Author: Alireza Sarebanha
Publisher:
ISBN:
Category :
Languages : en
Pages : 241
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Book Description
Seismic isolation can be an effective strategy to protect critical facilities including Nuclear Power Plants (NPPs) from the damaging effects of horizontal earthquake ground shaking. For critical facilities, the isolation system should demonstrate a high-confidence of low-probability of failure at the design level and the load carrying capacities should be maintained under beyond design earthquake shaking (BDBE). Experimental evaluation of seismic isolation bearings is important to fully understand their behavior and capacity for reliable performance. Safety mechanisms such as a stop can be imposed to prevent excessive displacement of the isolation system under BDBE, however, this raises concerns for detrimental effects of pounding against a stop or moat wall. Methods of analysis are presented in this dissertation to evaluate both seismic isolation system behavior under extreme earthquakes and the potential effects of pounding by imposing displacement restraints. The dynamic response of an isolated NPP depends on the combined characteristics of the ground motion, bearings, and structure while the seismic isolation bearings themselves can exhibit complex nonlinear behavior that depends on several factors, including the scale size, axial load, temperature, and rate of loading especially under strong earthquake shaking. With a specific interest on the in-structure response of seismically isolated NPPs, hybrid simulation is shown to be a viable approach to examine bearing behavior at full scale under realistic earthquake loading. The adaptation of a full-scale bearing test machine (SRMD testing facility at UC San Diego) and developed toolsets for the implementation of fast hybrid simulation to study the dynamic response of base isolated NPP using full scale lead plug rubber bearings under realistic earthquake loading conditions are presented. Results from these tests validate the effectiveness of seismic isolation technology for application in nuclear facilities and provide valuable data towards improving numerical models of seismic isolation bearings. In a seismically isolated NPP, a surrounding moat wall can function as a stop to limit isolation system displacements and prevent bearing failure for beyond design basis shaking. Impact of isolated structures against a moat wall is of concern due to potential amplification of superstructure response. A moat wall model able to capture impact forces is proposed and used in numerical simulations to capture the effects of impact on the response of seismically isolated NPPs. Variable clearance to the stop and a range of properties for the impact model, moat wall and isolation system are considered to identify parameters that influence the response. Results indicate that large NPP plants as considered here can have significant penetration into the moat wall, not fully limiting displacements in the isolation system, while causing considerable increases in accelerations throughout the NPP. A simplified methodology to estimate impact response parameters including penetration is proposed towards developing design tools that consider these effects.
Author: Aikaterini Mousteraki
Publisher:
ISBN:
Category :
Languages : en
Pages :
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Book Description
"Seismic isolation is an effective system to protect structural and non-structural components of high-importance structures, such as hospitals, that need to remain functional in the aftermath of earthquakes. Under extreme earthquakes though, the design displacement of the isolation systems might be exceeded; hence impacts against surrounding moat walls and/or adjacent buildings could be generated. During recent earthquakes, pounding phenomena have caused structural damage or even collapse of civil infrastructure.This thesis evaluates the performance of a nine-storey, steel moment resisting frame (MRF) hospital, which is retrofitted by means of seismic isolation. Triple Pendulum Bearings are employed including the potential for poundings. The hospital is a 1960s Type 2 Construction; thus, it has been characterized as the Canadian Seismic Research Network (CSRN) Benchmark Steel MRF Hospital Structure. The base-isolated building is subjected to a set of 40 ground motions that are selected to represent the seismic hazard in a high-seismicity region in Vancouver. The retrofitted configuration is modeled on an open source nonlinear building simulation platform. The numerical modeling and the impact modeling approach are both validated through the comparison with prior numerical and experimental results. This thesis is concerned with the amplification on the superstructure's dynamic response with the presence of poundings, which implies a potential reduction of the effectiveness of the implemented seismic retrofit system. Highly increased acceleration values that affect the building's non-structural components are recorded through nonlinear response history analyses. It is concluded that the selection of the available gap displacement between the hospital under concern and the surrounding moat walls, should take into consideration two parameters; the design displacement of the isolators and the displacement generated from the nonlinear response history analyses that minimizes pounding effects. A gap displacement between the building and the surrounding moat walls is recommended for limiting impact phenomena. This thesis provides valuable insights into the increase of the effectiveness and reliability of isolation systems in Canada during strong earthquake motions, when poundings are present." --
Author: Wei Song
Publisher: Frontiers Media SA
ISBN: 2889663809
Category : Technology & Engineering
Languages : en
Pages : 213
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Book Description
Author: Boominathan Adimoolam
Publisher: Springer
ISBN: 9811305625
Category : Science
Languages : en
Pages : 268
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Book Description
This book gathers selected proceedings of the annual conference of the Indian Geotechnical Society, and covers various aspects of soil dynamics and earthquake geotechnical engineering. The book includes a wide range of studies on seismic response of dams, foundation-soil systems, natural and man-made slopes, reinforced-earth walls, base isolation systems and so on, especially focusing on the soil dynamics and case studies from the Indian subcontinent. The book also includes chapters addressing related issues such as landslide risk assessments, liquefaction mitigation, dynamic analysis of mechanized tunneling, and advanced seismic soil-structure-interaction analysis. Given its breadth of coverage, the book offers a useful guide for researchers and practicing civil engineers alike.
