Friction-based Control System for Seismic Energy Dissipation with Isolated Stories
Author: Charalampos Iliadis Diploma in Civil Engineering Aristotle University o f Thessaloniki, 2010 | Size: 3.7 MB | Format:PDF | Quality:Unspecified | Year: 2011 | pages: 119
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BASE ISOLATION FOR MULTISTOREY BUILDING STRUCTURES
Author: Peng-Hsiang, Charng | Size: 10 MB | Format:PDF | Quality:Unspecified | Publisher: UNIVERSITY OF CANTERBURY CHRISTCHURCH, NEW ZEALAND | Year: 1998 | pages: 311
Recent earthquakes, particularly the 1989 Lorna Prieta [E2] and 1994 Northridge [E3] earthquakes in California, and the 1995 Kobe [Kl] earthquake in Japan, have caused significant
loss of life and severe damage to property. Many aseismic construction designs and technologies
have been developed over the years in attempts to mitigate the effects of earthquakes on buildings and their vulnerable contents. Attenuating the effects of severe ground motions on the buildings and their contents is always one of the most popular topics in the area of civil and structural engineering and attracts the attention of many researchers and engineers around the world. The technique of base isolation has been developed in an attempt to mitigate the effects on buildings and their contents during earthquake attacks and has been proven to be one of the more effective methods for a wide range of seismic design problems on buildings in the past two decades. Seismic isolation consists essentially of the installation of mechanisms which decouple the structures and their contents from potentially damaging earthquake-induced ground motions. This decoupling is achieved by increasing the flexibility 'of the systems, together with providing appropriate damping. Careful studies have been made of structures for which seismic isolation
may find widespread application. This has been found to include common forms of new and existing multistorey building structures.
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The HAM-SAS Seismic Isolation System for the Advanced LIGO Gravitational Wave Interferometers
Author: Alberto Stochino | Size: 7.5 MB | Format:PDF | Quality:Unspecified | Publisher: Università di Pisa Facoltà di Scienze Matematiche Fisiche e Naturali Corso di Laurea Specialistica in Scienze Fisiche Anno Accademico 2006-2007 Tesi di Laurea Specialistica | Year: 2007 | pages: 132
The three LIGO interferometers are full operative and under science run since November 2005. The acquired data are integrated with those obtained by th Virgo experiment within an international cooperation aimed to maximize the e.orts for the detection of gravitational waves.
From 2001 LIGO I is expected to be shut down and the construction and commissioning of Advanced LIGO to start. The objective of the new generation interferometers is a ten times greater sensibility with the purpose to extend of a factor of a thousand the space volume covered and to increase of the same order of magnitude the probability to detect events.
To increase the sensibility in the band below 40 Hertz, the main source of noise that Advanced LIGO have to face is the seismic noise. In this perspective, the SAS group (Seismic Attenuation Systems) of LIGO has developed a class of technologies on which the HAM-SAS system is based. Designed for the seismic isolation of the output mode cleaner optics bench and more in general for all the HAM vacuum chambers of LIGO, HAM-SAS, with little variations, can be extended to the BSC chambers as well. In HAM-SAS the legs of four inverted pendulums form the stage of attenuation of the horizontal degrees of freedom. Four GAS filters are included inside a rigid intermediate structure called Spring Box which is supported by the inverted pendulums and provide for isolation of the vertical degrees of freedom. The geometry is such that the horizontal degrees of freedom and the vertical ones are separate. Each GAS filter carries an LVDT position sensor and an electromagnetic actuator and so also each leg of the inverted pendulums. Eight stepper motors guarantee the DC control of the system.
A prototype of HAM-SAS has been constructed in Italy, at Galli & Morelli and then transferred to Massachusetts Institute of Technology in the US to be tested inside the Y-HAM vacuum chamber of the LIGO LASTI laboratory.
