scholarly journals Responses of Building Base Isolated With High Damping Rubber Bearings

2019 ◽  
Vol 8 (9) ◽  
pp. 1287-1292
Keyword(s):  
Seismic Isolation ◽  
Design Procedure ◽  
Hysteretic Model ◽  
Base Shear ◽  
Ground Acceleration ◽  
Element Analysis ◽  
High Damping Rubber Bearings ◽  
Fixed Base ◽  
High Damping Rubber ◽  
Rubber Bearings

Seismic isolation is one of the most efficient techniques to protect structures against earthquakes. Rubber bearings are suitable for low-rise and medium-rise buildings due to its durability and easy fabrication. This paper presents the hori-zontal response of a six-storey base-isolated building using high damping rubber bearings (HDRB) under two ground motions of earthquakes as types I and II in JRA (2002) by finite element analysis. In this analysis, these bearings are mod-elled by the bilinear hysteretic model which is indicated in JRA and AASHTO. Comparison of horizontal response including base shear force and roof level acceleration between the two cases: base-isolated building and fixed-base building is carried out to evaluate the effectiveness of the use of HDRB on the protection of buildings from earthquakes. The numerical results show that the peak value of roof floor acceleration of the fixed-base building is two times higher than that of the base-isolated building, and the floor accelerations depend on the peak values of ground acceleration. In addition, the step-by-step design procedure for deter-mining the size of HDRBs used for buildings is also presented in this paper.

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.

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.

On the Effectiveness of Two Isolation Systems for the Seismic Protection of Elevated Tanks

2015 ◽  
Vol 137 (3) ◽  
Author(s):  
Fabrizio Paolacci
Keyword(s):  
Time History ◽  
Seismic Protection ◽  
Base Shear ◽  
Lumped Mass ◽  
High Damping Rubber Bearings ◽  
Elevated Tanks ◽  
High Damping Rubber ◽  
Isolation Systems ◽  
The Stability ◽  
Rubber Bearings

This paper deals with the effectiveness of two isolation systems for the seismic protection of elevated steel storage tanks. In particular, the performance of high damping rubber bearings (HDRB) and friction pendulum isolators (FPS) has been analyzed. As case study, an emblematic example of elevated tanks collapsed during the Koaceli Earthquake in 1999 at Habas pharmaceutics plant in Turkey is considered. A time-history analysis conducted using lumped mass models demonstrates the high demand in terms of base shear required to the support columns and their inevitable collapse due to the insufficient shear strength. A proper design of HDRB and FPS isolator according to the EN1998 and a complete nonlinear analysis of the isolated tanks proved the high effectiveness of both isolation systems in reducing the response of the case tank. Actually, the stability conditions imposed by the code and a reduced level of convective base shear obtained with the second isolation typology suggests the use of FPS isolators rather than HDRB devices.

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