Experimental Study of a Multiple Bay Structure Isolated With Hybrid Bearings

In conventional earthquake resistance design approach (the ductility-design philosophy), the energy dissipation mechanism is based on plastic deformations at scattered locations in the structure. However, this can produce permanent damage to the joints as well as the larger interstory displacements. In recently years, the base isolation technology has been adopted as a feasible and attractive way in improving seismic resistance of structures. It can shift the natural periods of structures away from the rich periods contents of earthquake motions, but also provide considerable supplemental damping to dissipate seismic energy transmitted into structures during earthquakes. In this paper, uniaxial, biaxial, and triaxial shaking table tests are performed to study the seismic behavior of a 0.4-scale three-story isolated steel structure in the National Center for Research on Earthquake Engineering in Taiwan. Experimental results demonstrate that structures with hybrid rubber bearings can actually decrease the seismic responses of the superstructure. It has been proved through the shaking table tests that the rubber bearing is a very promising tool to enhance the seismic resistibility of structures. Moreover, it is illustrated that the proposed analytical model and finite element formulation in this paper can well predict the mechanical behavior of rubber bearings and seismic responses of the base-isolated structures.

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Shaking Table Tests of Full Scale Base-Isolated Structures

Seismic Engineering, Volume 2 ◽

10.1115/pvp2002-1453 ◽

2002 ◽

Author(s):

C. S. Tsai ◽

B. J. Chen ◽

T. C. Chiang

Keyword(s):

Structural Control ◽

Control Strategies ◽

Steel Structure ◽

Seismic Energy ◽

Full Scale ◽

Shaking Table ◽

Shaking Table Tests ◽

Natural Period ◽

Rubber Bearing ◽

Rubber Bearings

Conventional earthquake resistant designs depend on strengthen and ductility of the structural components to resist induced forces and to dissipate seismic energy. However, this can produce permanent damage to the joints as well as the larger interstory displacements. In recently years, many studies on structural control strategies and devices have been developed and applied in U. S. A., Europe, Japan, and New Zealand. The rubber bearing belongs to one kind of the earthquake-proof ideas of structural control technologies. The installation of rubber bearings can lengthen the natural period of a building and simultaneously reduce the earthquake-induced energy trying to impart to the building. They can reduce the magnitude of the earthquake-induced forces and consequently reduce damage to the structures and its contents, and reduce danger to its occupants. This paper is aimed at studying the mechanical behavior of the stirrup rubber bearings (SRB) and evaluating the feasibility of the buildings equipped with the stirrup rubber bearings. Furthermore, uniaxial, biaxial, and triaxial shaking table tests are conducted to study the seismic response of a full-scale three-story isolated steel structure. Experimental results indicate that the stirrup rubber bearings possess higher damping ratios at higher strains, and that the stirrup rubber bearings provide good protection for structures. It has been proved through the full-scale tests on shaking table that the stirrup rubber bearing is a very promising tool to enhance the seismic resistibility of structures.

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Analysis and Experiment on the Effect of Seismic Protection of Buildings by High Damping Rubber Bearings

Seismic Engineering, Volume 1 ◽

10.1115/pvp2004-2959 ◽

2004 ◽

Author(s):

Jun-Ping Pu ◽

C. S. Tsai ◽

Jian-Fa Huang ◽

Bo-Jen Chen ◽

Yao-Min Fang

Keyword(s):

Earthquake Engineering ◽

Base Isolation ◽

Steel Structure ◽

Shaking Table ◽

Natural Period ◽

Rubber Bearing ◽

High Damping Rubber Bearings ◽

High Damping Rubber Bearing ◽

High Damping Rubber ◽

Rubber Bearings

In recent years, many studies on base isolation strategies and devices have been developed and applied in U. S. A., Europe, Japan, and New Zealand. The high damping rubber bearing belongs to one kind of the earthquake-proof ideas of base isolation technologies. The installation of high damping rubber bearings can lengthen the natural period of a building and simultaneously reduce the earthquake-induced energy trying to impart to the building. The objective of this paper is to investigate the base isolation effect of high damping rubber bearings. The uniaxial, biaxial, and triaxial shaking table tests were performed to study the seismic behavior of a 0.4-scale three-story isolated steel structure in the National Center for Research on Earthquake Engineering in Taiwan. The experimental and analytical results show that the nonlinear mechanical characteristics of the high damping rubber bearings can be reasonably simulated.

