Seismic Safety Enhancement of Structural Systems by Base Isolation and Dynamic Control Techniques

1992 ◽  
pp. 330-344
Keyword(s):  
Base Isolation ◽  
Dynamic Control ◽  
Structural Systems ◽  
Seismic Safety ◽  
Control Techniques ◽  
Safety Enhancement

Laminated Type Isolation Device for Light Weight Structure Using Urethane Elastomer

2017 ◽  
Author(s):  
Kengo Goda ◽  
Osamu Furuya ◽  
Kohei Imamura ◽  
Kenta Ishihana
Keyword(s):  
Seismic Isolation ◽  
Base Isolation ◽  
Light Weight ◽  
Loading Test ◽  
Isolation System ◽  
Seismic Safety ◽  
Base Isolation System ◽  
Weight Structure ◽  
Isolation Device ◽  
Urethane Elastomer

At the present, base isolation system has been recognized by general earthquake resistant technique since the Great Hanshin Earthquake 1995. The seismic isolation will be aggressively applied to not only architectural and civil structures but also various structures, because the effectiveness on seismic safety had been demonstrated again in the Great East Japan Earthquake. In generally, although the base isolation system is divided into laminated rubber bearing type and friction sliding bearing type. In the case of former type, shape factor, maximum or minimum outer shapes and so on are restricted by the material characteristics in visco-elastic material. In general, the isolation structure is used in high damping rubber. However, we pay attention to base isolation using urethane elastomer. Urethane elastomer has excellent elasticity, mechanical strength, abrasion resistance, weather resistance, oil resistance, impact resistance the absorbent, anti-vibration and excellent low-temperature properties. Furthermore, it is possible to impart various characteristics by a combination of isocyanate and polyol and chain extender, requires no large-scale apparatus, it has the advantage molecular design is easy. In previous study, the research and development of laminated type base isolation device using urethane elastomer was carried out to upgrade a seismic safety for various structures. The fundamental characteristics was investigated from several loading test by using various experimental devices, and the design formula for the stiffness and equivalent damping coefficient is formulated as an approximate expression of mechanical characteristics until now. It was confirmed that urethane elastomer is not hardening up to 500% shear strain. Moreover, the experimental examination for aged deterioration in the urethane material has been continuously carried out. As the results, it was confirmed that the laminated type seismic isolation device using urethane elastomer is possible to develop as a practicable device from the stable mechanical properties as considering in design step. In this study, the small-scale laminated type base isolation device using urethane elastomer is advanced to the direction of further technical upgrading and of scale down for light-weight structure as a sever rack. The first stage, basic properties of the urethane elastomer has been investigated by loading test. Furthermore, the design equation is created by loading test using urethane elastomer. The validity of the design equation has been confirmed. The second stage, the compression creep test with laminated type base isolation device has been investigated to confirm an effect on light-weight mechanical devices.

Research and Development of Damping Device for Light Weight Mechanical Structure Using Damping Effect Caused by Eddy Current

2009 ◽  
Author(s):  
Osamu Furuya ◽  
Keiji Ogata ◽  
Toyohiko Tanaka ◽  
Hiroshi Kurabayashi
Keyword(s):  
Eddy Current ◽  
Base Isolation ◽  
Low Cost ◽  
Control Technique ◽  
Small Scale ◽  
Light Weight ◽  
Isolation System ◽  
Seismic Safety ◽  
Damping Effect ◽  
Kobe Earthquake

A base-isolation and vibration control technique has been applied positively to architectural and civil structures after Kobe earthquake, and now the techniques are adopted as general vibration reduction technique for many structures. In such situation, an application of the vibration attenuation device to the small-scale structure has been carried out actively in recent years. Especially, in the important institution of the cities such as a refuge place, a hospital, a school, an information and a communication institution where function maintenance is needed, it is important to maintain its performance of the machinery and equipment in the facility with an upgrade of structural seismic safety. Moreover, in the future, upgrading of seismic safety of the particular equipments is urgent business. This study has been examined a low cost and compact damping device for base-isolation system of light weight mechanical structures like a computer server rack. In this paper, the experimental and analytical results on the basic performances of the damping device using damping effect by Eddy-Current.