The test at LASTI showed that the vertical and horizontal degrees of freedom are actually uncoupled and can be treated as independent. It was possible to clearly identify the modes of the system and assume these as a basis by which to build a set of virtual position sensors and a set of virtual actuators from the real ones, respect with which the transfer function of the system was diagonal. Inside this modal space the control of the system was considerably simplified and moree.ective. We measured accurate physical plants responses for each degree of freedom and, based on these, designed specific control strategies. For the horizontal degrees of freedom we implemented simple control loops for the conservation of the static position and the damping of the resonances. For the vertical ones, be
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Recommendations for the Design and Construction of Base Isolated Structures
Author: 1 2 3 R.W .G . Blakeie y , A. W . Charleso n , H.C. Hitchcoc k , L . M . M egge t M .J.N . Priestle y b f R.D . S h a r p e6 R.I . S k i n n e r7 | Size: 4.8 MB | Format:PDF | Quality:Unspecified | Publisher: BULLETI N OF THE NEW ZEALAN D NATIONA L SOCIET Y FOR EARTHQUAK E ENGINEERING , VOL. 12, NO. 2 JUN E 1979 | Year: 1979 | pages: 22
The philosophy of base isolation of structures, generally using
flexible mountings and mechanical energy dissipating devices, is reviewed. Applications of the approach to buildings, bridges, nuclear power plants, equipment and structures rocking on their foundations are described. Where possible, recommended code provisions and design rules are given. The characteristics of the mechanical energy dissipating devices developed to date are discussed and material specification provisions presented. The requirements for construction of base isolated structures and for maintenance of the devices are given. Finally, recommendations are made
on matters for future research.
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COMPARISON OF DESIGN SPECIFICATIONS FOR SEISMICALLY ISOLATED BUILDINGS
Author: EMRE ACAR | Size: 1.8 MB | Format:PDF | Quality:Unspecified | Publisher: A THESIS SUBMITTED TO THE GRADUATE SCHOOL OF NATURAL AND APPLIED SCIENCES OF MIDDLE EAST TECHNICAL UNIVERSITY | Year: 2006 | pages: 123
This study presents information on the design procedure of seismic base isolation systems. Analysis of the seismic responses of isolated structures, which is oriented to give a clear understanding of the effect of base isolation on the nature of the structure; and discussion of various isolator types are involved in this work. Seismic isolation consists essentially of the installation of mechanisms, which vdecouple the structure, and its contents, from potentially damaging earthquake induced ground motions. This decoupling is achieved by increasing the horizontal flexibility of the system, together with providing appropriate damping. The isolatorvincreases the natural period of the overall structure and hence decreases itsvacceleration response to earthquake-generated vibrations. This increase in period,
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DEVELOPMENT OF NEW BAS E ISOLATI O N DEVI CES FOR APPLICATION AT REFINERI ES AND PETROCHEMI CAL FACILITI ES
Author: Paul SUMMERS , Paul JACOB , Joaquin MARTI , Guilia BERGAMO , Luis DORFMANN Gabriella CASTELLANO , Alessandro POGGIANT , Dimitris KARABALIS , Heiko SILBE and Stelios TRIANTAFILLOU | Size: 0.42 MB | Format:PDF | Quality:Unspecified | Publisher: 13th World Conference on Earthquake Engineering Vancouver, B.C., Canada August 1-6, 2004 Paper No. 1036
The concept of seismic isolation is not new, but it has not generally been used in heavy industrial settings.
The European project, INDEPTH (Development of INnovative DEvices for Seismic Protection of
PeTrocHemical Facilities), supported by the Environment and Sustainable Development Programme of
the European Commission Research Directorate General (Contract EVG1-CT-2002-00065), has, as its
objective, the development of new base isolation devices, suitable for application at refineries, LNG and
petrochemical facilities beneath critical structures, such as cylindrical tanks and spheres. The intent of isolation to reduce seismic risk and enhance performance reliability, especially for beyondvdesign basis events, since many of these critical facilities are located in areas of high seismicity worldwide.
In conjunction with development of isolation devices, new flexible piping joints will also be developed in order to accommodate increased displacements beneath isolated structures.
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Feasibility Investigation of Superelastic Effect Devices for Seismic Isolation Applications
Author: G. Attanasi, F. Auricchio, and G.L. Fenves | Size: 0.84 MB | Format:PDF | Quality:Unspecified | Year: 2008 | pages: 09
The objective of this work is to investigate the feasibility of a new seismic isolation device concept, in which
the restoring force is given by the superelastic effect of shape memory alloys. Seismic isolation is an option
for passive protection of structure when an earthquake occurs, because it modifies the structural global
response and improves performance. Dynamic responses of proposed innovative SMA isolation system and
of traditional bearing device are compared through dynamic time history analyses. Results show that the
SMA system is effective in reducing force and displacement demands, dissipating the input seismic energy
and limiting the residual displacements.
