A parametric study of linear and non-linear passively damped seismic isolation systems for buildings
Author: Cenk Alhan, Henri Gavin | Size: 0.5 MB | Format:PDF | Quality:Unspecified | Publisher: Department of Civil and Environmental Engineering, Duke University, Durham, NC 27708-0287, USA | Year: 2004 | pages: 13
The effects of near-field ground motions with large velocity pulses have motivated passive damping requirements for the protection of seismically isolated structures. Structures in which the first mode damping exceeds 20% or 30% typically do not exhibit classical modes, and simulation via a simple superposition of uncoupled second order equations is not possible. When the damping is produced by viscous or linear visco-elastic devices, we can, however, gain insight into the dynamic behavior of these structures using a convenient first-order formulation and frequency domain methods. When the damping effects are created by nonlinear mechanisms such as yielding or friction, the behavior of the structure is amplitude dependent and analyses are commonly carried out in the time domain. In this paper, frequency domain analysis and earthquake time history analysis are applied to study the influence of isolation damping on higher-mode effects and inter-story drift ratios. Because higher mode effects, plan irregularities, and bi-directional ground motions are all important attributes of the dynamic behavior of these structural systems, a simple comparison of isolation damping mechanisms can not be carried out via simple single or two degree of freedom realizations. In order to incorporate these important details in the study of the dynamic behavior of these structures, a set of 8-story proto-type building models with L-shaped floor plans, different isolation periods, isolation damping characteristics, and levels of isolation stiffnesses are examined.
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Author: Matthew Grey | Size: 4.8 MB | Format:PDF | Quality:Unspecified | Publisher: A thesis submitted for the degree of Master of Science by Research at the University of Oxford | Year: 2006 | pages: 166
Guyed masts are a specialized type of structure commonly used in the broadcasting industry to support equipment at substantial heights. The dynamic analysis of these structures under seismic loading is a much understudied field that requires investigation. The complex nature of their analysis arises from the nonlinear force-deflection relationship of the cable supports as well as P-D effects in the mast. These lead to the structure exhibiting significant nonlinear characteristics even under working load conditions. Full nonlinear analysis of guyed masts is rarely performed as it is complex and time consuming. Masts are usually designed by equivalent static methods for wind and ice loading only, with the seismic load case often assumed to be less onerous. The validity of this assumption is investigated as part of this research.In this project four existing guyed masts in the UK with heights ranging from 99m to 312m are accurately analysed under various seismic loading conditions using SAP2000 structural analysis software. The research aims to gain an understanding into the distribution and magnitudes of forces developed during typical seismic and design wind events, establish indicators and trends that may aid in guyed mast design, and identify the circumstances in which seismic loading may be the governing load case. Investigations into the ‘travelling wave’ effect, the significance of vertical motion, and the suitability of a response spectrum analysis are also undertaken. Applicable sections of Eurocode 8 are followed wherever possible.It is shown that when subjected to substantial seismic events with peak ground accelerations in the region of 4m/s2 , significant forces can develop in masts that are comparable to those
produced during a wind assessment using the Patch Load method. The distribution of forces can be appreciably different from a wind loading analysis and any regions with irregular or inconsistent distribution of wind response forces can be vulnerable to seismic loading, particularly when mean hourly design wind speeds are less than 22m/s. It is also shown that enough common or predictable seismic behaviour exists between masts to suggest that the development of a simplified seismic analysis method for guyed masts is feasible.
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Author: João Luís Domingues Costa | Size: 2.8 MB | Format:PDF | Quality:Unspecified | Publisher: DANMARKS T E K N I S K E UNIVERSITET | Year: 2003 | pages: 101 | ISBN: ISBN 87-7877-129-9
The work has been carried out at the Department of Structural Engineering and Materials, Technical University of Denmark (BYG•DTU) under the supervision of Professor, Dr. techn. M. P. Nielsen.
The author would like to thank his supervisor for giving valuable advice and inspiration as well as valuable criticism to the present work.
Thanks are also due to the author’s co-supervisor M.Sc. Ph.D. Rita Bento, Instituto Superior Técnico, Lisbon, Portugal, who has given important and useful comments and suggestions. A word of appreciation should also be addressed to Civil Engineer Ph D Junying Liu, COWI A/S, for providing the example used in the case study and for assistance in carrying out the study. The Portuguese institution for scientific research Fundação para a Ciência e Tecnologia – FCT, sponsors the Ph.D. project under which this report was done. The author grateful acknowledges this support.
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Would appreciate if someone could post structural drawings/details of typical canopy coverings in gas/petrol stations.
These canopies generally comprise structural steelwork (cols and beams).
Some canopies are free standing (cantilevered) whilst others extend and partially supported by the main building (T shaped canopy).
Thank you in advance.
Indonesian Garuda Steel Section Database (PRO) for import in SAP/ETABS
Size: 4 KB | Format:rar | Quality:Unspecified
This section database are based on Garuda Steel WF Profile that have been common used in Indonesia.
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The 6th Civil Engineering Conference in The Asian Region and Annual HAKI Conference 2013
Author: Asian Civil Engineering Coordinating Council (ACECC) | Size: 178 MB | Format:HTML | Quality:Unspecified | Publisher: Indonesian Society of Civil and Structural Engineering (HAKI) | Year: 2013
PREFACE
The Indonesian Society of Civil and Structural Engineers (HAKI) is pleased to host this 6th Civil Engineering Conference in the Asian Region (6th CECAR). The triennially held CECAR is the main activity of ACECC, the Asian Civil Engineering Coordinating Council. The first CECAR organized by PICE in 1998, the second by JSCE in 2001, the third by KSCE in 2004, the fourth by CICHE in 2007 and the fifth by EA in 2010. This year, the 6th CECAR is held at the same time as the annual HAKI Conference 2013.
