Shaking Table Tests on a Spherical Tank Mock-Up Provided With Seismic Isolation and Flexible Piping Connections

2006 ◽  
Author(s):  
Massimo Forni ◽  
Alessandro Poggianti ◽  
Giulia Bergamo ◽  
Fabrizio Gatti
Keyword(s):  
Seismic Isolation ◽  
Shaking Table ◽  
Seismic Protection ◽  
Piping System ◽  
Fiber Reinforced ◽  
Shaking Table Tests ◽  
Fixed Base ◽  
High Damping Rubber ◽  
Isolation Systems ◽  
Rubber Bearings

The Project INDEPTH (Development of INnovative DEvices for Seismic Protection of PeTrocHemical Facilities), supported by the European Commission, has the objective of developing and applying innovative seismic isolation and/or dissipation systems for critical structures at petrochemical facilities. In the framework of INDEPTH, integrated seismic protection systems have been conceived, developed and tested. They are aimed at protecting liquid-filled structures (product storage, spherical and LNG tanks), with new devices (fiber-reinforced isolators, buckling reinforced braces) specific for each application and new flexible piping couplings, to compensate the displacements resulting from the use of isolation systems. The research program has been focused on the selection of critical structures, the design and manufacturing of the devices, the numerical assessment and the experimental validation through shaking table tests [1–4]. A quantification of technical/economical/safety benefits with respect to the conventional state-of-the-art measures presently adopted and potential application to retrofitting has been performed. This paper describes the validation through shaking table tests of the effectiveness of the isolation systems on a spherical mock-up and the related piping system equipped with flexible joints. Different configurations of the mock-up have been tested, such as: fixed base, isolated base with High Damping Rubber Bearings, Fiber Reinforced Rubber Bearings and Lead Rubber Bearings. Furthermore, each configuration has been tested for three different level of filling to verify the sloshing behavior in the sphere and the effectiveness of the isolation systems at filling levels different from the design one (full sphere).

Shaking Table Tests on a Spherical Tank Mock-Up Provided With Seismic Isolation and Flexible Piping Connections

2005 ◽  
Author(s):  
Massimo Forni
Keyword(s):  
Seismic Isolation ◽  
Shaking Table ◽  
Seismic Protection ◽  
Piping System ◽  
Fiber Reinforced ◽  
Shaking Table Tests ◽  
Time Histories ◽  
High Damping Rubber ◽  
Isolation Systems ◽  
Rubber Bearings

The Project INDEPTH (Development of INnovative DEvices for Seismic Protection of PeTrocHemical Facilities), supported by the European Commission, has the objective of developing and applying innovative seismic isolation and/or dissipation devices for critical structures at petrochemical facilities. In the framework of INDEPTH, integrated seismic protection systems have been conceived, developed and tested. They are aimed at protecting liquid-filled structures (product storage, spherical and LNG tanks), with new devices (fiber-reinforced isolators, buckling reinforced braces) specific for each application and new flexible piping couplings, to compensate the displacements resulting from the use of isolation systems. The research program has been focused on the selection of critical structures, the design and manufacturing of the devices, the numerical assessment and the experimental validation through shaking table tests. A quantification of technical/economical/safety benefits with respect to the conventional state-of-the-art measures presently adopted and potential application to retrofitting has been performed. Validation through shaking table tests of the effectiveness of the isolation systems on the spherical mock-up (Figure 1), and the related piping system equipped with flexible joints (Figure 2), had been performed. Two types of seismic input have been applied, both synthesized from the 5% damping spectra of EC8 (medium and soft soils); the target peak acceleration value of the time histories was 0.4 g. Different configurations of the mock-up have been tested, such as: fixed base, isolated base with High Damping Rubber Bearings, Fiber Reinforced Rubber Bearings and Lead Rubber Bearings. Furthermore, each configuration has been tested for both time histories and at three different level of filling to verify the sloshing behavior in the sphere and the effectiveness of the isolation systems at levels of filling different from the design one (full sphere). Comparison among all the above mentioned conditions could be done. The presentation will show the main results of the shaking table campaign.

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.

