Mitigation of the Seismic Response of Structures with Vertical Stiffness and Strength Irregularity Using Supplemental Dampers

Earthquake observation records were observed in reactor buildings of Kashiwazaki-Kariwa Nuclear Power Plant Site during the Niigata-ken Chuetsu-oki earthquake in 2007 (NCO). Some studies on the seismic response and simulation analyses were performed to investigate dynamic characteristics of the structures. In particular, it was clarified that the vertical motions of the reactor building of Unit 6 were greater than those of adjacent reactor buildings of Unit 5 and Unit 7. This paper discusses the causes of this by earthquake observation records and simulation analyses of the reactor buildings. In general, seismic response of vertical motions is relatively well-simulated using lumped mass model with stick elements that have vertical stiffness and with the soil spring between the basemat and support ground. However, vertical motions are influenced by rocking motions with horizontal response in some cases. This paper focuses on relationships between the vertical responses and the vertical motions induced by the rocking motions with simulation analyses and observation records during both NCO earthquake and aftershock of NCO. The reasons why the vertical motions of the reactor building of Unit 6 were larger are discussed.

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Study of isolation effectiveness of nuclear reactor building with three-dimensional seismic base isolation

Engineering Computations ◽

10.1108/ec-11-2020-0637 ◽

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Xiuyun Zhu ◽

Rong Pan ◽

Jianbo Li ◽

Gao Lin

Keyword(s):

Seismic Response ◽

Nuclear Reactor ◽

Base Isolation ◽

Three Dimensional ◽

Seismic Action ◽

Peak Acceleration ◽

Content Type ◽

Vertical Stiffness ◽

Reactor Building ◽

Seismic Base Isolation

PurposeIn recent years, three-dimensional (3D) seismic base isolation system has been studied extensively. This paper aims to propose a new 3D combined isolation bearing (3D-CIB) to mitigate the seismic response in both the horizontal and vertical directions.Design/methodology/approachThe new 3D-CIB composed of laminated rubber bearing coupled with combined disk spring bearing (CDSB) was proposed. Comprehensive analysis of constitution and theoretical derivation for 3D-CIB were presented. The advantage of CDSB is that the constitution can be flexibly adjusted according to the requirements of the bearing capacity and vertical stiffness. Hence, four different combinations of CDSB were designed for the 3D-CIB and employed to isolate nuclear reactor building. A comparative study of the seismic response in terms of seismic action, acceleration floor response spectra (FRS), peak acceleration and relative displacement response was carried out.Findings3D-CIB can effectively reduce seismic action, FRS and peak acceleration response of the superstructure in both the horizontal and vertical directions. Overall, the horizontal isolation effectiveness of 3D-CIB was slightly influenced by vertical stiffness. The decrease in the vertical stiffness of the 3D-CIB can reduce the vertical FRS and shift the peak values to a lower frequency. The vertical peak acceleration decreased with a decrease in the vertical stiffness. The superstructure exhibited a rocking effect during the earthquake, and the decrease in the vertical stiffness may increase the rocking of the superstructure.Originality/valueAlthough the advantage of 3D-CIB is that the vertical stiffness can be flexibly adjusted by different constitutions, the vertical stiffness should be designed by properly accounting for the balance between the isolation effectiveness and displacement response. This study of isolation effectiveness can provide the technical basis for the application of 3D-CIB into real engineering of nuclear power plants.

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Seismic response of structures with coupled vertical stiffness-strength irregularities

Earthquake Engineering & Structural Dynamics ◽

10.1002/eqe.1121 ◽

2011 ◽

Vol 41 (1) ◽

pp. 119-138 ◽

Cited By ~ 8

Author(s):

Vinod K. Sadashiva ◽

Gregory A. MacRae ◽

Bruce L. Deam

Keyword(s):

Seismic Response ◽

Vertical Stiffness

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Seismic Response of Precast Prestressed Concrete Frames With Partially Debonded Tendons

PCI Journal ◽

10.15554/pcij.01011993.58.69 ◽

1993 ◽

Vol 38 (1) ◽

pp. 58-69 ◽

Cited By ~ 121

Author(s):

M. J. Nigel Priestley ◽

Jian Ren Tao

Keyword(s):

Seismic Response ◽

Prestressed Concrete ◽

Concrete Frames ◽

Precast Prestressed Concrete

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Seismic response of precast, posttensioned concrete jointed wall systems designed for low- to midrise buildings using the direct displacement-based approach

PCI Journal ◽

10.15554/pcij.03012015.38.56 ◽

2015 ◽

Vol 60 (2) ◽

pp. 38-56 ◽

Cited By ~ 7

Author(s):

M. Ataur Rahman ◽

Sri Sritharan

Keyword(s):

Seismic Response ◽

Posttensioned Concrete ◽

Displacement Based

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Influence of the distribution of the shear walls on the seismic response of the buildings

Pollack Periodica ◽

10.1556/606.2020.15.1.4 ◽

2020 ◽

Vol 15 (1) ◽

pp. 37-44

Author(s):

El Mehdi Echebba ◽

Hasnae Boubel ◽

Oumnia Elmrabet ◽

Mohamed Rougui

Keyword(s):

Structural Analysis ◽

Seismic Response ◽

Natural Frequency ◽

Structural Design ◽

Structural Response ◽

Shear Walls ◽

Structural Elements ◽

Analysis Software ◽

Ansys Apdl ◽

The Impact

Abstract In this paper, an evaluation was tried for the impact of structural design on structural response. Several situations are foreseen as the possibilities of changing the distribution of the structural elements (sails, columns, etc.), the width of the structure and the number of floors indicates the adapted type of bracing for a given structure by referring only to its Geometric dimensions. This was done by studying the effect of the technical design of the building on the natural frequency of the structure with the study of the influence of the distribution of the structural elements on the seismic response of the building, taking into account of the requirements of the Moroccan earthquake regulations 2000/2011 and using the ANSYS APDL and Robot Structural Analysis software.

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