Author: T W Duerig
Publisher: Butterworth-Heinemann
ISBN: 1483144755
Category : Technology & Engineering
Languages : en
Pages : 512
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Book Description
Engineering Aspects of Shape Memory Alloys provides an understanding of shape memory by defining terms, properties, and applications. It includes tutorials, overviews, and specific design examples—all written with the intention of minimizing the science and maximizing the engineering aspects. Although the individual chapters have been written by many different authors, each one of the best in their fields, the overall tone and intent of the book is not that of a proceedings, but that of a textbook. The book consists of five parts. Part I deals with the mechanism of shape memory and the alloys that exhibit the effect. It also defines many essential terms that will be used in later parts. Part II deals primarily with constrained recovery, but to some extent with free recovery. There is an introductory paper which defines terms and principles, then several specific examples of products based on constrained recovery. Both Parts III and IV deal with actuators. Part III introduces engineering principles while Part IV presents several of the specific examples. Finally, Part V deals with superelasticity, with an introductory paper and then several specific examples of product engineering.
Author: Francesco Silvestri
Publisher: CRC Press
ISBN: 0429632010
Category : Technology & Engineering
Languages : en
Pages : 8083
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Book Description
Earthquake Geotechnical Engineering for Protection and Development of Environment and Constructions contains invited, keynote and theme lectures and regular papers presented at the 7th International Conference on Earthquake Geotechnical Engineering (Rome, Italy, 17-20 June 2019. The contributions deal with recent developments and advancements as well as case histories, field monitoring, experimental characterization, physical and analytical modelling, and applications related to the variety of environmental phenomena induced by earthquakes in soils and their effects on engineered systems interacting with them. The book is divided in the sections below: Invited papers Keynote papers Theme lectures Special Session on Large Scale Testing Special Session on Liquefact Projects Special Session on Lessons learned from recent earthquakes Special Session on the Central Italy earthquake Regular papers Earthquake Geotechnical Engineering for Protection and Development of Environment and Constructions provides a significant up-to-date collection of recent experiences and developments, and aims at engineers, geologists and seismologists, consultants, public and private contractors, local national and international authorities, and to all those involved in research and practice related to Earthquake Geotechnical Engineering.
Author:
Publisher:
ISBN:
Category : Mechanics, Applied
Languages : en
Pages : 620
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Book Description
Author: U.S. Nuclear Regulatory Commission
Publisher:
ISBN:
Category : Nuclear energy
Languages : en
Pages : 48
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Book Description
Author:
Publisher: AASHTO
ISBN: 1560514566
Category : Technology & Engineering
Languages : en
Pages : 63
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Book Description
This edition is based on the work of NCHRP project 20-7, task 262 and updates the 2nd (1999) edition -- P. ix.
Author: Robert Jankowski
Publisher: Springer
ISBN: 3319163248
Category : Science
Languages : en
Pages : 168
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Book Description
This books analyzes different approaches to modeling earthquake-induced structural pounding and shows the results of the studies on collisions between buildings and between bridge segments during ground motions. Aspects related to the mitigation of pounding effects as well as the design of structures prone to pounding are also discussed. Earthquake-induced structural pounding between insufficiently separated buildings, and between bridge segments, has been repeatedly observed during ground motions. The reports after earthquakes indicate that it may result in limited local damage in the case of moderate seismic events, or in considerable destruction or even the collapse of colliding structures during severe ground motions. Pounding in buildings is usually caused by the differences in dynamic properties between structures, which make them vibrate out-of-phase under seismic excitation. In contrast, in the case of longer bridge structures, it is more often the seismic wave propagation effect that induces collisions between superstructure segments during earthquakes.