Shaking Table Tests With Large Test Specimens of Seismically Isolated FBR Plants: Part 2—Damage Test of Reinforced Concrete Wall Structure

2009 ◽  
Author(s):  
Satoru Inaba ◽  
Takuya Anabuki ◽  
Kazutaka Shirai ◽  
Shuichi Yabana ◽  
Seiji Kitamura
Keyword(s):  
Reinforced Concrete ◽  
Seismic Isolation ◽  
Shaking Table Test ◽  
Shaking Table ◽  
Wall Structure ◽  
Shaking Table Tests ◽  
Concrete Wall ◽  
Restoring Force ◽  
Seismically Isolated ◽  
Rubber Bearings

This paper describes the dynamic damage test of a reinforced concrete (RC) wall structure with seismic isolation sysytem. It has been expected that seismically isolated structures are damaged in sudden when the accelerations of the structures exceed a certain level by hardening of the rubber bearings. However, the response behavior and the damage mode have not been observed by experimental test yet. So, shaking table tests were carried out at “E-Defense”, equipping the world’s largest shaking table, located at Miki City, Hyogo prefecture, Japan. The specimen was composed of an upper structure of 600 ton by weight and six lead-rubber bearings (LRBs) of 505 mm in diameter which provide both stiffness and hysteretic damping. The upper structure consisted of a RC mass and four RC walls with counter weight. The RC wall structure was designed so that the damage of the RC wall occurred between the shear force at the hardening of the rubber bearings and that at their breaking. The dimensions of the RC wall were 1600 × 800 × 100 mm (B × H × t). The reinforcement ratios were 2.46% in vertical by D13 (deformed reinforcing bar, 13 mm in diameter) and 1.0% in horizontal by D10. The shaking table test was conducted consecutively by increasing the levels up to 225% of tentative design earthquake motion. Consequently, because of the increase of the structural response by the hardening of the rubber bearings, the damage of the wall structure with seismic isolation system suddenly happened. In addition, the preliminary finite element analysis simulated the test results fairly well, which were the restoring force characteristics, the crack patterns of the RC wall structure and such.

scholarly journals Experimental Approach for the Failure Mode of Small Laminated Rubber Bearings for Seismic Isolation of Nuclear Components

2021 ◽  
Vol 12 (1) ◽  
pp. 125
Author(s):  
Sang-Jin Ma ◽  
Tae-Myung Shin ◽  
Ju-Seung Ryu ◽  
Jin-Hyeong Lee ◽  
Gyeong-Hoi Koo
Keyword(s):  
Seismic Isolation ◽  
Response Spectrum ◽  
Shaking Table ◽  
Intensity Level ◽  
Shaking Table Tests ◽  
Response Characteristics ◽  
Water Jet Cutting ◽  
Total Failure ◽  
Rubber Bearings ◽  
Partial Damage

Response characteristics of small-sized laminated rubber bearings (LRBs) with partial damage and total failure were investigated. For nuclear component seismic isolation, ultimate response characteristics are mainly reviewed using a beyond design basis earthquake (BDBE). Static tests, 3D shaking table tests, and verification analyses were performed using optional LRB design prototypes. During the static test, the hysteresis curve behavior from buckling to potential damage was observed by applying excessive shear deformation. The damaged rubber surface of the laminated section inside the LRB was checked through water jet cutting. A stress review by response spectrum analysis was performed to simulate the dynamic tests and predict seismic inputs’ intensity level that triggers LRB damage. Shaking table tests were executed to determine seismic response characteristics with partial damage and to confirm the stability of the superstructure when the supporting LRBs completely fail. Shear buckling in LRBs by high levels of BDBE may be quickly initiated via partial damage or total failure by the addition of torsional or rotational behavior caused by a change in the dynamic characteristics. Furthermore, the maximum seismic displacement can be limited within the range of the design interface due to the successive slip behavior, even during total LRB failure.

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.

Shaking Table Tests With Large Test Specimens of Seismically Isolated FBR Plants: Part 3—Ultimate Behavior of Upper Structure and Rubber Bearings

2009 ◽  
Author(s):  
Shuichi Yabana ◽  
Kenji Kanazawa ◽  
Seiji Nagata ◽  
Seiji Kitamura ◽  
Takeshi Sano
Keyword(s):  
Seismic Isolation ◽  
Response Spectra ◽  
Shaking Table ◽  
Shaking Table Tests ◽  
Nuclear Facilities ◽  
Restoring Force ◽  
Isolation System ◽  
Seismically Isolated ◽  
Design Earthquake ◽  
Rubber Bearings

This paper describes results of shaking table tests to grasp ultimate behavior of seismic isolation system under extremely strong earthquake motions, including failure of rubber bearings. The results of the shaking table tests are expected to be useful for the design of seismically isolated nuclear facilities, especially fast breeder reactor (FBR) plants. In the test, lead rubber bearings, of which the diameter is 505 mm and about 1/3 scale of a prototype in planning FBR plants, are used; the test specimens are loaded by the largest three-dimensional shaking table in E-defense of National Research Institute for Earth Science and Disaster Prevention (NIED) of Japan. Failure of rubber bearings occurs with amplified tentative design earthquake motions. From the tests, the ultimate responses of the upper structure and rubber bearings are presented. In particular, the change of floor response spectra and restoring force characteristics of rubber bearings according to increase of input motions is discussed. Furthermore, mechanism of the failure of rubber bearings is investigated from the observation of failure surfaces and cut sections, static loading tests, and material tests of rubber bearings. Finally, the function of seismic isolation system after the failure of a part of rubber bearings is confirmed under the tentative design earthquake.