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Seismic Responses of a Full-Scale Steel Structure Using Multi-Curved Buckling Restrained Braces

Volume 8: Seismic Engineering ◽

10.1115/pvp2007-26554 ◽

2007 ◽

Author(s):

C. S. Tsai ◽

Wen-Shin Chen ◽

Yung-Chang Lin ◽

Chen-Tsung Yang ◽

Ching-Pei Tsou

Keyword(s):

Earthquake Engineering ◽

Ground Motions ◽

Steel Structure ◽

Full Scale ◽

Experimental Results ◽

Shaking Table ◽

Shaking Table Tests ◽

Seismic Responses ◽

Buckling Restrained Brace ◽

Buckling Restrained Braces

Since 1970’s, many types of braces have been developed without buckling under large compressive forces called the buckling restrained brace BRB, or unbonded brace. Recently, many investigators have made a lot of efforts to look into the behaviors of the buckling restrained brace under quasi-static forces, but few experimental results about shaking table tests of a structure with buckling restrained braces have been published. Therefore, in this study, a series of shaking table tests were carried out in the National Center for Research on Earthquake Engineering, and the issue is focused on observing the seismic responses of a full-scale three-story steel structure with multi-curved reinforced buckling restrained braces subjected to earthquake ground motions. Experimental results show that most column shear forces and displacements had been reduced by the RBRB devices. In addition, the absolute accelerations had also been favorably diminished during earthquakes. It can be proven that the proposed device is suitable for applications of seismic mitigation for structures.

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Shaking Table Tests of a Full Scale Steel Structure Isolated With MFPS

Seismic Engineering ◽

10.1115/pvp2003-2100 ◽

2003 ◽

Cited By ~ 8

Author(s):

C. S. Tsai ◽

Tsu-Cheng Chiang ◽

Bo-Jen Chen

Keyword(s):

Earthquake Engineering ◽

Stress Responses ◽

Passive Control ◽

Base Isolation ◽

Experimental Results ◽

Shaking Table ◽

Element Formulation ◽

Shaking Table Tests ◽

Pendulum System ◽

Residual Displacements

The base isolation, a kind of passive control technology, has been proved as a very efficient way to ensure the safety of a structure during severe earthquakes both from theoretical study and experimental effort. In general, the base isolation can be classified into two groups, which are sliding type and elastomeric type isolator. In this study, a new base isolator called as Multiple Friction Pendulum System (MFPS) has been proposed. The lubricant material, articulated slider and doubled concave sliding interfaces of MFPS are quite different from that proposed by V. Zayas in 1987. In this study, the MFPS isolator has been equipped beneath each column of a three-story structure at the National Center for Research on Earthquake Engineering to demonstrate its seismic resistance capability. The experimental results from shaking table tests of the 1940 El Centro, 1995 Kobe and 1999 Chi-Chi earthquake show that the proposed isolator can reduce the undesirable seismic response of the structure by lengthening the fundamental period of the structure during earthquakes. The experimental results indicate that the acceleration response of each floor can be lessened significantly as compared with those of the bare structure, and that the stress responses of structural components are limited in the certain range during severe earthquakes. Furthermore, the residual displacements of base isolators are negligible. Therefore, it is shown evidently that the proposed isolator can always bring the base-isolated structure to its initial position after an earthquake. Based on the previous observations, the proposed isolator can be adopted as an effective tool for upgrading the seismic resistibility of a structure. A finite element formulation for the MFPS is also proposed to simulate its mechanical behavior during earthquakes.

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Comparative dynamic investigation of cross-laminated wooden panel systems: Shaking-table tests and analysis

Advances in Structural Engineering ◽

10.1177/1369433217749766 ◽

2017 ◽

Vol 21 (10) ◽

pp. 1421-1436 ◽

Cited By ~ 2

Author(s):

Viktor Hristovski ◽

Violeta Mircevska ◽

Bruno Dujic ◽

Mihail Garevski

Keyword(s):

