Soil-pile-structure interaction effects on seismic demands and fragility estimates of a typical Ontario highway bridge retrofitted with fiber reinforced elastomeric isolator

Un-bonded fiber reinforced elastomeric isolator (U-FREI) is light weight and facilitates easier installation in comparison to conventional steel reinforced elastomeric isolators (SREI), in which fiber layers are used as reinforcement to replace steel shims as are normally used in conventional isolators. Shear modulus of elastomer has significant influence on the force-displacement relationship of U-FREI. However, a few studies investigated the effect of shear modulus on the horizontal behavior of prototype U-FREI in literature. In this study, effect of shear modulus on performance of prototype U-FREIs is investigated by both experiment and finite element (FE) analysis. It is observed that reduction in horizontal stiffness of U-FREI with increasing horizontal displacement is due to both rollover deformation (or reduction in contact area of isolator with supports) and shear modulus of elastomer. Reasonable agreement is observed between the findings from experiment and FE analysis. Keywords: base isolator; prototype un-bonded fiber reinforced elastomeric isolator; rollover deformation; shear modulus; cyclic test.

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Seismic Response Analysis of RCC Frame Building using FREI

International Journal of Innovative Technology and Exploring Engineering - Special Issue ◽

10.35940/ijitee.j7447.0891020 ◽

2020 ◽

Vol 9 (10) ◽

pp. 118-125

Keyword(s):

Seismic Response ◽

Base Isolation ◽

Response Spectrum ◽

Research Work ◽

Thin Plates ◽

Response Analysis ◽

Fiber Reinforced ◽

Frame Building ◽

Elastomeric Isolator ◽

Fiber Reinforced Elastomeric Isolator

An analysis is given for the medium-rise building with fixed base and other with base isolation device. The device hereby used for base isolation is Fiber-reinforced Elastomeric Isolator (FREI). The Fiber-reinforced Elastomeric Isolator is an isolator which uses fiber fabric material instead of steel thin plates. The main purpose of using FREI is to analyze the seismic response of medium-rise RCC frame building. As in past many research work have been carried out for low-rise building. Therefore, in this paper (G+4), (G+6), (G+8) Storey building are taken for study and analysis has been demonstrated using commercial software ETABS v17. The design of Fiber Reinforced Elastomeric Isolators is broadly based on the guidelines of ASCE 7-10. The response spectrum analysis of different storey are based on Indian Design Standard. In addition to the design of FREI, a comparison between fixed based and base isolated RCC frame building has been carried out in the form of time period, displacement, drift at various load combination. The above parameter is taken to check whether it can withstand the loads and seismic forces without any failure.

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Modeling and Evaluation of a Seismically Isolated Bridge Using Unbonded Fiber-Reinforced Elastomeric Isolators

Earthquake Spectra ◽

10.1193/072416eqs118m ◽

2018 ◽

Vol 34 (1) ◽

pp. 145-168 ◽

Cited By ~ 3

Author(s):

Yasser M. Al-Anany ◽

Mohamed A. Moustafa ◽

Michael J. Tait

Keyword(s):

Low Cost ◽

Residual Deformation ◽

Accelerated Bridge Construction ◽

Fiber Reinforced ◽

Base Shear ◽

Elastomeric Bearing ◽

Elastomeric Isolator ◽

Seismically Isolated Bridge ◽

Fiber Reinforced Elastomeric Isolator ◽

Isolated Bridge

An unbonded fiber-reinforced elastomeric isolator (U-FREI) is a relatively new type of elastomeric bearing that can be implemented as a seismic isolator for bridges. U-FREIs possess beneficial characteristics, including their potentially low-cost and light-weight construction. Individual U-FREIs can be rapidly produced as they can be easily cut from large sheets to the required size and shape, which is an attractive feature for accelerated bridge construction. The objectives of this paper are to introduce a noniterative analytical model to simulate the lateral response of U-FREI, and then to utilize the model to investigate the seismic response of a typical highway bridge isolated using U-FREI and compare it with a traditional non-isolated bridge. The isolated bridge demonstrated a resilient seismic behavior where all the bridge components remained elastic with no damage or residual deformation. The analytical results indicate that the seismic demand of the isolated bridge is reduced by up to 77% and 84% in terms of base shear and accelerations, respectively, as compared with the non-isolated bridge.

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Predicting Stability of a Prototype Unbonded Fiber-Reinforced Elastomeric Isolator by Finite Element Analysis

International Journal of Computational Methods ◽

10.1142/s0219876220500152 ◽

2020 ◽

Vol 17 (10) ◽

pp. 2050015

Author(s):

Thuyet Van Ngo ◽

Anjan Dutta ◽

Sajal Kanti Deb

Keyword(s):

Finite Element ◽

Horizontal Displacement ◽

Fe Analysis ◽

Vertical Load ◽

Total Thickness ◽

Fiber Reinforced ◽

Element Analysis ◽

Elastomeric Isolator ◽

Fiber Reinforced Elastomeric Isolator ◽

Force Displacement

Unbonded fiber-reinforced elastomeric isolator (U-FREI) is an improved device for seismic mitigation of low-rise buildings. The horizontal force — displacement behavior of U-FREI is nonlinear due to rollover deformation and the horizontal stiffness is a function of both vertical load and horizontal displacement. In this paper, stability of a prototype U-FREI is studied based on the dynamic response utilizing finite element (FE) analysis. Furthermore, the horizontal response of the isolator is also evaluated under the design vertical load and increasing horizontal displacement up to [Formula: see text] [Formula: see text] is the total thickness of rubber layers) to observe the rollout instability.

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