Dynamic Nonlinear Analysis of an Hybrid Base Isolation System with Viscous Dampers and Friction Sliders in Parallel

2012 ◽  
Vol 234 ◽  
pp. 96-101 ◽  
Author(s):  
Donato Cancellara ◽  
Fabio de Angelis
Keyword(s):  
Nonlinear Analysis ◽  
Base Isolation ◽  
Three Dimensional ◽  
Time History ◽  
Seismic Action ◽  
Viscous Dampers ◽  
Isolation System ◽  
Fixed Base ◽  
Base Isolation System ◽  
Dynamic Nonlinear Analysis

In the present work we have analyzed a particular base isolation system for the seismic protection of a multi-storey reinforced concrete (RC) building. The viscous dampers and friction sliders are the devices adopted in parallel for realizing the base isolation system. The base isolation structure has been designed and verified according to European seismic code EC8 and by considering for the friction sliders the influence of the sliding velocity on the value of the friction coefficient. A dynamic nonlinear analysis for a three-dimensional base isolated structure has been performed. Recorded accelerograms for bi-directional ground motions have been used which comply with the requirements imposed by EC8 for the representation of a seismic action in a time history analysis. In this paper a comparative analysis is presented between the base isolated structure with the described hybrid base isolation system and the traditional fixed base structure.

Hybrid Base Isolation System with Friction Sliders and Viscous Dampers in Parallel: Comparative Dynamic Nonlinear Analysis with Traditional Fixed Base Structure

2012 ◽  
Vol 594-597 ◽  
pp. 1771-1782 ◽  
Author(s):  
Donato Cancellara ◽  
Fabio de Angelis
Keyword(s):  
Nonlinear Analysis ◽  
Base Isolation ◽  
Protection System ◽  
Seismic Protection ◽  
Viscous Dampers ◽  
Isolation System ◽  
Fixed Base ◽  
Base Isolation System ◽  
Dynamic Nonlinear Analysis ◽  
Base Structure

In the present paper we have analyzed a multi-storey reinforced concrete (RC) building in presence of a hybrid seismic protection system for highlighting the limits of the conventional fixed base seismic design of structures. This hybrid seismic protection system is a passive structural control system that combines the Base Isolation System (BIS) and the Passive Supplemental Damping (PSD). The Viscous Dampers (VS) and Friction Sliders (FS) are the devices adopted in parallel for realizing the innovative base isolation system. The fixed base structure and the base isolated structure have been designed and verified according to the European seismic code EC8 and the European code for the design of concrete structures EC2. A three-dimensional dynamic nonlinear analysis for a base isolated structure has been performed adopting recorded accelerograms for the defined bi-directional ground motions according to the conditions imposed by EC8. The seismic isolation is a promising alternative for the earthquake resistant design of buildings and its peculiarity is that the base isolated buildings are designed such that the superstructure remains elastic and the nonlinearities are localized at the isolation level. In this paper a comparative analysis is presented between the base isolated structure, with the viscous dampers in parallel with friction sliders, and the traditional fixed-base structure.

scholarly journals Analysis, Design, and Construction of a Base-Isolated Multiple Building Structure

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Stefano Sorace ◽  
Gloria Terenzi
Keyword(s):  
Base Isolation ◽  
Time History ◽  
Residential Building ◽  
Longitudinal Direction ◽  
Isolation System ◽  
Expansion Joints ◽  
Analysis And Design ◽  
Fixed Base ◽  
Base Isolation System ◽  
Nonlinear Time History

The analysis and design of a multiple residential building, seismically protected by a base isolation system incorporating double friction pendulum sliders as protective devices, are presented in the paper. The building, situated in the suburban area of Florence, is composed of four independent reinforced concrete framed structures, mutually separated by three thermal expansion joints. The plan is L-shaped, with dimensions of about 75 m in the longitudinal direction and about 30 m along the longest side of the transversal direction. These characteristics identify the structure as the largest example of a base-isolated “artificial ground” ever built in Italy. The base isolation solution guarantees lower costs, a much greater performance, and a finer architectural look, as compared to a conventional fixed-base antiseismic design. The characteristics of the building and the isolators, the mechanical properties and the experimental characterization campaign and preliminary sizing carried out on the latter, and the nonlinear time-history design and performance assessment analyses developed on the base isolated building are reported in this paper, along with details about the installation of the isolators and the plants and highlights of the construction works.

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.

