The Experts below are selected from a list of 6435 Experts worldwide ranked by ideXlab platform
Ke Hill - One of the best experts on this subject based on the ideXlab platform.
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Development and Testing of a Pivotal Rocking Seismic Isolation System
1996Co-Authors: Ke HillAbstract:Seismic Isolation is a design approach that aims to reduce the level of dynamic loading experienced by a structure during an earthquake. This paper details the development of an innovative pivotal rocking Seismic Isolation system involving ring springs for protecting columnar structures during earthquakes. The Isolation system is described and the hysteresis characteristics of the dampers it uses are presented. Results of experimental tests and computer modelling of the system, subjected to earthquake inputs, are reported. It is shown that the pivotal rocking Seismic Isolation system is effective in reducing structural loads during short period type earthquakes. Considerable potential exists for utilising these Isolation systems to protect a wide range of columnar structures during earthquakes.
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A Pivotal Rocking Seismic Isolation System for Protecting Columnar Structures During Earthquakes
1996Co-Authors: Ke HillAbstract:Seismic Isolation is a design approach that aims to reduce the level of dynamic loading experienced by a structure during an earthquake. This paper details the development of an innovative pivotal rocking Seismic Isolation system for protecting columnar structures during earthquakes. Initially, the Isolation system is described. Next, the hysteresis characteristics of dampers used with the Isolation system are presented. A Seismic Isolation system was manufactured and then subjected to shaker table inputs to determine the effectiveness of the system during earthquake excitations. Results of experimental testing and computer simulation analyses are reported. Experimental results for the isolated and unisolated systems are compared and it is shown that the pivotal rocking Seismic Isolation system is effective in reducing structural loads during short period type earthquakes. Considerable potential exists for utilising these Seismic Isolation systems to protect a wide range of columnar structures during earthquakes.
Victor A Zayas - One of the best experts on this subject based on the ideXlab platform.
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Seismic Isolation retrofit of large historic building
Journal of Structural Engineering-asce, 1996Co-Authors: Anoop Mokha, M. C. Constantinou, Navinchandra Amin, Victor A ZayasAbstract:Seismic Isolation in the United States is gaining wide acceptance as an attractive and alternate means to upgrade historic structures Seismically with minimal disturbance to architecturally significant features. One important historic-landmark structure that underwent such an upgrade is the Ninth Circuit U.S. Court of Appeals building located in San Francisco, which suffered damage during the 1989 Loma Prieta earthquake and was declared an unsafe building for further occupancy. The present paper summarizes the comprehensive approach adopted for implementation of the Seismic-Isolation technique for the Seismic retrofit of this monumental structure. This historically significant structure is the first federal building to be retrofitted using Seismic Isolation. The paper discusses in detail the procedure adopted for evaluating the existing building strength, establishing the design approach, and evaluating and selecting the optimum isolator placement location and Isolation system best suited for the building...
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a simple pendulum technique for achieving Seismic Isolation
Earthquake Spectra, 1990Co-Authors: Victor A Zayas, Stephen A MahinAbstract:Abstract An innovative Seismic Isolation system, the Friction Pendulum System (FPS), offers improvements in strength, versatility and ease of installation as compared to previous systems. Moreover, the approach offers several inherent performance benefits not available before. The FPS uses geometry and gravity to achieve the desired Seismic Isolation results. It is based on well known engineering principles of pendulum motion, and is constructed of materials with demonstrated longevity and resistance to environmental deterioration. The desirable Isolation characteristics exhibited by FPS components hold the promise of an effective and practical system for significantly increasing the Seismic resistance of new and existing buildings. This paper summarizes results of a comprehensive research and testing program to assess the technical performance of the FPS. In addition, an example building design using the FPS is given.
