Seismic Response and Hysteric Performance Analysis in Different Base Isolated Structures

2013 ◽  
Vol 639-640 ◽  
pp. 891-895
Author(s):  
Ying Yuan ◽  
Ai Hong Zhou ◽  
Yan Li Gao
Keyword(s):  
Energy Dissipation ◽  
Performance Analysis ◽  
Seismic Response ◽  
Dynamic Responses ◽  
Sliding Bearings ◽  
Isolation System ◽  
Hysteretic Performance ◽  
Isolated Structures ◽  
Rubber Bearings ◽  
Isolated Systems

Firstly, the motion equation for parallel composite isolation system was formulated. Then, taking system with seven degree of freedoms for an illustrative example, the nonlinear dynamic responses of ordinary aseismic system, isolation system with friction sliding bearings, isolation system with laminated rubber bearings and parallel composite isolation system with the above combined bearings were calculated. Finally, the seismic responses of the above four structures were compared and discussed comprehensively and systematically, and the hysteretic performance of isolated floor was investigated. The results show that the isolation effect of isolated systems compared with the ordinary aseismic system is very notable and the hysteretic energy dissipation performance of isolated structures is excellent.

scholarly journals Lateral Seismic Response and Self-Centering Performance of a Long-Span Railway Continuous Beam-Arch Bridge

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Yan Shi ◽  
Zhanhong Zhang ◽  
Hongguo Qin ◽  
Xiangyu Zhao ◽  
Xiong Yang
Keyword(s):  
Energy Dissipation ◽  
Seismic Response ◽  
Seismic Isolation ◽  
The Self ◽  
Transverse Displacement ◽  
Continuous Beam ◽  
Sliding Bearings ◽  
Isolation System ◽  
Arch Bridge ◽  
Long Span

Based on the seismic isolation design concept of functional separation, a seismic isolation system with bearings and braces combination for railway bridge was proposed. The sliding bearings afford the vertical loads, and the self-centering energy dissipation brace (SCED) and buckling restrained brace (BRB) control the horizontal displacement of the beam, so the functional separation was achieved under the combined action. Taking a long-span railway continuous beam-arch bridge as an example, the corresponding analysis model was established to study lateral seismic response and the girder’s displacement pattern of the continuous beam-arch bridge under the earthquake excitations. The seismic response of bridges with different seismic isolation schemes was studied. The result showed that the presence of arch rib in a continuous beam-arch bridge amplifies the transverse displacement response of the girder compared with that in a continuous beam bridge of equal mass. The seismic isolation system with sliding bearings and energy dissipation braces can control the relative displacement between the pier and beam greatly, and the SCED can reduce or even eliminate the residual displacement between pier and beam. Furthermore, under the strong ground motions, the combined use of SCED and BRB can achieve the seismic isolation to the maximum extent when the self-centering force ratio ζ, the ratio of self-centering force to superstructure weight, is 0.074.

scholarly journals STRUCTURAL DESIGN OF HIGH-RISE BUILDING WITH BASE ISOLATION SYSTEM USING ELASTIC SLIDING BEARINGS AND RUBBER BEARINGS

2001 ◽  
Vol 7 (12) ◽  
pp. 99-104 ◽  
Author(s):  
Ichizo KAWABATA ◽  
Masaharu TAKAYAMA ◽  
Yasuhiro NISHIKAWA ◽  
Yuichi KIMURA ◽  
Eiichi YAMAZAKI ◽  
...  
Keyword(s):  
Structural Design ◽  
Base Isolation ◽  
Sliding Bearings ◽  
Isolation System ◽  
High Rise ◽  
High Rise Building ◽  
Base Isolation System ◽  
Rubber Bearings

Research and Development of Three-Dimensional Isolation System for Sodium-Cooled Fast Reactor: Part 1 — Proposal of Analytical Models Based on Loading Tests

2018 ◽  
Author(s):  
Tsuyoshi Fukasawa ◽  
Shigeki Okamura ◽  
Takahiro Somaki ◽  
Takayuki Miyagawa ◽  
Masato Uchita ◽  
...  
Keyword(s):  
Seismic Response ◽  
Analytical Model ◽  
Three Dimensional ◽  
Analytical Models ◽  
Response Analysis ◽  
Seismic Response Analysis ◽  
Natural Period ◽  
Isolation System ◽  
Loading Tests ◽  
Rubber Bearings

