Seismic Rehabilitation of the Mackay School of Mines, Phase III, with Base Isolation

1990 ◽  
Vol 6 (2) ◽  
pp. 297-308 ◽  
Author(s):  
Douglas Way ◽  
Jack Howard
Keyword(s):  
Base Isolation ◽  
Unreinforced Masonry ◽  
Point Of View ◽  
Phase Iii ◽  
Isolation System ◽  
Seismic Rehabilitation ◽  
The North ◽  
Historic Monument ◽  
High Damping Rubber ◽  
Rubber Bearings

The original Mackay School of Mines Building was constructed in 1908. It is one of the original buildings of the University of Nevada, and is situated at the north end of the main quadrangle within the campus. Prominent in its location at University of Nevada and in appearance, the building is designated as a national historic monument. During the years of 1926 and 1956, significant structural alterations were made to the original building. Phase III work at the original Mackay School of Mines Building involves adding a library at the basement, with the balance of the building being remodeled for similar-type functions. Constructed mainly of unreinforced masonry, the seismic rehabilitation of the structure warrants careful attention. During the schematic phase of the work, both conventional strengthening and Base Isolation were explored as potential techniques with which to mitigate damage from earthquakes. Cost estimate of both schemes were also developed. From a preservationist point of view, there were definite advantages in the isolation design. Since the isolation system could filter out most of the damaging forces associated with earthquakes, none of the unreinforced masonry walls required strengthening. As a result, many of the original architectural features of the original building can be salvaged, maintaining the original quality of the building and its identity. For these reasons the Base Isolation option was selected as the seismic retrofit scheme. This paper illustrates the Base Isolation design for the Mackay School of Mines, a historical structure constructed of unreinforced masonry. The isolation system consists of high-damping rubber bearings in combination with sliding elements.

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.

scholarly journals Pengaruh Penggunaan Base Isolation High Damping Rubber Bearing Pada Struktur Beton Bertulang

2020 ◽  
Vol 6 (2) ◽  
pp. 181-194
Author(s):  
Syahnandito ◽  
Reni Suryanita ◽  
Ridwan
Keyword(s):  
Base Isolation ◽  
Isolation System ◽  
Rubber Bearing ◽  
High Damping Rubber Bearing ◽  
Base Isolator ◽  
Base Isolation System ◽  
High Damping Rubber

Salah satu cara yang dapat dilakukan adalah menggunakan peredam beban gempa dengan sistem isolasi dasar (base isolation system). Penggunaan base isolation system  pada bangunan dapat mengisolasi perambatan getaran akibat gempa dari tanah ke struktur atas bangunan menggunakan komponen berbahan karet. Tujuan penelitian ini adalah untuk menganalisis pengaruh penggunaan sistem isolasi dasar berupa High Damping Rubber Bearing pada periode dan gaya geser dasar  struktur beton bertulang. Objek penelitian adalah bangunan hotel 15 lantai dengan ketinggian 62,9 m. Penelitian diawali dengan pemodelan struktur menggunakan aplikasi ETABS v2016 sehingga didapatkan periode dan gaya geser dasar struktur fixbase. Tahap selanjutnya memberikan gaya pada model struktur dengan isolasi dasar High Dumper Rubber Bearing sehingga didapatkan periode dan gaya geser dasar struktur dengan base isolator. Hasil analisis pada struktur fixbase didapatkan periode sebesar 4,212 detik, dengan gaya geser dasar didapatkan sebesar 1470,725 ton. Sedangkan hasil analisis pada struktur dengan base isolator didapatkan periode sebesar 5,500 detik, dengan gaya geser dasar didapatkan sebesar 1286,071 ton. Maka dapat disimpulkan bahwa pada struktur dengan base isolator terjadi peningkatan periode sebesar 30,58 %, sedangkan gaya geser dasar terjadi penurunan 12,56 %.

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

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

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.

