Brief Introduction of Traditional Seismic Technology and Emerging Isolation Technology

2014 ◽  
Vol 1010-1012 ◽  
pp. 250-253
Author(s):  
Ji Yang Li ◽  
Wen Fang Zhang
Keyword(s):  
Control System ◽  
Seismic Response ◽  
Seismic Isolation ◽  
Passive Control ◽  
Base Isolation ◽  
Seismic Structure ◽  
Natural Period ◽  
Isolation Layer ◽  
Passive Seismic

Seismic can be divided into passive seismic and active seismic. Seismic isolation technology belong to the second type. Base isolation structure is defined by setting the isolation layer between the superstructure and foundation building, to extend the natural period architecture, increasing the damping to reduce structural seismic response. It is a passive control system. Compared with the traditional seismic structure, it mainly through the isolation layer to absorb and dissipate energy, reducing the response to the earthquake.

Shaking Table Test Study on Mid-Story Isolation Structures

2012 ◽  
Vol 446-449 ◽  
pp. 378-381
Author(s):  
Jian Min Jin ◽  
Ping Tan ◽  
Fu Lin Zhou ◽  
Yu Hong Ma ◽  
Chao Yong Shen
Keyword(s):  
Seismic Response ◽  
Seismic Isolation ◽  
Shaking Table Test ◽  
Base Isolation ◽  
Shaking Table ◽  
Natural Period ◽  
Isolation System ◽  
Isolation Layer ◽  
Lead Rubber Bearing ◽  
Complex Structural

Mid-story isolation structure is developing from base isolation structures. As a complex structural system, the work mechanism of base isolation structure is not entirely appropriate for mid-story isolation structure, and the prolonging of structural natural period may not be able to decrease the seismic response of substructure and superstructure simultaneously. In this paper, for a four-story steel frame model, whose prototype first natural period is about 1s without seismic isolation design, the seismic responses and isolation effectiveness of mid-story isolation system with lead rubber bearing are studied experimentally by changing the location of isolation layer. Respectively, the locations of isolation layer are set at bottom of the first story, top of the first story, top of the second story and top of the third story. The results show that mid-story isolation can reduce seismic response in general, and substructure acceleration may be amplified.

Shaking Table Test Study on Mid-Story Isolation Structures with Viscous Damper

2012 ◽  
Vol 226-228 ◽  
pp. 1149-1152
Author(s):  
Jian Min Jin ◽  
Ping Tan ◽  
Fu Lin Zhou ◽  
Xiang Yun Huang
Keyword(s):  
Seismic Response ◽  
Seismic Isolation ◽  
Shaking Table Test ◽  
Base Isolation ◽  
Shaking Table ◽  
Viscous Damper ◽  
Natural Period ◽  
Isolation System ◽  
Isolation Layer ◽  
Complex Structural

Mid-story isolation structure is developing from base isolation structures. As a complex structural system, the work mechanism of base isolation structure is not entirely appropriate for mid-story isolation structure, and the prolonging of structural natural period may not be able to decrease the seismic response of substructure and superstructure simultaneously. In this paper, for a four-story steel frame model, whose prototype first natural period is about 1s without seismic isolation design, the seismic responses and isolation effectiveness of mid-story isolation system with linear natural rubber bearing and viscous damper are studied experimentally by changing the location of isolation layer. Respectively, the locations of isolation layer are set at bottom of the first story, top of the first story, top of the second story and top of the third story. The results show that mid-story isolation can reduce seismic response in general, and substructure acceleration may be amplified.

Fundamental Study on the Super-Long-Period Active Isolation System

2004 ◽  
Author(s):  
Keisuke Minagawa ◽  
Satoshi Fujita
Keyword(s):  
Control System ◽  
Seismic Isolation ◽  
Seismic Waves ◽  
Model Matching ◽  
Fundamental Study ◽  
Natural Period ◽  
Isolation System ◽  
Long Period ◽  
Rubber Bearings ◽  
Classical Control

Since the Hanshin-Awaji Earthquake Disaster, the number of isolated structures has been greatly increased. The natural period of the isolation system is designed around 3 seconds, because predominate period of observed seismic waves is usually 0.1 to 1 second. However, relatively long period seismic waves have been observed in various earthquakes, and the resonance of long-period structures, such as high-rise buildings, during earthquakes have been reported at the same time. Therefore the natural period needs to be extended. When extending the natural period of the isolated structure using rubber bearings, its stiffness needs to be reduced. It is more difficult to extend the natural period of the isolation system than the conventional system because of its buckling problem. Therefore we propose a super-long-period active seismic isolation system as a new method for extending the natural period of the isolated structure. This system consists of rubber bearings and actuators. In this study, we designed a control system by using the model-matching-method. This is one of the classical control system design methods. We investigated the isolation performance by numerical analysis. In addition, we selected the optimal variables of transfer function using genetic algorithm.

scholarly journals Dynamic Response of a Combined Isolation Based Mega-Substructure under Bidirectional Near-Fault Ground Motions

2018 ◽  
Vol 2018 ◽  
pp. 1-15
Author(s):  
Xueyuan Yan ◽  
Weihong Chen ◽  
Shen Shi ◽  
Xuan Wang
Keyword(s):  
Seismic Response ◽  
Seismic Isolation ◽  
Control Method ◽  
Ground Motions ◽  
Vibration Reduction ◽  
Shaking Table ◽  
Main Body ◽  
Isolation Layer ◽  
Near Fault ◽  
Model Structures

A typical megaframe structure has a high lateral stiffness and is excellent for high-rise structures. However, this high stiffness can lead to poor seismic response of a structure. Seismic isolation technology is a mature and cheap vibration control method that is used for vibration reduction in megaframes. This paper introduces a megaframe structure based on substructure combined isolation. The structure consists of two parts. The main body is a megaframe, and the substructure is the subframe with the combined isolation layer arranged at the bottom of the subframe. The seismic performance of this structure system was evaluated by performing shaking table tests of two megaframe model structures. The responses of the deformation, acceleration, and shear of the structure were measured. The dynamic behaviors of the structure with or without the combined isolation layer when exposed to single and bidirectional near-fault and far-fault ground motions with different peak values were investigated. The results showed that the combined isolation layer can reduce the bidirectional seismic response of the main frame and subframe. The acceleration, base shear, and displacement responses had similar vibration reduction trends for the two model structures, and the structural responses under bidirectional earthquake were generally greater than that under a single directional earthquake. The near-fault pulse effect increased the seismic response of the structure. The increase of the predominant period of ground motion also increased the seismic response of the structure.

Analysis of Effect on Seismic Response of Base Isolated Building with Openings Floor for the Elastic Stiffness of Isolation Layer

2014 ◽  
Vol 933 ◽  
pp. 316-319
Author(s):  
Ming Mei Jiang
Keyword(s):  
Seismic Response ◽  
Seismic Isolation ◽  
Elastic Stiffness ◽  
Frame Structure ◽  
Reinforced Concrete Frame ◽  
Concrete Frame ◽  
Isolation Layer ◽  
Reinforced Concrete Frame Structure ◽  
The Relationship ◽  
Selection Of

Currently the studies on the effects of seismic isolation layer parameters on seismic response of base isolated structure are so few. So this paper used the software ANSYS to analyze seismic response of a reinforced concrete frame structure with openings slab. It focused on the relationship between the isolation layer of the elastic stiffness and isolation effect, and provided reference for reasonable selection of seismic isolation layer parameters.

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