scholarly journals Safety Evaluation of High Concrete-Faced Rockfill Dam Based on Site-Related Response Spectrum Using Scenario Earthquake

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Kai-bin Zhu ◽  
Hong-jun Li ◽  
Xiao-gang Wang ◽  
Xiao-sheng Liu ◽  
Jian-ming Zhao
Keyword(s):  
Seismic Design ◽  
Response Spectrum ◽  
Permanent Deformation ◽  
Safety Evaluation ◽  
Economic Cost ◽  
Response Spectra ◽  
Earthquake Ground Motion ◽  
Uniform Hazard Spectra ◽  
Scenario Earthquake ◽  
Rockfill Dam

To clarify how to arrive at earthquake ground motion parameters for use in evaluating the high rockfill dams during seismic loading conditions, as well as to evaluate reasonably the seismic response of dams subjected to strong earthquake, the differences of design response spectra determined by scenario earthquake and uniform hazard spectra theory are investigated in detail. Coupled with the safety evaluation of the Houziyan concrete-faced rockfill dam (CFRD) with a height of 200 m located in meizoseismal regions, comprehensive comparisons of key safety evaluation indices are performed using input motions determined from the abovementioned two design response spectra. The key safety evaluation indices include dynamic response acceleration, permanent deformation, safety of the impervious body, safety factor, and sliding displacement of the potential failure sliding body. Additionally, the ultimate seismic capability of the high CFRD is discussed based on the two response spectra. More considerable results can be achieved and offered to the engineers for the seismic design. It is obvious that the uniform hazard spectra, which are used to adopt in the safety evaluation of high CFRD, typically result in conservative evaluations and unnecessary economic cost for seismic design and reinforcements.

Study on Piping Response Under Multiple Excitation: Part 2 — Validation for Multiple Excitation Analysis of Piping

2013 ◽  
Author(s):  
Satoru Kai ◽  
Tomoyoshi Watakabe ◽  
Naoaki Kaneko ◽  
Kunihiro Tochiki ◽  
Makoto Moriizumi ◽  
...  
Keyword(s):  
Seismic Response ◽  
Seismic Design ◽  
Nuclear Power ◽  
Response Spectrum ◽  
Time History ◽  
Response Spectra ◽  
Shaking Table ◽  
Response Analysis ◽  
Multiple Time ◽  
Floor Response Spectra

The piping in a nuclear power plant is laid across multiple floors of a single building or two buildings, which are supported at many points. As the piping is excited by multiple-inputs from the supporting points during an earthquake, seismic response analysis by multiple excitations is needed to obtain the exact seismic response of the piping. However, few experiments involving such multiple excitation have been performed to verify the validity of multiple excitation analysis. Therefore, analysis of the seismic design of piping in Japan is performed by the enveloped Floor Response Spectrum (FRS), which covers all floor response spectra at all supporting points. The piping response estimated by enveloped FRS is conservative in most cases compared with the actual seismic response by multiple excitations. To perform rational seismic design and evaluation, it is important to investigate the seismic response by multiple excitations and to verify the validity of the analytical method by multiple excitation test. This paper reports the validation results of the multiple-excitation analysis of piping compared with the results of the multiple excitations shaking test using triple uni-axial shaking table and a 3-dimensional piping model (89.1mm diameter and 5.5mm thickness). Three directional moments from the analysis and the shaking test were compared on the validation. As the result, it is confirmed that the analysis by multiple time history excitation corresponds with the test result.

Smooth Acceleration Spectra for Pulse-Like Ground Motions

2020 ◽  
Vol 110 (6) ◽  
pp. 2755-2765
Author(s):  
Cuihua Li ◽  
Guofeng Xue ◽  
Zhanxuan Zuo
Keyword(s):  
Seismic Design ◽  
Amplification Factor ◽  
Response Spectrum ◽  
Ground Motions ◽  
Response Spectra ◽  
Acceleration Response ◽  
Constant Acceleration ◽  
Step Procedure ◽  
Acceleration Response Spectrum ◽  
Smooth Acceleration