This paper describes that the analytical model for the three-dimensional isolation system [1], which consists of thick rubber bearings, disc springs and oil dampers, is created through loading tests. The new-type analytical models of each element are proposed to improve the prediction accuracy of the seismic response analysis. The concept of the three-dimensional isolation system has been proposed to ensure the structural integrity for large reactor vessels. The primary specifications of the three-dimensional isolation system are a horizontal natural period of 3.4 s and a vertical natural period of 0.33 s. The investigations of horizontal isolation performances have been conducted for the various types of isolation devices, beginning with rubber bearings, whereas the previous studies focused on the vertical isolation performances are only a few. Hence, isolation characteristics, such as restoring force and damping force, should be clarified by loading tests using vertical seismic isolation elements, and analytical model to assess the seismic response should be identified on the basis of the loading test results. This paper presents a new analytical model with providing of the differential equations to improve the prediction accuracy and demonstrates the seismic performance, including beyond-design-basis ground motion, for the three-dimensional isolation system by the seismic response analysis.

Influence of the Strain Hardening of HDRBs in the Evaluation of the Seismic Response of a RC Base Isolated Structure

2012 ◽  
Vol 602-604 ◽  
pp. 1546-1554
Author(s):  
Donato Cancellara ◽  
Fabio de Angelis ◽  
Mario Pasquino
Keyword(s):  
Strain Hardening ◽  
Seismic Response ◽  
Base Isolation ◽  
Cyclic Behavior ◽  
Hysteretic Model ◽  
Isolation System ◽  
Limit Value ◽  
Hardening Effect ◽  
Base Isolation System ◽  
Rubber Bearings

In this paper we have analyzed the influence of the strain hardening behavior of High Damping Rubber Bearings (HDRBs) adopted for a base isolation system of a Reinforced Concrete (RC) isolated structure. For the modeling of the rubber isolators we have adopted an evolution of the Bouc-Wen’s hysteretic model taking into account the incremental hardening effect which appears when the shear strain of the HDRB exceeds the limit value around 100% usually adopted in design practice. The incremental hardening effect is sometimes neglected in the design but it is an important aspect because it ensures a seismic protection of the base isolated structure also in presence of exceptional seismic events for intensity or frequency content. In this paper we have highlighted the significant influence of this phenomenon in the seismic response of the isolated structure by reporting the cyclic behavior of a HDRB respectively neglecting and considering this aspect.

Comparative Study on Nonlinear Earthquake Response of Girder Isolated Bridges with LRB and Model Shaking Table Test

2013 ◽  
Vol 706-708 ◽  
pp. 472-477
Author(s):  
Jie Dong Zhan ◽  
Xin Tong Li ◽  
Yang Li
Keyword(s):  
Seismic Response ◽  
Shaking Table Test ◽  
Experimental Results ◽  
Shaking Table ◽  
Vertical Force ◽  
Isolation System ◽  
Nonlinear Seismic Response ◽  
Girder Bridges ◽  
Deformation Properties ◽  
Rubber Bearings

Abstract: The thesis is aimed to study the characteristics nonlinear seismic response of the isolated continuous girder bridges with LRB. Inorder to achieve the aim, force- deformation properties of the LRB is considered as bilinear first, the bouc-wen model is adopted to imitate the force nonlinear deformation behavior of LRB, and by using Finite element method, the motion equation of the Isolation system of continuous girder bridge is established, then some shaking table tests towards the model of isolated continuous girder bridges with LRB is done. On this basis of it, by comparing the experimental results and calculation results, such as the acceleration and displacement of deck, vertical force of bearing, and the relationship between the Isolation layer displacement and the Level force displacement of the Bearing, we can see that the difference between the analytical results and the experimental results are very small. The results show that the calculation method can analyze Nonlinear Seismic Response of isolated continuous girder bridges with LRB efficiently. But when the vertical earthquake component is larger ,whether the results of the Vertical tension are produced or not, designing the Rubber bearings should be considered.