INFLUENCE OF HIGH INITIAL ISOLATOR STIFFNESS ON THE SEISMIC RESPONSE OF A BASE-ISOLATED BENCHMARK BUILDING

2011 ◽  
Vol 11 (06) ◽  
pp. 1201-1228 ◽  
Author(s):  
AJAY SHARMA ◽  
R. S. JANGID
Keyword(s):  
Degrees Of Freedom ◽  
Base Isolation ◽  
Near Field ◽  
Equations Of Motion ◽  
Three Dimensional ◽  
Time History ◽  
Base Shear ◽  
Isolation System ◽  
Base Displacement ◽  
Floor Acceleration

The influence of high initial isolator stiffness on the response of a base-isolated benchmark building is investigated. The base-isolated building is modeled as a three-dimensional linear-elastic structure having three degrees-of-freedom at each floor level. The time-history analysis of this building is carried out by solving the governing equations of motion using Newmark-beta method along with an iterative predictor–corrector approach. The force–deformation behavior of the isolation system is modeled by a bilinear law, which can be effectively used to model all isolation systems in practice. Three near-field earthquakes with bidirectional ground motions are considered. Structural response parameters such as absolute top floor acceleration, base shear, and base displacement are chosen for investigating the effects of high initial isolator stiffness. It was observed that the high initial isolator stiffness of the isolation system excites the higher modes in the base-isolated building and increases the top floor acceleration. Such a phenomenon can be detrimental to the sensitive instruments placed in the isolated structure. On the other hand, both the base displacement and base shear reduce marginally due to increase in the initial isolator stiffness. Further, the influences of high initial isolator stiffness are found to dependent on the period and characteristic strengths of the base isolation system.

scholarly journals Seismic Performances of Conventional and LRB-Isolated Buildings Comparing to Seesaw Buildings

2020 ◽  
Vol 10 (1) ◽  
pp. 45-54
Author(s):  
Soroush Kherad ◽  
Mahmood Hosseini ◽  
Mehrtash Motamedi
Keyword(s):  
Base Isolation ◽  
Low Cost ◽  
Time History ◽  
Building Structure ◽  
Base Shear ◽  
Isolation System ◽  
Repair Work ◽  
Story Drift ◽  
Base Isolation System ◽  
Nonlinear Time History

AbstractUsing seesaw structural system equipped with energy dissipating devices has been considered as a low-cost and low-tech way for creation of earthquake-resilient buildings. In this paper by considering three groups of multi-story buildings, including conventional buildings, LRB-based isolated buildings and building with seesaw structure, equipped with a newly introduced type of structural fuses, their seismic performances have been compared through nonlinear time history analyses (NLTHA). The employed fuses in seesaw buildings are a specific type of yielding plate dampers, called Multiple Curved Yielding Plate Energy Dissipater (MCYPED), installed at the bottom of the all circumferential columns of the lowest story of the building. To show the efficiency of the proposed seesaw system in comparison with other two mentioned groups, first, by finite element modeling, verified by experimental results, the initial and secondary stiffness values as well as the yielding and ultimate strengths of the MCYPEDs have been obtained to be modeled by multi-linear plastic springs in the seesaw buildings. Then, a series of NLTHA have been performed on the three groups of buildings by using a set of selected earthquakes. The compared responses include roof displacement and acceleration, base shear, inter-story drift and finally plastic hinges (PHs) formed in the building’s structures. Results show that the proposed seesaw building equipped with MCYPEDs not only results in lower seismic demand, similar to base isolation system, but also leads to remarkable energy dissipation capacity in the building structure at base level, so that the building structure remains basically elastic, and does not need any major repair work, even after large earthquakes, contrary to the conventional building which need to be demolished after the earthquake.

scholarly journals Seismic Vibration Control of Building with Lead Rubber Bearing Isolator

10.29007/pvzx ◽  
2018 ◽  
Author(s):  
Kishan Bhojani ◽  
Vishal Patel ◽  
Snehal Mevada
Keyword(s):  
Seismic Response ◽  
Base Isolation ◽  
Time History ◽  
Dynamic Parameter ◽  
Base Shear ◽  
Maximum Displacement ◽  
Maximum Acceleration ◽  
Isolation System ◽  
Loma Prieta Earthquake ◽  
Base Isolation System

During the life span of structure there may be an effect of vibration. Due to vibration there may be major or minor damage in building. Base isolation is best method to reduce the seismic response of the structure. This paper gives idea about base isolation system which can be used in multi-story building to reduce seismic response of the structure. This paper represents the initialize study of dynamic parameter like effective damping for four earthquake time history. In this paper the optimum effective damping has been found out under the effect of Loma Prieta earthquake time history. The parametric study has been conducted to evaluate the effect on maximum displacement, maximum acceleration, maximum base shear in bare frame and frame with isolator.

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