ABSTRACT Idealization of acceleration response spectra is the basis for construction of target spectra for seismic design and assessment of structures. The adequacy of current methods to reasonably idealize (or smooth) the acceleration spectra of pulse-like and nonpulse-like ground motions is examined in this study. The influence of separated pulses on different regions of acceleration response spectrum is first investigated using wavelet transform. One representative method is selected as the benchmark to examine the effectiveness of the Newmark–Hall-based methods to smooth the acceleration spectra of pulse-like and nonpulse-like ground motions. Presented are some important insights into why the plateau (or amplification factor) associated with the constant-acceleration branch may be underestimated and the ending cutoff period Tg be overestimated by Newmark–Hall-based methods. This study highlights the intrinsic characteristics and the importance of the constant-acceleration branch, based on which a two-step procedure is proposed to idealize the acceleration spectra. The results show that the proposed methodology can accurately identify the constant-acceleration branch regardless of the influence of pulses on the descending branch of acceleration spectra.

Period Dependence of Response Spectrum Damping Modification Factors due to Source- and Site-Specific Effects

2015 ◽  
Vol 31 (2) ◽  
pp. 745-759 ◽  
Author(s):  
Brendon A. Bradley
Keyword(s):  
Seismic Design ◽  
Response Spectrum ◽  
Response Spectra ◽  
Empirical Formulas ◽  
Site Specific ◽  
Soil Response ◽  
Specific Effects ◽  
Spectral Peaks ◽  
Displacement Based ◽  
Displacement Based Seismic Design

Response spectrum damping modification factors are key components of displacement-based seismic design methods. This paper examines the period dependence of damping modification factors as a result of near-source forward directivity, basin-induced surface waves, and surficial soil response by using recorded ground motions from the Canterbury, New Zealand, earthquakes as examples. It is illustrated that spectral peaks in the 5% damped response spectra have systematically different damping modification factors than those suggested by conventional empirical formulas; this is also supported by arguments based on forced vibration theory. Because source- and site-specific effects are increasingly being considered in the development of region- or site-specific design response spectra, this work illustrates the critical need to adequately consider adjustments to damping modification factors to ensure that displacement-based seismic design procedures remain consistent.

Bi-Directional Pseudo-Acceleration Response Spectra

2016 ◽  
Vol 10 (04) ◽  
pp. 1650007
Author(s):  
Anat Ruangrassamee ◽  
Chitti Palasri ◽  
Panitan Lukkunaprasit
Keyword(s):  
Seismic Design ◽  
Response Spectrum ◽  
Ground Motions ◽  
Strong Motion ◽  
Response Spectra ◽  
Acceleration Response ◽  
Acceleration Response Spectra ◽  
Acceleration Response Spectrum ◽  
Two Degree Of Freedom ◽  
Ratio Response

In seismic design, excitations are usually considered separately in two perpendicular directions of structures. In fact, the two components of ground motions occur simultaneously. This paper clarifies the effects of bi-directional excitations on structures and proposes the response spectra called “bi-directional pseudo-acceleration response spectra”. A simplified analytical model of a two-degree-of-freedom system was employed. The effect of directivity of ground motions was taken into account by applying strong motion records in all directions. The analytical results were presented in the form of the acceleration ratio response spectrum defined as the bi-directional pseudo-acceleration response spectrum normalized by a pseudo-acceleration response spectrum.

scholarly journals Towards Seismic Design of Nonstructural Elements: Italian Code-Compliant Acceleration Floor Response Spectra

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Beatrice Chichino ◽  
Simone Peloso ◽  
Davide Bolognini ◽  
Claudio Moroni ◽  
Daniele Perrone ◽  
...  
Keyword(s):  
Seismic Design ◽  
Earthquake Engineering ◽  
Response Spectrum ◽  
Response Spectra ◽  
Building Structure ◽  
Reinforced Concrete Frame ◽  
Dynamic Simulations ◽  
Concrete Frame ◽  
Floor Response Spectra ◽  
Frame Building