M. C. Constantinou - One of the best experts on this subject based on the ideXlab platform.
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performance of Seismic Isolation hardware under service and Seismic loading
2007Co-Authors: M. C. Constantinou, Andrew S Whittaker, Y Kalpakidis, Daniel M Fenz, Gordon P WarnAbstract:This report presents a comprehensive description of the current state of knowledge on the behavior of hardware used in Seismic Isolation and in Seismic damping systems. Particular emphasis is placed on the description of fundamental behavior under both non-Seismic, service-type loading conditions and under high-speed Seismic conditions. Specific problems described and addressed in this report include the following: (1) aging of elastomeric and sliding bearings; (2) effect of ambient temperature on the behavior of elastomeric and sliding bearings; (3) prediction and experimental verification of effects of frictional heating on the sliding bearings; (4) prediction and experimental verification of effects of hysteric heating on the lead-rubber bearings; (5) analysis of elastomeric and sliding bearings; (6) design of elastomeric and sliding bearings based on principles of LRFD and ASD; (7) establishment of upper and lower bound values of properties of Seismic Isolation bearings for use in the analysis and design; and (8) detailed new testing protocols for Seismic isolators and dampers. The presented information may represent the basis for the development of contemporary Guide Specifications for Seismic Isolation Design.
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Seismic Isolation of highway bridges
2006Co-Authors: Ian G. Buckle, M. C. Constantinou, Mirat Diceli, Hamid GhasemiAbstract:More than 200 bridges have been designed or retrofitted in the United States using Seismic Isolation in the last 20 years, and more than a thousand bridges around the world now use this cost-effective technique for Seismic protection. Intended to supplement AASHTO’s Guide Specifications for Seismic Isolation Design (1999), this manual presents the principles of Isolation for bridges, develops step-by-step methods of analysis, explains material and design issues for elastomeric and sliding isolators, and gives detailed examples of their application to standard highway bridges. Design guidance is given for the lead-rubber isolator, the friction-pendulum isolator, and the Eradiquake isolator, all of which are found in use today in the United States. Guidance on the development of test specifications for these isolators is also given.
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Seismic Isolation retrofit of large historic building
Journal of Structural Engineering-asce, 1996Co-Authors: Anoop Mokha, M. C. Constantinou, Navinchandra Amin, Victor A ZayasAbstract:Seismic Isolation in the United States is gaining wide acceptance as an attractive and alternate means to upgrade historic structures Seismically with minimal disturbance to architecturally significant features. One important historic-landmark structure that underwent such an upgrade is the Ninth Circuit U.S. Court of Appeals building located in San Francisco, which suffered damage during the 1989 Loma Prieta earthquake and was declared an unsafe building for further occupancy. The present paper summarizes the comprehensive approach adopted for implementation of the Seismic-Isolation technique for the Seismic retrofit of this monumental structure. This historically significant structure is the first federal building to be retrofitted using Seismic Isolation. The paper discusses in detail the procedure adopted for evaluating the existing building strength, establishing the design approach, and evaluating and selecting the optimum isolator placement location and Isolation system best suited for the building...
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Seismic Isolation Development in Europe
Passive and Active Structural Vibration Control in Civil Engineering, 1994Co-Authors: M. C. ConstantinouAbstract:This section presents a brief account of the development and application of Seismic (or base) Isolation in Europe. It appears that the first documented attempts to mitigate Seismic hazard by Seismic Isolation were made in Europe.
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Seismic Isolation Development in U.S.: Case Studies
Passive and Active Structural Vibration Control in Civil Engineering, 1994Co-Authors: M. C. ConstantinouAbstract:This section describes the development and application of Seismic (or base) Isolation in the United States. Significant strides have been made in the implementation of the technology. This is attributed to recent advances in Seismic Isolation hardware and the removal of a number of impediments, which delayed widespread implementation in the near past.
Zhou Qian - One of the best experts on this subject based on the ideXlab platform.
