A new statistical equation for predicting nonlinear time history displacement of seismic isolation systems

Structures ◽  
2020 ◽  
Vol 24 ◽  
pp. 177-190 ◽  
Author(s):  
Nhan D. Dao ◽  
Hieu Nguyen-Van ◽  
Tuan H.A. Nguyen ◽  
Ai B. Chung
Keyword(s):  
Seismic Isolation ◽  
Time History ◽  
Statistical Equation ◽  
Isolation Systems ◽  
Nonlinear Time History ◽  
Seismic Isolation Systems

Evaluation of Simplified Methods for the Design of Bridges with Seismic Isolation Systems

2009 ◽  
Vol 25 (2) ◽  
pp. 221-238 ◽  
Author(s):  
Donatello Cardone ◽  
Mauro Dolce ◽  
Giuseppe Palermo
Keyword(s):  
Seismic Isolation ◽  
Time History ◽  
Single Mode ◽  
Analysis And Design ◽  
Strongly Nonlinear ◽  
Mode Method ◽  
Proper Design ◽  
Isolation Systems ◽  
Nonlinear Time History ◽  
Seismic Isolation Systems

In this paper, simplified methods for the design of bridges equipped with strongly nonlinear isolation systems (IS) are examined. Reference is made to the single mode method (SMM), adopted in many seismic codes and guidelines for the analysis and design of bridges with flexible substructure. Two different design approaches are considered, one aimed at controlling the maximum force transmitted by the IS to the pier, while the other the maximum pier-deck displacement. The background of the SMM and the implementation of the two design approaches are presented first. This is followed by a series of examples of application and validation studies through nonlinear time-history analyses (NTHA). The variability of the mechanical behavior of the IS with air temperature is taken into account in both design procedures and NTHA. The NTHA results point out that simplified methods of analysis can be reliably used for bridges with IS, to satisfy the design performance objectives over the whole operation range of temperature, once a proper design temperature is selected.

Development of an Evaluation Method for Seismic Isolation Systems of Nuclear Power Facilities: Part 2 — Application of CCFS Method to the Multiply Supported Systems

2014 ◽  
Author(s):  
Koichi Tai ◽  
Keisuke Sasajima ◽  
Shunsuke Fukushima ◽  
Noriyuki Takamura ◽  
Shigenobu Onishi
Keyword(s):  
Power Plant ◽  
Nuclear Power ◽  
Seismic Isolation ◽  
Evaluation Method ◽  
Time History ◽  
Piping System ◽  
History Analysis ◽  
Piping Systems ◽  
Isolation Systems ◽  
Seismic Isolation Systems

This paper provides a part of series of “Development of an Evaluation Method for Seismic Isolation Systems of Nuclear Power Facilities”. Paper is focused on the seismic evaluation method of the multiply supported systems, as the one of the design methodology adopted in the equipment and piping system of the seismic isolated nuclear power plant in Japan. Many of the piping systems are multiply supported over different floor levels in the reactor building, and some of the piping systems are carried over to the adjacent building. Although Independent Support Motion (ISM) method has been widely applied in such a multiply supported seismic design of nuclear power plant, it is noted that the shortcoming of ignoring correlations between each excitations is frequently misleaded to the over-estimated design. Application of Cross-oscillator, Cross-Floor response Spectrum (CCFS) method, proposed by A. Asfura and A. D. Kiureghian[1] shall be considered to be the excellent solution to the problems as mentioned above. So, we have introduced the algorithm of CCFS method to the FEM program. The seismic responses of the benchmark model of multiply supported piping system are evaluated under various combination methods of ISM and CCFS, comparing to the exact solutions of Time History analysis method. As the result, it is demonstrated that the CCFS method shows excellent agreement to the responses of Time History analysis, and the CCFS method shall be one of the effective and practical design method of multiply supported systems.

Development of an Evaluation Method for Seismic Isolation Systems of Nuclear Power Facilities: Part 3 — Seismic Response of Crossover Piping for Seismic Isolation System

2014 ◽  
Author(s):  
Akihito Otani ◽  
Teruyoshi Otoyo ◽  
Hideo Hirai ◽  
Hirohide Iiizumi ◽  
Hiroshi Shimizu ◽  
...  
Keyword(s):  
Seismic Response ◽  
Nuclear Power ◽  
Seismic Isolation ◽  
Evaluation Method ◽  
Response Spectrum ◽  
Time History ◽  
Response Analysis ◽  
Isolation System ◽  
Isolation Systems ◽  
Seismic Isolation Systems

This paper, which is part of the series entitled “Development of an Evaluation Method for Seismic Isolation Systems of Nuclear Power Facilities”, shows the linear seismic response of crossover piping installed in a seismically isolated plant. The crossover piping, supported by both isolated and non-isolated buildings, deforms with large relative displacement between the two buildings and the seismic response of the crossover piping is caused by two different seismic excitations from the buildings. A flexible and robust structure is needed for the high-pressure crossover piping. In this study, shaking tests on a 1/10 scale piping model and FEM analyses were performed to investigate the seismic response of the crossover piping which was excited and deformed by two different seismic motions under isolated and non-isolated conditions. Specifically, as linear response analysis of the crossover piping, modal time-history analysis and response spectrum analysis with multiple excitations were carried out and the applicability of the analyses was confirmed. Moreover, the seismic response of actual crossover piping was estimated and the feasibility was evaluated.

scholarly journals Inelastic demand spectra for bi-linear seismic isolation systems based on nonlinear time history analyses and the response of lead-rubber bearing isolation systems subjected to near-source ground motions

2007 ◽  
Vol 40 (1) ◽  
pp. 7-17 ◽  
Author(s):  
John X. Zhao ◽  
Jian Zhang
Keyword(s):  
Seismic Isolation ◽  
Ground Motions ◽  
Time History ◽  
Design Tool ◽  
Nonlinear Time History Analysis ◽  
Inelastic Demand ◽  
Isolated Structures ◽  
Seismically Isolated ◽  
Isolation Systems ◽  
Nonlinear Time History

In this study, we present an inelastic demand spectrum for the design of seismically-isolated structures using lead-rubber bearings or other types of isolators with bi-linear hysteresis loops and the inelastic spectrum can be used in the design of seismically-isolated structures in a very similar manner to capacity spectrum method. The inelastic demand spectrum is a very useful design tool for visual selection of optimal isolation parameters, and eliminates the use of equivalent linear-elastic substitute structures as the displacement demand is obtained from nonlinear time history analysis. The responses of seismically-isolated structures subjected to near-source ground motions with either large forward-directivity pulses or fault-fling pulses are presented. Our analyses suggest that seismic isolation can be used to protect structures subjected to recorded ground motions currently available to us, with acceptable levels of base shear coefficient and isolator displacement, except for one component of the TCU068 record from the 1999 Chichi, Taiwan, earthquake (which contained a large permanent displacement of nearly 10 m).

Analyses of Seismic Isolation Systems in Kyrgyzstan

2002 ◽  
Author(s):  
Tynymbek O. Ormonbekov ◽  
Ulugbek T. Begaliev
Keyword(s):  
Active Zone ◽  
Seismic Isolation ◽  
Seismic Protection ◽  
Kyrgyz Republic ◽  
Isolation Systems ◽  
Seismic Isolation Systems

The purpose of the present work is the analysis of existing methods of seismoisolation in the Kyrgyz Republic at which 95% of territory has seismically active zone with intensity 8, 9 and more. Also an opportunity of application of system seismic protection as rubber-metal bearings.

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