Seismic risk reduction of a building system, meant as primary building structure and nonstructural elements (NSEs) as a whole, must rely upon an adequate design of each of these two items. As far as NSEs are concerned, adequate seismic design means understanding of some basic principles and concepts that involve different actors, such as designers, manufacturers, installers, and directors of works. The current Italian Building Code, referred to as NTC18 hereinafter, defines each set of tasks and responsibilities in a sufficiently detailed manner, rendering now evident that achieving the desired performance level stems from a jointed contribution of all actors involved. Bearing in mind that seismic design is nothing else than proportioning properly seismic demand, in terms of acceleration and/or displacement, and the corresponding capacity, this paper gives a synthetic and informative overview on how to evaluate these two parameters. To shed some light on this, the concept of acceleration floor response spectrum (AFRS) is firstly brought in, along with basics of building structure-NSEs interaction, and is then deepened by means of calculation methods. Both the most rigorous method based on nonlinear dynamic simulations and the simplified analytical formulations provided by the NTC18 are briefly discussed and reviewed, trying to make them clearer even to readers with no structural/earthquake engineering background because, as a matter of fact, NSEs are often selected by architects and/or mechanical or electrical engineers. Lastly, a simple case study, representative of a European code-compliant five-storey masonry-infilled reinforced concrete frame building, is presented to examine differences between numerical and analytical AFRS and to quantify accuracy of different NTC18 procedures.

Study on Piping Response Under Multiple Excitation: Part 1 — Triple Shaking Table Test of Piping Having Three-Supporting Points

2013 ◽  
Author(s):  
Tomoyoshi Watakabe ◽  
Naoaki Kaneko ◽  
Shigekazu Aida ◽  
Akihito Otani ◽  
Makoto Moriizumi ◽  
...  
Keyword(s):  
Seismic Response ◽  
Seismic Design ◽  
Nuclear Power ◽  
Shaking Table Test ◽  
Response Spectrum ◽  
Response Spectra ◽  
Shaking Table ◽  
Response Analysis ◽  
3 Dimensional ◽  
Floor Response Spectra

The piping in a nuclear power plant is laid across multiple floors of a single building or two buildings, which are supported at many points. As the piping is excited by multiple inputs from the supporting points during an earthquake, seismic response analysis by multiple excitations is needed to obtain the exact seismic response of the piping. However, few experiments involving such multiple excitations have been performed to verify the validity of multiple excitation analysis. Therefore, analysis of the seismic design of piping in Japan is performed by the enveloped Floor Response Spectrum (FRS), which covers all floor response spectra at all supporting points. The piping response estimated by enveloped FRS is conservative in most cases compared with the actual seismic response by multiple excitations. To perform rational seismic design and evaluation, it is important to investigate the seismic response by multiple excitations and verify the validity of the analysis method by multiple-excitation test. This paper reports on the result of the shaking test using triple uni-axial shaking tables and a 3-dimensional piping model (89.1mm in diameter and 5.5mm thickness). The piping model was fixed to three shaking tables, meaning three. Different inputs were possible. By the shaking test, dynamic behavior under multiple excitations was confirmed, and data to verify multiple-excitation analysis was obtained.

scholarly journals Study on Response Spectrum of Seismic Design of Ultra High Voltage Converter Valves in Bedrock Site

2021 ◽  
Vol 2083 (2) ◽  
pp. 022101
Author(s):  
Yongfeng Cheng ◽  
Sen Lin ◽  
Hongbing You ◽  
Zhicheng Lu ◽  
Ersong Chen
Keyword(s):  
Seismic Performance ◽  
Seismic Design ◽  
High Voltage ◽  
Response Spectrum ◽  
Response Spectra ◽  
Exceedance Probability ◽  
Period Range ◽  
Long Period ◽  
Design Response Spectrum ◽  
Ultra High Voltage

Abstract It is difficult to evaluate seismic performance of ultra-high voltage (UHV) converter valves reasonably because the response spectrum period used in seismic design of electrical equipment fails to cover the structural period of UHV converter valves at present. Bedrock response spectrum is the basis of seismic design response spectrum. 471 records of long period strong earthquakes in bedrock were analysed. The amplification power spectra and average spectra of all records were calculated. The seismic hazard analysis of 17 typical UHV converter stations was carried out, and the bedrock response spectra with exceedance probability of 10% and 2% in 50 years were proposed. The structural forms of the existing main response spectrum descending segments were compared and analysed. The corresponding response spectra of the long period strong earthquake records and the bedrock response spectra of the UHV converter station were fitted. The bedrock response spectrum of the UHV converter valves with the period range of 0-10s was determined, which lays a foundation for the seismic performance evaluation of the UHV converter valves.

