purpose of the present paper is to emphasize the influence of setback location on the performance of reinforced concrete building structures under seismic excitation. In this research study, 68 building models with setback values vary from 0.1 L to 0.5 L, located at various levels, are studied. Non-linear static (pushover) analyses were conducted. All building models are analyzed using a finite element calculation code. The outcomes show that setback irregularity location has a significant effect on the seismic behavior of the structure. Based on the regression analysis of the results obtained in the current study, a mathematical formula is proposed to quantify the effect of setback location on the performance of building structures. The results of this study would aid all professionals in the building sector to anticipate the response of these types of structures during the design phase.

2

The response of three colliding models of steel towers to seismic excitation

Sołtysik B., Jankowski R.

Czasopismo Techniczne. Budownictwo

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2016

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Y. 113, iss. 3-B

123--131

EN

A number of past and recent observations have confirmed that collisions between adjacent, insufficiently-separated structures occurring as a result of seismic excitation (structural pounding) may result in serious damage to structural elements and can even lead to their total destruction. This paper summarises the results obtained from a shaking table experimental study which investigated structural pounding between three adjacent models of steel towers. The study included different configurations of towers and distances between the structures. The results of the study confirmed that collisions have a significant influence upon the behaviour of the towers, leading to the increase as well as decrease in the structural response.

PL

Wielokrotne obserwacje potwierdzają, iż zderzenia podczas trzęsień ziemi pomiędzy zbyt blisko sąsiadującymi ze sobą budynkami mogą powodować znaczące zniszczenia elementów konstrukcyjnych, a czasem mogą nawet prowadzić do całkowitego zniszczenia konstrukcji. Niniejszy artykuł przedstawia wyniki badań eksperymentalnych przeprowadzonych na stole sejsmicznym dotyczących odpowiedzi zderzających się trzech modeli stalowych wież. W analizie tej uwzględniono różne ustawienie konstrukcji oraz zmieniającą się odległość pomiędzy nimi. Wyniki badań potwierdzają, iż interakcje pomiędzy konstrukcjami mają znaczący wpływ na zachowanie się wież, prowadząc zarówno do wzrostu, jak i redukcji odpowiedzi.

3

Experimental and numerical investigation of rotational friction dampers with multi units in steel frames subjected to lateral excitation

Mirzabagheri S., Sanati M., Aghakouchak A. A., Khadem S. E.

Archives of Civil and Mechanical Engineering

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2015

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Vol. 15, no. 2

479--491

EN

Performance of rotational friction dampers with two and three units was evaluated experimentally because of a lack of research data on performance of these dampers with multi units. Results of multi-unit dampers were compared with the results of one-unit damper. Increasing trend in dissipating energy was observed. Then, the behavior of these dampers in frames of 3, 7 and 12 stories was studied by modeling the damper directly. Nonlinear time history dynamic analysis was used. It was observed that by increasing the number of stories in the buildings, dampers with multi units should be used to perform properly against earthquake. The equivalent damping method was also investigated to consider the effects of this damper without direct modeling of the damper. Effective damping of the frames equipped with this type of damper was estimated and used in nonlinear time history dynamic analysis and it was observed that the responses of these structures with dampers can be approximated by the responses of moment resisting frames without damper but with damping equal to the effective damping due to rotational friction damper.

4

O projektowaniu obiektów budowlanych poddanych wpływom sejsmicznym według Eurokodu 8

Zembaty Z.

Inżynieria i Budownictwo

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2010

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R. 66, nr 10

539-544

PL

Omówiono treść Eurokodu 8 dotyczącego projektowania obiektów budowlanych na terenach sejsmicznych. Zwrócono szczególną uwagę na definicje obciążeń sejsmicznych, sposoby obliczania sił sejsmicznych oraz odpowiednie kształtowanie układów konstrukcyjnych. Przytoczono definicje obszarów niskiej i bardzo niskiej sejsmiczności oraz podano aktualne propozycje stref sejsmicznych na terenie Czech.

EN

The paper presents in a concise form the content of Eurocode 8 dealing with the design of structures for earthquake resistance. Particular attention was paid to the definitions of seismic loads, calculation of seismic forces shaping of structural systems. The definitions of areas of low and very low seismicity were given as well as proposals for the seismic zones on the territory of Czech Republic.

5

Shear band formation behind retaining structures subjected to seismic excitation

Green R. A., Michalowski R. L.

Foundations of Civil and Environmental Engineering

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2006

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No. 7

157-169

EN

The behaviour of soil retaining structures during earthquakes is investigated. Seismic excitation imparts inertial forces to the soil retaining system, and, once the seismic acceleration reaches the yield level, the structure exhibits permanent displacements. This is typically associated with appearance of a shear band in the backfill. The application of the kinematic approach of limit analysis is briefly discussed. A specific example of a retaining wall with one distinct shear band is then presented. The inclination of the shear band is found to be dependent on the acceleration amplitude of the seismic excitation, per classical earth pressure theory. Also, it was found that the inclination of the shear band docs not remain stationary, but rather changes throughout the shaking in response to the variation in the acceleration amplitude of the excitation. This phenomenon is illustrated by results from both a physical experiment and a numerical prediction, which indicate a distinct change in the shear band inclination during seismic excitation, leaving a clear pattern of "shear banding".