Structural Dynamic Characteristics of Ancient Egyptian Obelisks and Their Responses to Earthquake Loads

Darwish, Mohamed; Rashwan, Mohamed

doi:10.1061/(asce)sc.1943-5576.0000363

Cited by 4 publications

(4 citation statements)

References 8 publications

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“…Another important observation from this study is that even though the analyzed seismic events were smaller than Mw 7.6, the constructed numerical model created using the finite element approach provides reasonable results. In addition, the observed fundamental natural frequency of the Obelisk is consistent with the range of the dominant frequencies of the earthquakes (Tedesco et al, 1999;Darwish and Rashwan, 2018). This suggests that it might be possible that under the seismic event greater than Mb 7.5 expected in the Marmara Region, the Obelisk would be experiencing critical damage due to resonance.…”

Section: Discussionsupporting

confidence: 64%

“…However, the largest modal participation factor, 80% at the seventh mode took place in the z direction. The fundamental natural frequency of the Obelisk is 0.888 Hz, which is consistent with the range of the dominant frequencies of earthquakes (Tedesco et al, 1999;Darwish and Rashwan, 2018). This suggests that under a seismic event greater than Mb 7 expected in the Marmara Region, the Obelisk would be experiencing critical damage due to resonance.…”

Section: Model Analysissupporting

confidence: 74%

“…The Obelisk is a red Aswan granite, resting on four bronze cubes and marble. In the literature, there are a number of studies considering the mechanical properties of obelisks all around the world (Vasconcelos, 2005;Sadan et al, 2007;Arslan, 2016;Darwish and Rashwan, 2018). The material properties of the Obelisk were determined using information inferred from studies given above.…”

Section: Numerical Modelmentioning

confidence: 99%

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Structural Evaluation of an Ancient Egyptian Obelisk in Istanbul

Polat¹

2020

Yerbilimleri/Hacettepe Üniversitesi Yerbilimleri Uygulama Ve Araştırma Merkezi Dergisi

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The "Obelisk of Theodosius" is one of the most important monuments located in the former Hippodrome in Istanbul, Turkey. The Obelisk with its sculpted base is 24.77 meters in height today, but historical recordings indicate that it was evidently higher originally. Additionally, the recordings show that some of the parts were left behind in Egypt due to transportation. The Obelisk has been exposed to many natural devastating events, particularly strong earthquakes. The monument is in a seismically very active region, Istanbul, located near one of the most devastating active faults of Turkey, the North Anatolian Fault. For the preservation of this obelisk, it is important to evaluate its seismic performance. For this purpose, in this study, the structural dynamic characteristics and the response of the obelisk were investigated. To achieve this aim, a numerical model was created using a finite element approach. In addition to this, real ground motion data were analyzed in this study. The most important finding of the study is that although the obelisk had experienced devastating earthquakes for a long time, revealed deformation is not noticeable. Its strength against earthquakes is most likely related to its constructed materials.

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Section: Discussionsupporting

confidence: 64%

Section: Model Analysissupporting

confidence: 74%

Section: Numerical Modelmentioning

confidence: 99%

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Structural Evaluation of an Ancient Egyptian Obelisk in Istanbul

Polat¹

2020

Yerbilimleri/Hacettepe Üniversitesi Yerbilimleri Uygulama Ve Araştırma Merkezi Dergisi

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“…The seismic vulnerability study of the Bengut Lighthouse has been carried out by performing, first, a preliminary modal analysis to assess the dynamic behavior of the structure and the potential damage modes. This analysis is useful to verify the consistency of the assumptions made in terms of material parameters and connections with respect to the general damage modes observed [51,52].…”

Section: Preliminary Modal Analysismentioning

confidence: 96%

Seismic Vulnerability of Masonry Lighthouses: A Study of the Bengut Lighthouse, Dellys, Boumerdès, Algeria

Amari¹,

Foufa²,

Zouaoui³

et al. 2020

Buildings

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In Algeria, lighthouses are an essential element of the maritime landscape and constitute a substantial part of the local historical and cultural heritage, marked by a great variety of styles, architecture, geometrical forms, and materials. The study presented falls into the general context of pre- and post-seismic conservation of Algerian lighthouses, since all these stone masonry buildings are situated in areas characterized by a medium–high seismic hazard. In the paper, a relevant example has been analyzed: the Bengut Lighthouse, which has been classified as “National Heritage” by the Algerian Ministry of Culture and has been severely damaged by the Boumerdès that occurred on 21 May 2003. After an overview of historical lighthouses in Algeria and their morpho-typological classification, the case study of the lighthouse at Cap Bengut is presented, showing the results of a detailed survey of the geometric and constructive features and of the actual cracking and damage pattern. First, based on the critical analysis of this knowledge framework, a preliminary qualitative evaluation of the seismic vulnerability has been made, analyzing and classifying the set of local and global failure modes coherently with the observed structural pathologies and damages. Then, numerical modeling has been implemented in TreMuri computer code, performing a set of pushover analyses. This allowed the investigation of the criticalities in the response of the building to seismic actions, characterization of the dynamic behavior, and comparison with the actual observed damages, which are discussed, providing an interpretation of the global and local failure modes. Based on the results of the visual assessment and numerical analysis, guidelines for the retrofitting intervention have been proposed, by considering, on the one hand, the objective of effectively mitigating the elements of vulnerability pointed out by the results and, on the other, the main principles of conservation and restoration. The presented study and its results, in perspective, are intended to provide a basis for developing risk and vulnerability analysis of typological classes of historical lighthouses at a large scale.

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Aerodynamics of ancient egyptian Obelisks and their structural response to Boundary Layer wind

2022

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Ancient Egyptian obelisks have been carved thousands of years ago and survived many earthquakes and wind storms. This study examines the aerodynamic characteristics and the response of two of the tallest and slenderest ancient Egyptian obelisks to boundary layer winds using a two-phase methodology. The firstphase involved preparing computational fluid dynamics (CFD) models for the twoobelisks with different angles of projection to wind. The variations in the windpressure coefficient and the forces on the obelisks have been studied for differentprojection angles, different reference velocities and along the height of eachobelisk. Within the second phase structural analysis was performed subjecting eachobelisk to a wind load under different angles of loading. The results show that whensubject to boundary layer winds, the pressure coefficient on the surface and thestresses within the obelisks vary significantly with the angle of attack and dimensions of the obelisk.

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Structural Dynamic Characteristics of Ancient Egyptian Obelisks and Their Responses to Earthquake Loads

Cited by 4 publications

References 8 publications

Structural Evaluation of an Ancient Egyptian Obelisk in Istanbul

Structural Evaluation of an Ancient Egyptian Obelisk in Istanbul

Seismic Vulnerability of Masonry Lighthouses: A Study of the Bengut Lighthouse, Dellys, Boumerdès, Algeria

Aerodynamics of ancient egyptian Obelisks and their structural response to Boundary Layer wind

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