Effect of Vertical Component of Earthquake on the Response of Pure-Friction Base-Isolated Structures

2013 ◽  
Vol 743 ◽  
pp. 105-109
Author(s):  
Wei Gu ◽  
Xiao Dong Wen ◽  
Wei Cai ◽  
Bin Liu
Keyword(s):  
Base Isolation ◽  
Vertical Component ◽  
Frictional Coefficient ◽  
Equation Of Motion ◽  
Masonry Structure ◽  
Dynamic Responses ◽  
Earthquake Intensity ◽  
Maximum Displacement ◽  
Isolation System ◽  
Base Isolation System

The objective of this research is to investigate the dynamic responses of the masonry structure with base-isolation system under the vertical earthquake. Through inter-story shear model with the multi-degree of freedom, the equation of motion and the distinguishing rule between slide and joggle were established. The effects of vertical component of earthquake on the response of pure-friction base-isolated structure were analyzed. Results show that the inter-story displacement, inter-story shear force and acceleration at lower layers are increased, but the response value at topper layers and the maximum displacement at isolated layer are less affected. The maximum displacement at isolated layer is mainly affected by frictional coefficient, sort condition and earthquake intensity.

scholarly journals Estimation of base isolated structure responses

1978 ◽  
Vol 11 (4) ◽  
pp. 234-244 ◽  
Author(s):  
D. M. Lee ◽  
I. C. Medland
Keyword(s):  
Base Isolation ◽  
Response Spectrum ◽  
Dynamic Responses ◽  
Elastic Response ◽  
Least Squares Regression ◽  
Maximum Displacement ◽  
Isolation System ◽  
Earthquake Parameters ◽  
Wide Range ◽  
Base Isolation System

The dynamic responses of a set of elastic six storey shear structures mounted on a bilinear hysteretic Base Isolation (B.I.) System and forced by a wide range of different 'types’ and 'strengths’ of real and simulated earthquakes, are studied. The responses of the same set of structures, without the Base Isolation System, to the same range of earthquakes are also computed for comparative purposes. It is found that for the B.I. system investigated, not only are
the maximum shear forces in an isolated structure reduced to, on average, 0.2 of their values without B.I., but also that the maximum shear responses of isolated structures can be closely estimated from a wide variety of different parameters, selected from ground motion and elastic response spectrum data of the forcing earthquakes. Ninety-five percent confidence intervals are determined for the linear least squares regression relations between structure responses and earthquake parameters. For the isolation system considered the maximum displacement across the isolation system during an earthquake is shown to be very closely correlated with the maximum structure shear force.

scholarly journals Influence of Elastomeric Bearings in Tension on the Seismic Performance of Base-Isolated r.c. Buildings

2020 ◽  
Vol 11 (1) ◽  
pp. 82
Author(s):  
Fabio Mazza ◽  
Mirko Mazza
Keyword(s):  
Base Isolation ◽  
Nonlinear Models ◽  
Vertical Component ◽  
Computer Code ◽  
Nonlinear Phenomena ◽  
Isolation System ◽  
Elastomeric Bearings ◽  
Near Fault ◽  
Base Isolation System ◽  
Near Fault Earthquakes

Elastomeric bearings are commonly used in base-isolation systems to protect the structures from earthquake damages. Their design is usually developed by using nonlinear models where only the effects of shear and compressive loads are considered, but uncertainties still remain about consequences of the tensile loads produced by severe earthquakes like the near-fault ones. The present work aims to highlight the relapses of tension on the response of bearings and superstructure. To this end, three-, seven- and ten-storey r.c. framed buildings are designed in line with the current Italian seismic code, with a base-isolation system constituted of High-Damping-Rubber Bearings (HDRBs) designed for three values of the ratio between the vertical and horizontal stiffnesses. Experimental and analytical results available in literature are used to propose a unified nonlinear model of the HDRBs, including cavitation and post-cavitation of the elastomer. Nonlinear incremental dynamic analyses of the test structures are carried out using a homemade computer code, where other models of HDRBs considering only some nonlinear phenomena are implemented. Near-fault earthquakes with comparable horizontal and vertical components, prevailing horizontal component and prevailing vertical component are considered as seismic input. Numerical results highlight that a precautionary estimation of response parameters of the HDRBs is attained referring to the proposed model, while its effects on the nonlinear response of the superstructure are less conservative.

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.

Study on Vertical Component Seismic Isolation System With Coned Disk Spring

2004 ◽  
Author(s):  
S. Kitamura ◽  
M. Morishita ◽  
S. Moro
Keyword(s):  
Seismic Isolation ◽  
Base Isolation ◽  
Vertical Component ◽  
Reactor Vessel ◽  
Full Scale ◽  
Fast Reactors ◽  
Isolation System ◽  
Disk Spring ◽  
Structural Concept ◽  
Base Isolation System

A structural concept of a vertical component isolation system for fast reactors, assuming a building adopting a horizontal base isolation system, has been studied. In this concept, a reactor vessel and major primary components are suspended from a large common deck supported by isolation devices consisting of large coned disk springs. The outline of the vertical component seismic isolation system and a series of model tests with full scale coned disk spring and damper are shown in this paper.

scholarly journals Design Method of Vertical Component Isolation System

2002 ◽  
Author(s):  
S. Kitamura ◽  
M. Morishita
Keyword(s):  
Base Isolation ◽  
Design Method ◽  
Vertical Component ◽  
Reactor Vessel ◽  
Isolation System ◽  
Structural Concept ◽  
Base Isolation System ◽  
Series Of Experiments ◽  
Isolation Device

A structural concept of a vertical component isolation system for fast reactors, assuming a building adopting a horizontal base isolation system, has been studied. In this concept, a reactor vessel and major primary components are suspended from a large common deck supported by isolation devices consisting of large coned disk springs. A series of experiments using a simple model for the confirmation of the isolation effect, and a case study of vertical isolation device and plant layout are shown in this paper.

Hysteresis Loops of Base Isolation System - An Overview

2021 ◽  
Vol 879 ◽  
pp. 189-201
Author(s):  
M.A. Amir ◽  
N.H. Hamid
Keyword(s):  
Earthquake Engineering ◽  
Structural Damage ◽  
Base Isolation ◽  
Numerical Models ◽  
Hysteresis Loops ◽  
Human Beings ◽  
Rc Buildings ◽  
Isolation System ◽  
Base Isolation System ◽  
Isolation Systems

Recently, there are a lot of technological developments in the earthquake engineering field to reduce structural damage and one of them is a base isolation system. The base isolation system is one of the best technologies for the safety of human beings and properties under earthquake excitations. The aim of this paper is to review previous research works on simulation of base isolation systems for RC buildings and their efficiency in the safety of these buildings. Base isolation decouples superstructure from substructure to avoid transmission of seismic energy to the superstructure of RC buildings. The most effective way to assess the base isolation system for RC building under different earthquake excitations is by conducting experiment work that consumes more time and money. Many researchers had studied the behavior of base isolation system for structure through modeling the behavior of the base isolation in which base isolator is modeled through numerical models and validated through experimental works. Previous researches on the modeling of base isolation systems of structures had shown similar outcomes as the experimental work. These studies indicate that base isolation is an effective technology in immunization of structures against earthquakes.

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.

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