Energy Dissipation ◽

Earthquake Engineering ◽

Dynamic Properties ◽

Seismic Energy ◽

Experimental Tests ◽

Shaking Table ◽

Shaking Table Tests ◽

Equivalent Viscous Damping ◽

Cross Laminated Timber ◽

Engineering Seismology

Cross-laminated timber has recently gained great popularity in earthquake-prone areas for construction of residential, administrative, and other types of buildings. At the Laboratory of the Institute of Earthquake Engineering and Engineering Seismology in Skopje, comparative full-scale shaking-table tests of cross-laminated timber panel systems have been carried out as a part of the full research program on the seismic behavior of these types of wooden systems, realized by Institute of Earthquake Engineering and Engineering Seismology, Skopje, and the Faculty of Civil and Geodetic Engineering (UL FCG), University of Ljubljana. Two different specimens built of cross-laminated timber panels have been tested: specimen containing a pair of single-unit principal wall elements (Specimen 1) and specimen containing a pair of two-unit principal wall elements (Specimen 2). In this article, the results from the shaking-table tests obtained for Specimen 2 and numerically verified by using appropriate finite element method–based computational model are discussed. Reference is also made to the comparative analysis of the test results obtained for both specimens. One of the most important aspects of the research has been the estimation of the seismic energy-dissipation ability of Specimen 1 and 2, via calculation of the equivalent viscous damping using the performed experimental tests. It is generally concluded that Specimen 2 exhibits a similar rocking behavior as Specimen 1, with similar energy-dissipation ability. Both specimens have manifested slightly different dynamic properties, mostly because Specimen 2 has been designed with one anchor more compared to Specimen 1. Forced vibration tests have been used for identification of the effective stiffness on the contacts for Specimen 2. This research is expected to be a contribution toward clarification of the behavior and practical design of cross-laminated timber panel systems subjected to earthquake loading.

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Experimental Investigation on Mid-Story Isolated Structures

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.163-167.4014 ◽

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

Keyword(s):

Dynamic Characteristics ◽

Shaking Table Test ◽

Base Isolation ◽

Shaking Table ◽

Dynamic Responses ◽

Seismic Responses ◽

Isolation Technique ◽

Vertical Stiffness ◽

Isolation Layer ◽

Rubber Bearings

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.

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An Improved FPS Isolator for Seismic Mitigation on Steel Structure

Seismic Engineering, Volume 2 ◽

10.1115/pvp2002-1452 ◽

2002 ◽

Author(s):

C. S. Tsai ◽

Tsu-Cheng Chiang ◽

Chia-Kuan Cheng ◽

Wen-Shin Chen ◽

Chih-Wei Chang

Keyword(s):

Spherical Surface ◽

Structural Response ◽

Steel Structure ◽

Experimental Results ◽

Shaking Table ◽

Element Formulation ◽

Shaking Table Tests ◽

Surface Type ◽

Sliding Interface ◽

Seismic Loadings

Structure equipped with base isolators to decouple the superstructure from its foundation has been recognized as an effective and feasible way to mitigate structural response subjected to seismic loadings. In this study, a new lubricant material for the FPS isolator has been developed. The experimental results from shaking table tests show that the acceleration responses of floors of a structure isolated by the FPS isolators coated with the new Teflon composite can be lessened within a desirable range, and the steel structure with the FPS isolators moves nearly as rigid body motions during earthquakes. To verify the durability of the FPS isolators, the component tests of sliding interface coated with advanced Teflon composite and shaking table tests of steel structure with the FPS isolators subjected to hundreds of earthquake events were performed in this study. The experimental results demonstrate that the advanced Teflon composite can sustain hundreds of reversal loadings, therefore, it can be adopted to lubricate the sliding interface of the FPS isolators. Furthermore, a simplified and a finite element formulation for bilateral-spherical-surface-type FPS have been proposed in this study. The numerical results show that the proposed formulation can well predict the dynamic response of structure with bilateral-spherical-surface-type FPS than the formulation proposed by S. Okamura et at.

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Shaking Table Tests of a Building Isolated With Trench Friction Pendulum System

Volume 8: Seismic Engineering ◽

10.1115/pvp2006-icpvt-11-93253 ◽

2006 ◽

Author(s):

C. S. Tsai ◽

Po-Ching Lu ◽

Wen-Shin Chen

Keyword(s):

Seismic Isolation ◽

Steel Structure ◽

Shaking Table ◽

Engineering Practice ◽

Shaking Table Tests ◽

Pendulum System ◽

Promising Tool ◽

Friction Pendulum ◽

Design And Manufacture ◽

Friction Pendulum System

It has been proven that the seismic isolation technology is a very promising tool to lessen damage caused by earthquakes. In order to provide a cheap and efficient base isolator for engineering practice, a new isolator named the trench friction pendulum system (TFPS), which is easy to design and manufacture, is proposed in this study. A series of shaking table tests of a scaled steel structure equipped with TFPS isolators were performed in the Department of Civil Engineering, Feng Chia University, Taichung, Taiwan. Experimental results demonstrate that the TFPS isolator can isolate most of earthquake induced energy trying to impart into the superstructure and that the device is not only cheap but also efficient for seismic mitigation.

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