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Seismic Isolation of SMA-rubber Bearings in Spatial Lattice Shells
Journal of Beijing Polytechnic University, 2020Co-Authors: Zhou QianAbstract:In order to reduce the Seismic damages of long span roofs, the Seismic Isolation bearings are used. A new type of SMA-rubber bearing is designed by incorporating shape memory alloy (SMA) with ordinary laminated rubber pads. A mechanical model of the bearing is set up. Then, the new bearing is applied to lattice shell structures to investigate its Seismic Isolation performance for spatial structures. Seismic Isolation equations for spatial lattice shells are derived. Through analyses on a single-layer cylindrical lattice shell, it is shown that Seismic responses of lattice shell structures can be effectively reduced by using SMA-rubber bearings. The study also indicates that the developed SMA-rubber bearing provides superior performance than ordinary rubber bearing.
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Seismic Isolation performance and design of a SMA-rubber composite bearing
World Earthquake Engineering, 2020Co-Authors: Zhou QianAbstract:By utilizing hysteretic damping capacity resulting from superelastic deformation of shape memory alloy,a new type of SMA-rubber composite bearing is designed.A mechanical model is established and the Seismic Isolation performance of the bearing is investigated.It is shown that the proposed SMA-rubber composite bearing provides more excellent Seismic Isolation performance than ordinary rubber bearings.
W. H. Robinson - One of the best experts on this subject based on the ideXlab platform.
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Seismic Isolation of civil buildings in New Zealand
Progress in Structural Engineering and Materials, 2020Co-Authors: W. H. RobinsonAbstract:In New Zealand, Seismic Isolation, the technique in which the structure is decoupled from earthquake-induced ground motions, has now advanced to the point where it is often considered for the protection of both new and existing buildings, bridges, and industrial plant. The Seismically isolated buildings fall into two broad categories—fragile structures of historic significance and new structures with contents which need to be protected. In this paper we briefly describe the principles of Seismic Isolation and discuss some of the Isolation systems available before giving some examples of the application of Seismic Isolation to buildings in New Zealand.
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Recent research and applications of Seismic Isolation in New Zealand
Bulletin of the New Zealand National Society for Earthquake Engineering, 1995Co-Authors: W. H. RobinsonAbstract:In New Zealand, Seismic Isolation, the technique in which the structure is decoupled from earthquake-induced ground motions, has now advanced to the point where it is often considered for the protection of both new and existing buildings, bridges, and to a lesser extent, industrial plant. Many of the devices used in these applications have been developed in our laboratory. We describe here how the lead-based devices operate, and we give some examples of the application of Seismic Isolation to structures in New Zealand. Current interest is focused on the application of Seismic Isolation to three buildings in central Wellington. In July 1993, the construction of the Seismically isolated Museum of New Zealand was started on the Wellington waterfront. All of the lead-rubber isolators have now been tested and installed. Nearby the NZ Parliament Building and Library have been retrofitted with a lead-rubber bearing system. To support the continuation of improvements to the Seismic resistance of structures a number of research programs are operating in the Universities of Auckland and Canterbury, the Engineering Seismology Section of the NZ Institute of Geological and Nuclear Sciences, Works, a number of engineering consultants and in our company. Very strong support for the principles of Seismic Isolation is given by the fact that of the ten hospitals affected by the 1994 Northridge earthquake in Los Angeles, only the hospital Seismically isolated by a lead-rubber bearing system was able to continue to operate. Further support is given by the excellent behaviour of two isolated buildings in the 1995 Hyogo Ken-Nanbu earthquake).
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Seismic Isolation in New Zealand
Nuclear Engineering and Design, 1991Co-Authors: R. I. Skinner, W. H. Robinson, G. H. McverryAbstract:Bridges, buildings, and industrial equipment can be given increased protection from earthquake damage by limiting the earthquake attack through Seismic Isolation. A broad summary of the Seismic responses of base-isolated structures is of considerable assistance for their preliminary design. Seismic Isolation as already used in New Zealand consists of a flexible base or support combined with some form of energy-dissipating device, usually involving the hysteretic working of steel or lead. This paper presents examples of the New Zealand experience, where Seismic Isolation has been used for 42 bridges, 3 buildings, a tall chimney, and high-voltage capacitor banks. Additional Seismic response factors, which may be important for nuclear power plants, are also discussed briefly. © 1991.