Seismic Design and Safety Evaluation Analysis of Reinforced Slope with Geogrid in 200m High Core Rock-Fill Dams

2012 ◽  
Vol 204-208 ◽  
pp. 2539-2549
Author(s):  
Hong Jun Li ◽  
Zu Wen Yan ◽  
Yan Yi Zhang
Keyword(s):  
Seismic Design ◽  
Ant Colony Algorithm ◽  
Permanent Deformation ◽  
Evaluation Criteria ◽  
Safety Evaluation ◽  
Time History ◽  
Vertical Acceleration ◽  
Rock Fill ◽  
Sliding Method ◽  
Fill Materials

The reinforcement technique with strengthening geogrid has been widely used in modern seismic design of 200m high rock-fill dams. However, how to evaluate accurately the effects of reinforcement in seismic design and safety evaluation has become a key problem. As compared with the minimum safety factors which are conventionally employed as the evaluation criteria, the earthquake-induced deformation can better reflect the characteristics of rock-fill materials, input motion and the performance of reinforced dams for the earthquake loading. In the improved Newmark sliding method, the effects of reinforcement in enhancing the stability of slope in high rock-fill dams and restricting the permanent deformation of dams are investigated. Firstly, the limit tensile intensity and limit coordinating strain of reinforcement is determined based on the stress-strain relationship of reinforcement-composite and rock-fill materials. Secondly, the location of critical failure face is determined via a combination of ant colony algorithm and Holland method. The yielding acceleration of potential sliding bodies, which considers the limited stress of reinforcement layers and time-history vertical acceleration, is obtained. Finally, the transient movements are accumulated for all the overloadings. It is guaranteed that the reinforcement can reduce the permanent deformation up to 80% and improve the seismic design and safety evaluation of high rock-fill dams subjected to strong ground motion effectively.

scholarly journals Construction of a Site- and Period-Specific Seismic Hazard Map for the Korean Peninsula

2020 ◽  
Vol 20 (2) ◽  
pp. 207-220
Author(s):  
Hyun Woo Jee ◽  
Sang Whan Han
Keyword(s):  
Seismic Hazard ◽  
Seismic Design ◽  
Korean Peninsula ◽  
Response Spectrum ◽  
Response Spectra ◽  
Earthquake Damage ◽  
Economic Damage ◽  
Hazard Maps ◽  
Ground Acceleration ◽  
Seismic Hazard Maps

The 2016 Gyeongju and 2017 Pohang earthquakes caused casualties and economic damage in the surrounding areas. Therefore, the importance of earthquake damage prediction and seismic design in the Korean peninsula has increased. Probabilistic seismic hazard analysis (PSHA) is one of the well-known methods for predicting earthquake damage. The objective of this study is to construct Korean Peninsula seismic hazard maps of 5% damped response spectrum acceleration and peak ground acceleration, using PSHA. To consider the local effects for each site's classification, seismic hazard maps were constructed by considering the site amplification model. To conduct seismic design, uniform hazard response spectra (UHRS) were also constructed for the Korean peninsula.

Typical uniform hazard spectra for eastern North American sites at low probability levels

2007 ◽  
Vol 34 (1) ◽  
pp. 12-18 ◽  
Author(s):  
Gail M Atkinson ◽  
Medhat Elgohary
Keyword(s):  
Ground Motion ◽  
Nuclear Power ◽  
Response Spectrum ◽  
Spectral Shape ◽  
Earthquake Ground Motion ◽  
Uniform Hazard Spectra ◽  
Uniform Hazard Spectrum ◽  
Standard Spectrum ◽  
Moderate Seismicity ◽  
Standard Design

Seismic design for nuclear power facilities is generally based on a prescribed earthquake response spectrum, which defines the response of a simple oscillator of a given natural frequency to the expected motions. To develop standard designs that may be suitable in a number of possible future locations, it is useful to develop standard spectra that describe typical environments. The adequacy of the standard design for a particular location may then be judged based on comparison of the standard spectrum with a site-specific "uniform hazard spectrum" (UHS). In this paper, UHS results from selected publicly available studies are used to develop a standard spectral shape that describes moderate-seismicity sites in eastern North America, on hard-rock site conditions. Compared with a standard spectrum that has been suggested for future nuclear plants on rock sites (modified Canadian Standards Association CSA/CAN-N289.3), the spectral shape proposed herein has higher amplitudes at high frequencies and lower amplitudes at low frequencies.Key words: earthquake ground motion, response spectrum, nuclear power plant, spectral shape, design ground motion.

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