Analysis and Demonstrative Application of a Base Isolation/Supplemental Damping Technology

2008 ◽  
Vol 24 (3) ◽  
pp. 775-793 ◽  
Author(s):  
Stefano Sorace ◽  
Gloria Terenzi
Keyword(s):  
Base Isolation ◽  
Numerical Models ◽  
Ground Acceleration ◽  
Fixed Base ◽  
Supplemental Damping ◽  
And Performance ◽  
High Damping Rubber ◽  
Design Earthquake ◽  
Rubber Bearings ◽  
The Cost

As a concluding step of several studies on a special base isolation/supplemental damping system, where pressurized fluid viscous spring-dampers are coupled to steel-Teflon sliders, the system was applied for the first time to a demonstrative strategic building in Italy. A final experimental campaign was developed to assess the interference of the dissipative actions of the two component devices. The campaign confirmed the linear additive combination implicitly assumed in relevant numerical models. The design and performance evaluation analyses performed on the building showed that maximum base displacements were only just below 45 mm, for the basic design earthquake level. As a result, very simple joints for all the facilities were used. For the same earthquake level, reduction factors of 2.48 and 2.12 on the superstructure response accelerations were obtained for the two main directions in plan as compared to peak ground acceleration. Low base displacement values, and a totally elastic superstructure response also emerged for the maximum earthquake level considered, as well as for the most demanding Italian historical near-fault ground motions introduced as inputs in the final verification analyses. The cost of the building structure resulted to be around 10% lower than the cost of a fixed-base traditional design, as well as of a base isolated structure incorporating high damping rubber bearings.

Design of Shape Memory Alloy Damper for Base Isolated Structure

1997 ◽  
Author(s):  
Krzysztof Wilde ◽  
Paolo Gardoni ◽  
Yozo Fujino ◽  
Stefano Besseghini
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Base Isolation ◽  
Hysteretic Behavior ◽  
Isolation System ◽  
Rubber Bearing ◽  
Laminated Rubber Bearing ◽  
Base Isolation System ◽  
Rubber Bearings ◽  
Smart Base Isolation

Abstract Base isolation provides a very effective passive method of protecting the structure from the hazards of earthquakes. The proposed isolation system combines the laminated rubber bearing with the device made of shape memory alloy (SMA). The smart base isolation uses hysteretic behavior of SMA to increase the structural damping of the structure and utilizes the different responses of the SMA at different levels of strain to control the displacements of the base isolation system at various excitation levels. The performance of the smart base isolation is compared with the performance of isolation by laminated rubber bearings to assess the benefits of additional SMA damper for isolation of three story building.

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.

SILER Project: Design of the Seismic Isolators

2014 ◽  
Author(s):  
Alessandro Poggianti ◽  
Massimo Forni ◽  
Barbara Ferrucci ◽  
Riccardo Scipinotti ◽  
Didier De Bruyn ◽  
...  
Keyword(s):  
Nuclear Power ◽  
Seismic Isolation ◽  
Power Plants ◽  
Risk Mitigation ◽  
Vertical Direction ◽  
Design Solution ◽  
Isolation System ◽  
Standard Design ◽  
High Damping Rubber ◽  
Rubber Bearings

This paper describes the SILER (Seismic-Initiated event risk mitigation in LEad-cooled Reactors) Project results obtained so far in the design of the seismic isolation system of two nuclear power plants: the ELSY configuration for the LFR (Lead-Cooled Fast Reactor) design and the MYRRHA configuration for the accelerator-driven systems (ADS). The seismic protection of the nuclear buildings by means of seismic isolation has been chosen in order to minimize changes to the standard design of the civil works and internal components of the Nuclear Power Plant. The work led to the identification of the optimal design solution, in terms of type and location of seismic devices, to achieve compliance to the floor response acceleration spectra in horizontal and vertical direction, with levels of horizontal displacements not exceeding the maximum acceptable values for structural and non-structural elements. The isolators studied in the project are of the type elastomeric, both High Damping Rubber Bearings and Lead Rubber Bearings; moreover the adoption of a fail-safe system to limit the horizontal isolator deformation in case of beyond design earthquakes is studied.

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