Vibration Reduction Mechanism and NPPs Seismic Safety of TMD Shield Building for AP1000 NPPs

2018 ◽  
Author(s):  
Gang Zheng ◽  
Feng Shen ◽  
Yaodong Chen ◽  
Gangling Hou
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Base Isolation ◽  
Influence Factors ◽  
Structural Features ◽  
Base Shear ◽  
Seismic Safety ◽  
Force Transfer ◽  
Reduction Effect ◽  
Optimal Stiffness

Without additional mass, the tuned mass damping (TMD) shield building for AP1000 Nuclear Power Plants (NPPs) was achieved easily by changing the stiffness and damper between parts of shield building. Meanwhile, the new TMD structure combined the structural features of the shield building with TMD technology. The optimal model for the new structure was built and the optimal stiffness and damper of TMD bearing were given on the dynamic characters of the shield building and its parts. The vibration mitigation mechanism and reduction effect were clearly stated by using base shear force transfer function. By comparing with the seismic responses of the traditional model and the base isolation model, the influence factors of the new TMD structure, such as the mechanism of TMD bearing, the gravity liquid tank mass, and the earthquake waves under different sites were studied. The new TMD structure is tested to satisfy the NPPs seismic safety requirements, stable reduction efficiency, anti-seismic robust characteristics and adaptive site.

Passive Control Techniques for Seismic Protection of Chemical Plants

2020 ◽  
Author(s):  
Keisuke Minagawa ◽  
Fabrizio Paolacci
Keyword(s):  
Passive Control ◽  
Base Isolation ◽  
Seismic Damage ◽  
Pressure Vessels ◽  
Chemical Plant ◽  
Seismic Protection ◽  
Economic Losses ◽  
Chemical Plants ◽  
Northridge Earthquake ◽  
Control Techniques

Abstract Seismic damage of chemical plant facilities (pressure vessels, piping, storage tanks, etc..) can causes human and economic losses as well as heavy environmental damages. Therefore, it is of paramount importance to reduce such a consequences. The passive control techniques (PCT) as dampers or base isolation can represent an effective technique to mitigate the major damage caused by earthquakes. Viscous dampers, tuned mass dampers and base isolators are well-known passive control devices successfully applied to civil structures, as demonstrated during the last big events as Northridge earthquake in 1994, the Kobe earthquake in 1995, the Great East Japan earthquake in 2011. The scarce application to major hazard industrial facilities as chemical plants poses some questions, including the selection of suitable devices, their real applicability and effectiveness, because of the strict requirements of chemical plant equipment in terms of safety and business continuity. Therefore, this study aim at analyzing the possible applications of the most renew passive control techniques for seismic protection for chemical plant components. In this respect, a complete review of typical seismic damage of industrial (chemical) facilities and the investigation of the applicability of PCT as mitigation strategy is offered for all possible structural typologies of units presents in a plant.

Passive Seismic Protection of Building Piping Systems — A Review

2020 ◽  
Vol 20 (03) ◽  
pp. 2030001 ◽  
Author(s):  
Jie Tan ◽  
Peng Zhang ◽  
Qian Feng ◽  
Gangbing Song
Keyword(s):  
Base Isolation ◽  
State Of The Art ◽  
The State ◽  
Seismic Protection ◽  
Internal Stresses ◽  
Piping System ◽  
Seismic Safety ◽  
Nonstructural Components ◽  
Piping Systems ◽  
Passive Seismic

Piping systems are typical nonstructural components of a building. Previous investigations have reported many cases that earthquake causes damages or failures of piping system, resulting in secondary disasters. Therefore, this paper conducts a survey of the seismic damage of the piping systems of buildings and then reviews the state-of-the-art of the passive seismic protection methods. This paper proposes to classify the building piping system into rigid connected pipes, flexible connected pipes and semi-rigid connected pipes. Typical seismic damages of building pipes are presented following this classification. Then, several current seismic protection methods (including constructional measures, seismic braces, damping techniques and base isolation methods) are discussed regarding the theoretical mechanism and feasibility. Furthermore, the state-of-the-art of the building piping system and the passive protection methods with application prospects are evaluated. Based on the review, the flexible piping systems are most commonly used in existing old buildings and are more vulnerable in earthquakes due to their high flexibility. New buildings prefer the rigid connections which tend to restrain the motion of the pipe. However, the excessive stiffness of the rigid connection may cause overlarge internal stresses in both the connection and the pipe. Semi-rigid piping systems have sufficient overall stiffness and a degree of local deform ability and thus have the best seismic performance. In future studies, more research should be devoted to propose and develop new dampers suitable for piping systems, which will improve the seismic safety of building piping systems.