Original and Innovative Structural Concepts for Design, Non-Linear Analysis, and Construction of Multi-Story Base Isolated Buildings

2019 ◽  
pp. 946-986
Author(s):  
Mikayel G. Melkumyan
Keyword(s):  
Seismic Isolation ◽  
Linear Analysis ◽  
Seismic Code ◽  
The World ◽  
Fixed Base ◽  
Per Capita ◽  
Isolation Systems ◽  
Rubber Bearings ◽  
The Given ◽  
Structural Solutions

Seismic isolation of structures is becoming a more common method of providing protection from earthquake damage. Starting from 1994, 53 buildings and structures have been designed by the author of this chapter with application of base or roof isolation systems. Of these designed buildings, the total number of already constructed and retrofitted buildings has reached 45. The number of seismically isolated buildings per capita in Armenia is one of the highest in the world. Together with that seismic isolation laminated rubber-steel bearings (SILRSBs) different by their shape and dimensions, as well as by damping (low, medium and high) were designed and about 5000 SILRSBs were manufactured in the country, tested locally and applied in construction. since 2003 seismic isolation technologies were designed and then extensively applied in construction of multi-story buildings. these are: base isolated residential complexes, business centers, hotels, schools, and hospital buildings. Original and innovative structural concepts, including the new approach on installation of seismic isolation rubber bearings by clusters, were developed and designed for construction of these base isolated buildings and they are described in the given chapter. The advantages of this approach are listed and illustrated by the examples. It is mentioned that suggested new structural solutions in seismic isolation are bringing to significant savings in construction cost. The earthquake response comparative analyses were carried out for some of the considered buildings in two versions (i.e., when the buildings are base isolated and when they are fixed base). Several histories were used in the analyses and for both cases the buildings were analyzed also according to the requirements of the Armenian Seismic Code. Comparison of the obtained results indicates the high effectiveness of the proposed structural concepts of isolation systems and the need for further improvement of the Seismic Code provisions regarding the values of the reduction factors. A separate section in the chapter dedicated to the design of high damping laminated rubber-steel bearings and to results of their tests.

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.

Original and Innovative Structural Concepts for Design, Non-Linear Analysis, and Construction of Multi-Story Base Isolated Buildings

2017 ◽  
pp. 197-238
Author(s):  
Mikayel G. Melkumyan
Keyword(s):  
Seismic Isolation ◽  
Linear Analysis ◽  
Seismic Code ◽  
The World ◽  
Fixed Base ◽  
Per Capita ◽  
Isolation Systems ◽  
Rubber Bearings ◽  
The Given ◽  
Structural Solutions

Seismic isolation of structures is becoming a more common method of providing protection from earthquake damage. Starting from 1994, 53 buildings and structures have been designed by the author of this chapter with application of base or roof isolation systems. Of these designed buildings, the total number of already constructed and retrofitted buildings has reached 45. The number of seismically isolated buildings per capita in Armenia is one of the highest in the world. Together with that seismic isolation laminated rubber-steel bearings (SILRSBs) different by their shape and dimensions, as well as by damping (low, medium and high) were designed and about 5000 SILRSBs were manufactured in the country, tested locally and applied in construction. since 2003 seismic isolation technologies were designed and then extensively applied in construction of multi-story buildings. these are: base isolated residential complexes, business centers, hotels, schools, and hospital buildings. Original and innovative structural concepts, including the new approach on installation of seismic isolation rubber bearings by clusters, were developed and designed for construction of these base isolated buildings and they are described in the given chapter. The advantages of this approach are listed and illustrated by the examples. It is mentioned that suggested new structural solutions in seismic isolation are bringing to significant savings in construction cost. The earthquake response comparative analyses were carried out for some of the considered buildings in two versions (i.e., when the buildings are base isolated and when they are fixed base). Several histories were used in the analyses and for both cases the buildings were analyzed also according to the requirements of the Armenian Seismic Code. Comparison of the obtained results indicates the high effectiveness of the proposed structural concepts of isolation systems and the need for further improvement of the Seismic Code provisions regarding the values of the reduction factors. A separate section in the chapter dedicated to the design of high damping laminated rubber-steel bearings and to results of their tests.

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