The major theme of this conference is "Embracing the Future through Sustainability". The papers and presentations are mainly invited by HAKI and other ACECC member societies, which are also the co-hosts of this event, i.e. ASCE, CICHE, EA, ICE (I), JSCE, KSCE, MACE, PICE and VIFCEA. The technical program starts with the Keynote Addresses by Ir. Djoko Kirmanto, Dipl. H.E., the Minister of Public Works and Dr. Bambang Susantono, the Vice Minister of Transportation. Furthermore, six keynote lectures are given by the renowned representatives from ASCE, CICHE, HAKI, JSCE, and KSCE. There are eight parallel technical session for oral presentations and 24 poster presentations, with a total of more than 200 abstracts and papers included in the conference proceedings. Abstracts are printed in a paper form, while full papers of the proceedings are included in a separate USB.
There are more than ten tracks for the technical sessions. Some of them are
Climate Change,
Sustainable Infrastructure,
Analytical, Design, and Testing Technologies,
Advanced Construction Technologies,
Construction Engineering and Management,
Operation and Maintenance Engineering,
Urban Problems,
Mega Projects, etc.
In addition, six Special Sessions are organized to discuss important issues on
Tsunami - Lessons Learned from Past Disasters,
Disaster Mitigation, Adaptation and Preparedness Strategies,
Long Span Bridges,
Anti Corruption,
Precast Concrete Structures, and
Building Information Management.
Further, five Special forums are arranged by ACECC member institutions to discuss various matters, i.e. (1) Symposium on Asia and Pacific Collaboration of ITS research (JSCE), (2) Workshop on Vulnerability and Resilience of Critical Infrastructure Systems in Asia (ASCE), (3) Forum on Concrete Model Code (KSCE), (4) Presidential Session on Infrastructures (HAKI) and (5) Asian Board Meeting (JSCE). Most of the materials presented in Special Forums are published separately.
I hope that the ideas contained in the proceedings will be helpful, useful and informative to those who have attended this conference so that we can embrace the future through sustainability and have better quality of life in the Asian region.
Lastly, I would like to acknowledge Editorial Board of the 6th CECAR proceedings who have successfully compiled this fine technical volume.
Prof. Iswandi Imran, Ph.D
Chair, Local Organizing Committee of the 6th CECAR
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Article/eBook Full Name: Analysis of beams on BI-moduli elastic foundation
Author(s): Moshe A. Adin, David Z. Yankelevsky, Moshe Eisenberger
Edition: Vol 49, Iss 3
Publish Date: 1985
Published By: Computer Methods in Applied Mechanics and Engineering
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Article/eBook Full Name: Plates and Beams on Elastic Foundations–Linear and Non-Linear Behaviour
Author(s): Y. K. Cheung ; D. K. Nag
Edition: Vol 18, Iss 2
Publish Date: 1968
Published By: Géotechnique
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Article/eBook Full Name: Analysis of elastic beams on nonlinear foundations
Author(s): Fred W. Beaufait, Peter W. Hoadley
Edition: Vol 12, Iss 5
Publish Date: 1980
Published By: Computers & Structures
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Constitutive models are the key-stone not only for understanding the mechanical behaviour of granular materials (mainly soils but also other granulates such as sugar, wheat, coal, pellets) but also for carrying out numerical predictions by means of the finite elements method. However the extreme complexity of the behaviour of granular materials gave rise to confusing multiplicity of hardy tractable constitutive models proposed so far. the present book comprises a selection of the state-of the-art contributions of world-wide leading specialists with the aim to evaluate, specify and re-assess the present achievements as well as to point on needs for future research.
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On the Seismic Vulnerability of Existing Buildings: A Case Study of the City of Basel
Author: Kerstin Langa) and Hugo Bachmann, M.EERI | Size: 0.8 MB | Format:PDF | Quality:Unspecified | Year: may 2011 | pages: 24
In order to assess the seismic risk for Switzerland, and particularly for the city of Basel, the seismic vulnerability of the existing buildings needs to be evaluated. Since no major damaging earthquake has occurred in Switzerland in recent times, vulnerability functions from observed damage patterns are not available. A simple evaluation method based on engineering models of the building structures suitable for the evaluation of a larger number of buildings is therefore proposed. The method is based on a nonlinear static approach acknowledging the importance of the nonlinear deformation capacity of the buildings subjected to seismic action. Eighty-seven residential buildings in a small target area in Basel were evaluated. The results are vulnerability functions that express the expected damage as a function of the spectral displacement. In order to extrapolate the results to other residential areas of the town, building classes were defined for which the vulnerability is presented in a probabilistic form that can be used directly for earthquake scenario projects.
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INFLUENCE OF SOIL CONDITIONS ON BUILDING VULNERABILITY
Author: CERASELA-PANSELUŢA OLARIU ,* , IOANA OLTEANU , YEUDY FELIPE VARGAS and MIHAI BUDESCU | Size: 7.3 MB | Format:PDF | Quality:Unspecified | Publisher: Universitatea Tehnică „Gheorghe Asachi” din Iaşi | Year: may 2011
Seismic risk assessment of structures is one of the key elements in estimating and reducing losses that may appear after earthquakes. Building vulnerability quantifies the damages a structure can handle under a known seismic load. Usually, structures are considered to be fixed at the base in the design process, but researchers have highlighted the importance of considering the actual soil conditions in the analysis. In this paper, a nonlinear static analysis(pushover) is performed in SAP 2000, for a reinforced concrete 2-D frameresting on different types of soils. Comparisons between capacity curves,vulnerability curves and between the failure mechanism have been performed.From these comparisons, it was possible to extract some observations concerningthe soil condition influence upon building vulnerability and seismic risk for a RC frame.
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