Study on Laminated Type Base Isolation Device Using Urethane Erastomer for Practical Application

2015 ◽  
Author(s):  
Kenta Ishihana ◽  
Osamu Furuya ◽  
Kengo Goda ◽  
Shohei Omata
Keyword(s):  
Mechanical Characteristics ◽  
Base Isolation ◽  
Approximate Expression ◽  
Response Analysis ◽  
Loading Test ◽  
Cross Sectional ◽  
Isolation System ◽  
Seismic Safety ◽  
Isolation Device ◽  
Urethane Elastomer

Base isolation system will be aggressively applied to not only architectural and civil structures but also various structures, because the effectiveness on seismic safety had been demonstrated again in the Great East Japan Earthquake. In this study, the research and development of laminated type base isolation device using urethane elastomer has been carried out to upgrade a seismic safety for various structures. The fundamental characteristics have been investigated from several loading test by using various experimental devices, and the design formula for the stiffness and equivalent damping coefficient is formulated as an approximate expression of mechanical characteristics until now. Moreover, the experimental examination for aged deterioration in the urethane material has been continuously carried out. This paper summarizes the mechanical characteristics based on the loading test up to 500% shear strain using experimental specimen with 100×100 mm cross-sectional shape, base isolation effect from time response analysis using nonlinear element model of urethane elastomer and the accelerated aging test for verifying the aging of practical use.

Innovative seismic resistant structure of shield building with base isolation and tuned-mass-damping for AP1000 nuclear power plants

2019 ◽  
Vol 36 (4) ◽  
pp. 1238-1257 ◽  
Author(s):  
Gangling Hou ◽  
Meng Li ◽  
Sun Hai ◽  
Tianshu Song ◽  
Lingshu Wu ◽  
...  
Keyword(s):  
Nuclear Power ◽  
High Performance ◽  
Seismic Isolation ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Base Isolation ◽  
Risk Mitigation ◽  
Design Parameters ◽  
Seismic Safety ◽  
Content Type

Purpose Seismic isolation, as an effective risk mitigation strategy of building/bridge structures, is incorporated into AP1000 nuclear power plants (NPPs) to alleviate the seismic damage that may occur to traditional structures of NPPs during their service. This is to promote the passive safety concept in the structural design of AP1000 NPPs against earthquakes. Design/methodology/approach In conjunction with seismic isolation, tuned-mass-damping (TMD) is integrated into the seismic resistance system of AP1000 NPPs to satisfy the multi-functional purposes. The proposed base-isolation-tuned-mass-damper (BIS-TMD) is studied by comparing the seismic performance of NPPs with four different design configurations (i.e. without BIS, BIS, BIS-TMD and TMD) with the design parameters of the TMD subsystem optimized. Findings Such a new seismic protection system (BIS-TMD) is proved to be promising because the advantages of BIS and TMD can be fully used. The benefits of the new structure include effective energy dissipation (i.e. wide vibration absorption band and a stable damping effect), which results in the high performance of NPPs subject to earthquakes with various intensity levels and spectra features. Originality/value Parametric studies are performed to demonstrate the seismic robustness (e.g. consistent performance against the changing mass of the water in the gravity liquid tank and mechanical properties) which further ensures that seismic safety requirements of NPPs can be satisfied through the use of BIS-TMD.

Performance Evaluation of Product Type Magnetic Damper Using Eddy-Current Damping Effect

2011 ◽  
Author(s):  
Osamu Furuya ◽  
Keiji Ogata
Keyword(s):  
Eddy Current ◽  
Base Isolation ◽  
Low Cost ◽  
Vibration Reduction ◽  
Product Type ◽  
Small Scale ◽  
Isolation System ◽  
Seismic Safety ◽  
Damping Effect ◽  
Kobe Earthquake

Response control techniques such as a base-isolation and a vibration control have been a general vibration reduction system for upgrading of seismic safety or habitability improvement in civil and architectural structure after Kobe earthquake. In such state in Japan, an application of the vibration reduction device to a small-scale structure has been carried out actively in recent years. Especially, in the important institution of the cities such as refuge place, hospital, school, information and communication institution where function maintenance is needed, it is important to maintain its performance of the machinery and equipment in the facility with an upgrade of structural seismic safety. Moreover, in the future, upgrading of seismic safety of the particular equipments is urgent business. This study has been examined a compact and low cost damping device for a base-isolation system of light weight mechanical structures like a computer server rack. In this paper, experimental and analytical results on the performances of the product type damping device using damping effect caused by Eddy-Current are described.

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