Dynamic Response Analysis of MSCSS Constructed with Rubber Vibration Isolator

2014 ◽  
Vol 574 ◽  
pp. 179-183
Author(s):  
Tao Li

The seismic responses of the mega-sub controlled structural system (MSCSS) can be reduced effectively based on the combination of the construction and control theory. One of the main construction features of the MSCSS is the connection between the additional column and the mega beam. The rubber vibration isolator is proposed as a new connection mode between the above two components according to the base isolation technique. The dynamic responses of the MSCSS subjected to the earthquake excitation are investigated by employing the probability density evolution method. The analysis results are compared with the seismic responses of the MSCSS constructed with other connection modes. The results show that the seismic responses of the MSCSS constructed with rubber vibration isolator can be reduced effectively, but the effect is not better than the other connection modes.

2010 ◽  
Vol 163-167 ◽  
pp. 4014-4021
Author(s):  
Xiang Yun Huang ◽  
Fu Lin Zhou ◽  
She Liang Wang ◽  
Liu Han Wen Heisha ◽  
Xue Hai Luo

Isolation technique has been acceded as a part of the China Seismic Code for Design of Buildings. In this code, the limitations for using isolation design are very strict, superstructure must be regular and the isolation layer must be located on the top of base (base isolated structure). Because of the needs of architecture and function or the feasibility of technique, some limitations have been broken in recent projects. Sometimes isolated layer can be set on the intermediate story, so-called the mid-story isolated structure. According to the characteristic of structure, isolation layer of mid-story isolated structure is set on a place where the structure’s vertical stiffness is suddenly changed, as like the top of the first story, middle story, conversion story of the structure. Laminated rubber bearings (LRB) are adopted as an isolation layer. Because the isolation layer is set on intermediate story, the whole structure is divided into superstructure and substructure; the structure’s dynamic characteristics are changed. The mechanism of mid-story isolated structure appears different characteristic compared with base isolation. The aim of mid-story isolation is not only to reduce seismic responses of superstructure, but also to reduce seismic responses of the substructure. Theoretical analysis and the shaking table test of the mid-story isolated structure were carried. And the response of mid-story isolated structure is discussed by comparing with the response of base-isolated structure and base fixed structure. The key problems of mid-story isolated structure are the force condition and the interaction of the structure up and below the isolation layer. Many factors, such as the number of story, mass, stiffness of superstructure and substructure, parameter of the isolation layer, have influence on the seismic behavior of the mid-story isolated structure. The optimum combination relationship of these factors is presented and dynamic characteristics and dynamic responses are investigated.


2012 ◽  
Vol 256-259 ◽  
pp. 1480-1483
Author(s):  
Xin Huang ◽  
Zhao Wei Huang ◽  
Xue Ying Hu ◽  
Hao Liang Cai ◽  
Lin Qi ◽  
...  

In order to ensure safety of long and huge bridges in deep water under earthquake action, it is significance to consider water and bridge pier dynamic interaction. Analysis method of water-bridge pier dynamic interaction under earthquake excitation is established using radiation wave theory, and earthquake induced hydrodynamic pressure apply program is complied. Considering different earthquake wave input, earthquake induced hydrodynamic pressure influence on dynamic responses of bridge pier in deep water is further studied. The results indicate that: Dynamic response of bridge pier in deep water is augmented because of hydrodynamic pressure action. Earthquake induced hydrodynamic pressure influence on seismic responses of bridge piers in deep water will change with different input earthquake wave.


2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Zhi Zheng ◽  
Xiaolan Pan ◽  
Xu Bao

The sequential ground motion effects on the dynamic responses of reinforced concrete containment (RCC) buildings with typical isolators are studied in this paper. Although the base isolation technique is developed to guarantee the security and integrity of RCC buildings under single earthquakes, seismic behavior of base-isolated RCC buildings under sequential ground motions is deficient. Hence, an ensemble of as-recorded sequential ground motions is employed to study the effect of including aftershocks on the seismic evaluation of base-isolated RCC buildings. The results indicate that base isolation can significantly attenuate the earthquake shaking of the RCC building under not only single earthquakes but also seismic sequences. It is also found that the adverse aftershock effect on the RCC can be reduced due to the base isolation applied to the RCC. More importantly, the study indicates that disregarding aftershocks can induce significant underestimation of the isolator displacement for base-isolated RCC buildings.


Author(s):  
Osamu Furuya ◽  
Kiyotaka Takito ◽  
Hiroshi Kurabayashi ◽  
Kunio Sampei ◽  
Koji Yamazaki

Abstract Vibration isolation devices are generally applied to equipment that dislikes vibration installed in buildings. Since the vibration isolator is intended for small vibration input, the damage has been frequently confirmed with excessive vibration input such as an huge earthquake motion. Therefore, the development of a seismic isolation device with a vibration isolation function is desired for important equipment and expensive manufacturing equipment. However, the vibration region targeted by the vibration isolator and the vibration region of the seismic input are at completely different levels. In this study, the authors propose a seismic isolation system using air floating technique to cope with such different vibration levels. In this paper, basic concept, basic performance, preliminary performance evaluation by nonlinear time response analysis, and performance evaluation by shaking table test.


2018 ◽  
Vol 2018 ◽  
pp. 1-21 ◽  
Author(s):  
Khaled Ghaedi ◽  
Zainah Ibrahim ◽  
Mohammed Jameel ◽  
Ahad Javanmardi ◽  
Hamed Khatibi

In populous cities, construction of multistorey buildings close to each other due to space limitation and increased land cost is a dire need. Such construction methods arise several problems during earthquake excitation. The aim of this study is to investigate the bidirectional seismic responses of fully base-isolated (FBI) adjacent buildings having different heights and segregated foundations. Therefore, two scenarios, namely, (a) investigation of the responses of FBI adjacent buildings compared to those with fixed base (FFB) and (b) the effects of separation distance on FBI adjacent buildings, were studied. Based on these investigations, the results showed that isolation system significantly enhances the overall responses of the BI buildings. Spectacularly, the base isolation system was further efficient to decrease displacement rather than the acceleration. In addition, increase of the seismic gap changed the acceleration, pounding, base shear, base moment, and storey drift, as well as the force-deformation performance of the isolators. Therefore, it seems a need to focus on the effect of the separation distances for the design of base isolators for FBI adjacent buildings in future works.


2021 ◽  
Vol 11 (14) ◽  
pp. 6295
Author(s):  
Konstantinos Kapasakalis ◽  
Ioannis Antoniadis ◽  
Evangelos Sapountzakis

Conventional base isolation (BI) techniques require a great reduction in the fundamental frequency of the system in order to mitigate the structural dynamic responses due to earthquake excitations. However, the resulting base displacements are large and can cause utility connection problems, rendering BI inadequate for retrofitting. This paper proposes a vibration control system (VCS) that can be used as a supplement to the conventional BI to increase the effective damping, and thus reduce the required base displacements. A novel passive negative stiffness (NS)-based vibration absorber, based on the KDamper, is implemented in parallel to a BI. The design of the VCS follows a constrained optimization approach that accounts for geometrical and manufacturing limitations. The NS is realized with a realistic displacement-dependent mechanism that generates controlled NS. The VCS is designed for various soil-types in order to determine its effectiveness and soil-structure-interaction (SSI) effects are accounted with respect to the soil-type. The earthquake excitation input is selected according to the EC8 by generating a database of artificial accelerograms for each ground type. Finally, the VCS is compared to a conventional BI, and based on the numerical results obtained, the VCS is an effective alternative to BI and a possible retrofitting option.


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