Research on Isolated Strengthening of Erose School Buildings

2011 ◽  
Vol 94-96 ◽  
pp. 1298-1303
Author(s):  
Xi Sen Fan ◽  
Shu Zhen Ren
Keyword(s):  
Seismic Response ◽  
Masonry Structure ◽  
School Buildings ◽  
Isolation System ◽  
Torsional Response ◽  
Rubber Bearing ◽  
Lead Rubber Bearing ◽  
Lead Rubber Bearings ◽  
Rubber Bearings ◽  
Strengthening Technique

The aseismatic strengthening technique for masonry structure was researched in this paper. The seismic response of a L-type school building with and without isolation system were computed by using software SAP2000. The isolation system were made up of lead rubber bearings or combined Isolation system. The results showed that base-isolated strengthening can reduce not only the translational response but also the torsional response with earthquake. The combined Isolation system was more effetive in decreasing translational response than the lead rubber bearing, but inferior to in decreasing torsion response.

scholarly journals FREQUENCY CHARACTERISTICS OF SEISMIC ISOLATION SYSTEM USING SLIDING BEARINGS AND MULTI-RUBBER BEARINGS(Structures)

2003 ◽  
Vol 9 (17) ◽  
pp. 159-164
Author(s):  
Masahiko OZAKI ◽  
Yousuke MURAKAMI ◽  
Naohiko TSUNASHIMA ◽  
Tomio NAKANO ◽  
Ryota MASEKI ◽  
...  
Keyword(s):  
Seismic Isolation ◽  
Frequency Characteristics ◽  
Sliding Bearings ◽  
Isolation System ◽  
Rubber Bearings

Feasibility Analysis of SMA-Based Damping Devices for Use in Seismic Isolation of Low-Rise Frame Buildings

2018 ◽  
Vol 18 (06) ◽  
pp. 1850087 ◽  
Author(s):  
Canxing Qiu ◽  
Li Tian
Keyword(s):  
Energy Dissipation ◽  
Strain Hardening ◽  
Seismic Isolation ◽  
Original Position ◽  
Isolation System ◽  
Hardening Behavior ◽  
Frame Building ◽  
Frame Buildings ◽  
Rubber Bearings ◽  
Strain Hardening Behavior

For seismic isolated buildings, the isolators should be able to control peak deformation and have good restoring ability to return the building to its original position. Shape memory alloys (SMAs) are known for their properties of energy dissipation and deformation recovery, which make them appealing for use in isolation systems. To this end, the feasibility of SMA-based damping devices for use in an isolation system of low-rise frame buildings is studied in this paper. Numerical analyses were conducted and compared for buildings installed with SMA-based bearings (SMABs) and lead-rubber bearings (LRBs). A two-mass isolated frame building installed with these bearings was subjected to earthquakes corresponding to multilevel seismic hazards. The results show that the SMABs offer comparable seismic hazard mitigation efficacy to that of the LRBs while successfully restoring the building to the rest position after the earthquake. Furthermore, adding the energy dissipation capacity and properly using the strain hardening behavior of the SMAs are favorable for controlling isolation deformation while protecting the superstructure. The strain hardening behavior of the SMABs is beneficial for controlling deformation at the isolator level, which can still maintain isolation efficacy.

Aseismic Roof Isolation System Built with Steel Oval Elements: Exploratory Study

2005 ◽  
Vol 21 (1) ◽  
pp. 225-241 ◽  
Author(s):  
Roberto Villaverde ◽  
Manuel Aguirre ◽  
Charles Hamilton
Keyword(s):  
Experimental Study ◽  
Seismic Response ◽  
Exploratory Study ◽  
Inelastic Deformation ◽  
Earthquake Damage ◽  
Shaking Table ◽  
Sliding Bearings ◽  
Isolation System ◽  
Isolation Technique ◽  
Small Steel

Presented herein are the details of and results from an experimental study conducted to assess the feasibility and effectiveness of a proposed roof isolation system whose purpose is to reduce earthquake damage in buildings. The proposed isolation system entails the detachment of a building's roof from the rest of the building through the insertion of sliding bearings and the attachment of oval-shaped steel elements between the building's roof and the structure below. The objective is to form a simple resonant oscillator with a building's roof and these oval elements, with the roof providing the mass of the oscillator and the oval elements its spring and damper. An additional intention is to make the steel oval elements undergo a large number of inelastic deformation cycles and dissipate, as a result, a large portion of the energy transmitted to a building during an earthquake. The study involves the testing of a small steel frame on a shaking table alternatively with and without the proposed roof isolation system and a comparison of the story drifts and floor accelerations attained in each case. In the conducted tests, the suggested isolation technique effectively reduces the seismic response of the frame. It is concluded, thus, that the proposed roof isolation system has the potential for the development of an inexpensive and effective way to reduce earthquake damage in some buildings and merits further study.

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