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Author: George C. Lee and Zach Liang Multidisciplinary Center for Earthquake Engineering Research, University at Buffalo, State University of New York USA | Size: 0.62 MB | Format:PDF | Quality:Unspecified | Year: 37
In earthquake resistance design of structures, two general concepts have been used. The first is to increase the capacity of the structures to resist the earthquake load effects (mostly horizontal forces) or to increase the dynamic stiffness such as the seismic energy dissipation ability by adding damping systems (both devices and/or structural fuses). The second concept includes seismic isolation systems to reduce the input load effects on structures. Obviously, both concepts can be integrated to achieve an optimal design of earthquake resilient structures. This chapter is focused on the principles of seismic isolation. It should be pointed out that from the perspective of the structural response control community, earthquake protective systems are generally classified as passive, active and semi-active systems. The passive control area consists of many different categories such as energy dissipation systems, toned-mass systems and vibration isolation systems. This chapter addresses only the passive, seismic isolation systems [Soong and Dargush, 1997; Takewaki, 2009; Liang et al, 2011] Using seismic isolation devices/systems to control earthquake induced vibration of bridges and buildings is considered to be a relatively matured technology and such devices have been installed in many structures world-wide in recent decades. Design guidelines have been established and they are periodically improved as new information based on research and/or field observations become available during the past 20-30 years [ATC 1995; SEAONC 1986; FEMA 1997; IBC 2000; ECS 2000; AASHTO 2010, ASCE 2007, 2010]. Besides the United States, base isolation technologies are also used in Japan, Italy, New Zealand, China, as well as many other countries and regions. [Naiem and Kelly, 1999; Komodromos, 2000; Christopoulos, C. and Filiatrault 2006] Affiliated with the increased use of seismic isolation systems, there is an increased demand of various isolation devices manufactured by different vendors. This growth of installing seismic isolation devices in earthquake engineering has been following the typical pattern experienced in structural engineering development, which begins from a “statics” platform by gradually modifying the design approach to include the seismic effects based on structural dynamics principles as they develop and new field observations on the responses of real-world structures. The process is typically slow because most studies and laboratory observations have been concentrated on the performances of the devices with scaled-down experiments. Results could not be readily scaled-up for design purposes. At the same time,
there were very limited field data on the actual performances of seismically isolated
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This is drawings of a "Billet Storage" building of "Medium Section Rolling Mill Plant".
I Uploaded Drawings and Analysis files, unfortunately calculation notes is in Persian language thus I did not uploaded it, if you think it is useful I`ll upload it.
Please review and share with others your comments.
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Ensuring reservoir safety into the future. Thomas Telford, London, 2008 Nonlinear seismic assessment of lightly reinforced concrete intake towers
Author: R. SABATINO, Lloyd’s Register, London, UK (formerly KBR Ltd) A.J. CREWE, University of Bristol, UK W.E. DANIELL, University of Bristol, UK C.A. TAYLOR, University of Bristol, UK | Size: 1.8 MB | Format:PDF | Quality:Unspecified | Year: | pages: 14
Published guidance on the seismic analys is of reinforced concrete intake/outlet towers is limited, especiall
y for their nonlinear response, due to limited knowledge on the nonlinear characteristics ofexisting and new towers. Proving the integrity of existing towers is an international problem for dam owners, and an industrial need exists for arational, cost-effective and validated method for their assessment.This paper describes a series of tests aimed at investigating the seismic performance of typically reinforced, non-seismically designed towers.Monotonic and cyclic push-over tests were performed on 1/6th scaled models. The results from the physical tests were used to validate a 3D nonlinear finite element model of the towers, using embedded steel reinforcement and a smeared crack model to simulate crack properties of the concrete material. The dynamic performance of the structures was investigated by developing a simplified single degree of freedom model and performing a number of simulations to obtain fragility curves of the system. This simplified model was capable of simulating the degrading, hysteretic properties of the towers and was used to perform no nlinear time history analyses using a range of parameters. A probabilist ic approach was selected as the basis of the performance evaluation process using fragility analyses as a tool for modelling the uncertainty associated with the parameter selection. Based on the experimental and analytical results, a three-staged assessment procedure for the seismic performance assessment of the towers was proposed.
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