The Research of Input Ground Motion on Seismic Fragility Analysis of Bridges

2012 ◽  
Vol 490-495 ◽  
pp. 1826-1830
Author(s):  
Yun Zhang ◽  
Pin Tan ◽  
Xiao Rong Zhou
Keyword(s):  
Ground Motion ◽  
Seismic Wave ◽  
Seismic Waves ◽  
Response Spectrum ◽  
Amplitude Spectrum ◽  
Fragility Analysis ◽  
Seismic Fragility ◽  
Design Response Spectrum ◽  
Methods Of Synthesis ◽  
Fourier Amplitude Spectrum

Analyzed the importance of selecting reasonably ground motion input in seismic fragility analysis of the bridge. Based on the common methods of synthesis artificial seismic wave which used trigonometric series and according to the characters of Fourier series, extracted phase spectrum from practical seismic waves ,through modulating the Fourier amplitude spectrum, obtained the artificial seismic wave which fitted compatible with the design response spectrum. Similar to nature small earthquake records, it has the character of non-stationary on time-domain and frequency-domain. Synthesize a series of artificial seismic waves in this method, can improve the accuracy and pertinence of the bridge seismic fragility.

scholarly journals Basin Resonance and Seismic Hazard for Jakarta, Indonesia

2018 ◽  
Author(s):  
Athanasius Cipta ◽  
Phil Cummins ◽  
Masyhur Irsyam ◽  
Sri Hidayati
Keyword(s):  
Ground Motion ◽  
Seismic Waves ◽  
Response Spectrum ◽  
Capital City ◽  
Earthquake Ground Motion ◽  
Computational Domain ◽  
Near Surface ◽  
Earthquake Scenario ◽  
Design Response Spectrum ◽  
Intraslab Earthquake

We use earthquake ground motion modelling via Ground Motion Prediction Equations (GMPEs) and numerical simulation of seismic waves to consider the effects of site amplification and basin resonance in Jakarta, the capital city of Indonesia. While spectral accelerations at short periods are sensitive to near-surface conditions (i.e., Vs30), our results suggest that, for basins as deep as Jakarta’s, available GMPEs cannot be relied upon to accurately estimate the effect of basin depth on ground motions at long periods (>1 s). Amplitudes at such long periods are influenced by entrapment of seismic waves in the basin, resulting in longer duration of strong ground motion, and interference between incoming and reflected waves as well as focusing at basin edges may amplify seismic waves. In order to simulate such phenomena in detail, a basin model derived from a previous study is used as a computational domain for deterministic earthquake scenario modeling in a 2-dimensional cross-section. A Mw 9.0 megathrust, a Mw 6.5 crustal thrust and a Mw 7.0 instraslab earthquake are chosen as scenario events that pose credible threats to Jakarta, and the interactions with the basin of seismic waves generated by these events were simulated. The highest PGV amplifications are recorded at sites near the middle of the basin and near its southern edge, with maximum amplifications of PGV in the horizontal component of 200% for the crustal, 600% for the megathrust and 335% for the deep intraslab earthquake scenario, respectively. We find that the levels of ground motion response spectral acceleration fall below those of the 2012 Indonesian building Codes's design response spectrum for short periods (< 1 s), but closely approach or may even exceed these levels for longer periods.

FAS-Compatible Synthetic Signals for Equivalent-Linear Site Response Analyses

2018 ◽  
Vol 34 (1) ