New Seismic Isolation Systems for Floating Houses

2012 ◽  
Author(s):  
C. S. Tsai ◽  
H. C. Su ◽  
W. C. Liao ◽  
Yan-Ming Wang
Keyword(s):  
Climate Change ◽  
Seismic Isolation ◽  
Base Isolation ◽  
Isolation System ◽  
Sea Levels ◽  
Earthquake Resistant ◽  
Earthquake Resistant Structures ◽  
Base Isolation System ◽  
Isolation Systems ◽  
Seismic Isolation Systems

Inhabitable land has been decreasing due to the continual rise in sea levels caused by global warming. In response to this climate change, we need to consider looking for living spaces on water surfaces as well as building earthquake-resistant structures, particularly in flood and earthquake prone areas. This paper presents an experimental study on a new base isolation system in mitigating the response of a floating house that is located in a port. Experimental results show that the seismic response of the floating house was considerably reduced by the proposed isolation system with a proper displacement limit.

Investigation of Seismic Isolated Technology in Steel Structure Residence

2011 ◽  
Vol 94-96 ◽  
pp. 710-717
Author(s):  
Feng Hua Zhao ◽  
Jun Yang
Keyword(s):  
Life Cycle Cost ◽  
Seismic Isolation ◽  
Base Isolation ◽  
Nonlinear Dynamic Analysis ◽  
Steel Structure ◽  
Steel Structures ◽  
Hysteretic Model ◽  
Isolation System ◽  
Earthquake Resistant ◽  
Base Isolation System

This paper briefly expounds the basic principle of structure isolation, reviews the development process of isolated technology. Adopting the common and base isolation system and inputting El-Centro as the earthquake wave, in this paper, comparative analysis of structure’s earthquake-resistant performance was conducted on a 6-layer custom steel structure residence in Changzhou area. The result shows that the gradually matured seismic isolated technology can be applied to steel structure as well, which means the seismic isolation steel structures possess the same characteristics as other seismic isolation structures. With the satisfaction of required bearing capacity, the structural reaction to earthquake has been effectively reduced and its safety has been guaranteed after considering the seismic isolation of steel structure residence; moreover, the storey accelerations reaction has also been greatly declined, meeting higher requirements towards comfortableness of residence structure. Meanwhile, by nonlinear dynamic analysis of simple Bouc-Wen hysteretic model, the requirement towards the biggest ductility was discussed and a brief analysis of the life cycle cost of this residence was worked out. The analysis result demonstrates that the seismic isolation layer has effectively controlled the vibration of superstructure, which would contribute to the reduction of seismic hazard.

Hysteresis Loops of Base Isolation System - An Overview

2021 ◽  
Vol 879 ◽  
pp. 189-201
Author(s):  
M.A. Amir ◽  
N.H. Hamid
Keyword(s):  
Earthquake Engineering ◽  
Structural Damage ◽  
Base Isolation ◽  
Numerical Models ◽  
Hysteresis Loops ◽  
Human Beings ◽  
Rc Buildings ◽  
Isolation System ◽  
Base Isolation System ◽  
Isolation Systems

Recently, there are a lot of technological developments in the earthquake engineering field to reduce structural damage and one of them is a base isolation system. The base isolation system is one of the best technologies for the safety of human beings and properties under earthquake excitations. The aim of this paper is to review previous research works on simulation of base isolation systems for RC buildings and their efficiency in the safety of these buildings. Base isolation decouples superstructure from substructure to avoid transmission of seismic energy to the superstructure of RC buildings. The most effective way to assess the base isolation system for RC building under different earthquake excitations is by conducting experiment work that consumes more time and money. Many researchers had studied the behavior of base isolation system for structure through modeling the behavior of the base isolation in which base isolator is modeled through numerical models and validated through experimental works. Previous researches on the modeling of base isolation systems of structures had shown similar outcomes as the experimental work. These studies indicate that base isolation is an effective technology in immunization of structures against earthquakes.

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.

Seismic Analysis and Comparison of Different Base Isolation Systems for a Multi-Storey RC Building with Irregularities in Plan

2012 ◽  
Vol 594-597 ◽  
pp. 1788-1799 ◽  
Author(s):  
Donato Cancellara ◽  
Fabio de Angelis
Keyword(s):  
Base Isolation ◽  
Seismic Analysis ◽  
Cyclic Behavior ◽  
Isolation System ◽  
High Damping Rubber Bearings ◽  
Fixed Base ◽  
Base Isolation System ◽  
High Damping Rubber ◽  
Isolation Systems ◽  
Rubber Bearings

In the present paper the dynamic nonlinear analysis for a 3D base isolated structure is illustrated. A base isolated reinforced concrete building is designed and verified according to the European seismic codes such that the superstructure remains almost completely elastic and the nonlinear elements are localized only in the base isolation system. Nonlinear hysteretic models have been adopted to reproduce the cyclic behavior of the isolators. Two different base isolation systems are considered and their performances are compared for evaluating the behaviour of a base isolated building, highly irregular in plan, in presence of a seismic excitation defined with recorded accelerograms which characterize the bi-directional ground motions. The isolation system has been realized with a combination in parallel of elastomeric bearings and sliding devices. In the first analyzed isolation system we have used the High Damping Rubber Bearings (HDRB) and in the second analyzed isolation system we have used the Lead Rubber Bearings (LRB). Finally a comparative analysis between the base isolated structure with hybrid base isolation systems and the conventional fixed base structure is detailed.

Three Dimensional Seismic Isolation System for Next-Generation Nuclear Power Plant With Rolling Seal Type Air Spring and Hydraulic Rocking Suppression System

2005 ◽  
Author(s):  
Takahiro Shimada ◽  
Junji Suhara ◽  
Kazuhiko Inoue
Keyword(s):  
Dynamic Loading ◽  
Nuclear Power ◽  
Seismic Isolation ◽  
Base Isolation ◽  
Three Dimensional ◽  
Loading Test ◽  
Isolation System ◽  
Ability Test ◽  
Base Isolation System ◽  
Suppression System

Three dimensional (3D) seismic isolation devices have been developed to use for the base isolation system of the heavy building like a nuclear reactor building. The developed seismic isolation system is composed of rolling seal type air springs and the hydraulic type springs with rocking suppression system for vertical base isolation device. In horizontal direction, the same laminated rubber bearings are used as horizontal isolation device for these systems. The performances and the applicability have already been evaluated by the technical feasibility tests and performance tests for each system. In this study, it was evaluated that the performance of the 3D base isolation system with rolling seal type air springs combined with hydraulic rocking suppression devices. A 1/7 scaled model of the 3D base isolation devices were manufactured and some performance test were executed for each device. For the rolling seal type air springs, dynamic loading test was executed with a vibration table, and pressure resistant ability test was executed for reinforced air springs. In the dynamic loading test, it is confirmed that the natural period and damping performance were verified. In the pressure resistant ability test, it is confirmed that the air springs had sufficient strength. For the hydraulic rocking suppression system, forced dynamic loading test was carried out in order to measure the frictional and oil flow resistance force on each cylinder. And the vibration table tests were carried out with supported weight of 228 MN in order to evaluate and to confirm the horizontal and vertical isolation performance, rocking suppression performance, and the applicability of the this seismic isolation system as the combined system. 4 rolling seal type air springs and 4 hydraulic load-carrying cylinders with rocking suppression devices supported the weight. As a result, the proposed system was verified that it could be applied to the actual nuclear power plant building to be target.

A study on seismic isolation of building used LRB

2020 ◽  
Vol 6 (2) ◽  
pp. 52
Author(s):  
Muhammet Yurdakul ◽  
Mehmet Burak Yıldız
Keyword(s):  
Seismic Isolation ◽  
Base Isolation ◽  
Dynamic Loads ◽  
Isolation System ◽  
Rubber Bearing ◽  
Lead Rubber Bearing ◽  
Earthquake Design ◽  
Base Isolation System ◽  
Internal Forces ◽  
Storey Building

Base isolation system with lead rubber bearing (LRB) is commonly used to prevent structure against to damage of earthquake. Design of LRB system is detailed in this study. The isolated building with LRB design according to Uniform Building Code (UBC-97) and fixed building were examined. The six-storey building with LRB and fixed building were modelled in SAP2000 with the same dynamic loads. The relative floor displacement and internal forces of the seismic isolated and fixed building are compared. In addition, transverse and longitudinal reinforcement of any axis of seismic isolated and fixed building are compared. Analyse results showed that effectiveness of using seismic isolation system on building. The weight of longitudinal and transverse reinforcement of isolated building is smaller than fixed building about 36%, 40% respectively.

Development of an Evaluation Method for Seismic Isolation Systems of Nuclear Power Facilities: Part 3 — Seismic Response of Crossover Piping for Seismic Isolation System

2014 ◽  
Author(s):  
Akihito Otani ◽  
Teruyoshi Otoyo ◽  
Hideo Hirai ◽  
Hirohide Iiizumi ◽  
Hiroshi Shimizu ◽  
...  
Keyword(s):  
Seismic Response ◽  
Nuclear Power ◽  
Seismic Isolation ◽  
Evaluation Method ◽  
Response Spectrum ◽  
Time History ◽  
Response Analysis ◽  
Isolation System ◽  
Isolation Systems ◽  
Seismic Isolation Systems

This paper, which is part of the series entitled “Development of an Evaluation Method for Seismic Isolation Systems of Nuclear Power Facilities”, shows the linear seismic response of crossover piping installed in a seismically isolated plant. The crossover piping, supported by both isolated and non-isolated buildings, deforms with large relative displacement between the two buildings and the seismic response of the crossover piping is caused by two different seismic excitations from the buildings. A flexible and robust structure is needed for the high-pressure crossover piping. In this study, shaking tests on a 1/10 scale piping model and FEM analyses were performed to investigate the seismic response of the crossover piping which was excited and deformed by two different seismic motions under isolated and non-isolated conditions. Specifically, as linear response analysis of the crossover piping, modal time-history analysis and response spectrum analysis with multiple excitations were carried out and the applicability of the analyses was confirmed. Moreover, the seismic response of actual crossover piping was estimated and the feasibility was evaluated.

Development of an Evaluation Method for Seismic Isolation Systems of Nuclear Power Facilities: Part 4 — Failure Behavior of Crossover Piping for Seismic Isolation System

2014 ◽  
Author(s):  
Teruyoshi Otoyo ◽  
Akihito Otani ◽  
Shunsuke Fukushima ◽  
Masakazu Jimbo ◽  
Tomofumi Yamamoto ◽  
...  
Keyword(s):  
Nuclear Power ◽  
Seismic Isolation ◽  
Evaluation Method ◽  
Low Cycle Fatigue ◽  
Response Analysis ◽  
Failure Behavior ◽  
Isolation System ◽  
Isolation Systems ◽  
Seismic Isolation Systems ◽  
Failure Location

This paper provides a part of the series titled “Development of an Evaluation Method for Seismic Isolation Systems of Nuclear Power Facilities”. This part shows the failure behavior of crossover piping installed in a seismic isolated plant. The considered crossover piping is supported on one side by an isolated building and by a non-isolated building on the other side. During an earthquake, the piping structure is deformed due to the large relative displacements between the two buildings and at the same time excited by the different building seismic responses. Therefore, the high-pressure crossover piping structure requires both flexibility and strength. In this study, 1/10 scaled shaking tests and FEM analyses have been performed to investigate the failure behavior of the crossover piping, where both seismic motions and excitations have been taken into account. It was confirmed that the failure occurs at the piping elbow through low cycle fatigue. Moreover, the results of the elastic-plastic response analysis, which simulates an extreme level of excitation corresponding to more than three times the design level, are in good agreement with the test results. The simulation also succeeded in predicting the experimental failure location.

scholarly journals Seismic Base Isolation System using Scrap Old Tyres

2020 ◽  
Vol 5 (3) ◽  
pp. 85-90
Keyword(s):  
Seismic Isolation ◽  
Structural Engineering ◽  
Base Isolation ◽  
Shock Propagation ◽  
Analysis Tool ◽  
Element Analysis ◽  
Isolation System ◽  
Isolation Technique ◽  
Base Isolation System ◽  
Seismic Vibrations

Enfeebling the effects of vibration caused by the movement of tectonic plates has been the major topic of research in the field of Structural Engineering. Base isolation is a technique used to counteract the effects of seismic vibration and ensuring the safety of the superstructure. Even though, the strategy of base isolation has been used in interminable number of structures, there is a need for economized, effective base isolation technique. India has been recycling and reusing waste tyres for four decades, it is estimated that 60% are disposed of through illegal dumping. India, being the second largest manufacturer of rubber after China, there is a menace of rubber disposal in the country. Despite the numerous efforts of technologists of recycling and utilizing the scrap rubber tyres, 17% of the scrap rubber tyres are diverted to landfill creating disposal problem. Therefore, there is a need for utilizing the used scrap rubber tyres in an innovative way instead of dumping it. Scrap Rubber tyres, being elastic in nature serve to be a potential shock absorber of seismic vibrations. In the present study, an attempt is made to utilize the recycled scrap rubber tyre in seismic isolation of structure. This technique proves to be a low- cost earthquake mitigation technique which can potentially reduce the damage caused by seismic shock propagation into the structure and hence ensure overall safety of the structure. An experimental analysis is done to evaluate the properties of assembly of rubber tyres and utilization of the same for isolating base of structures to check for the effectiveness in enfeebling the shocks produced by seismic vibrations. Furthermore, using the properties of scrap rubber tyres obtained from the experimental results, performance of the scrap tyres as a base isolation system for a multistoried building and stability of the structure was studied using Finite element analysis tool.

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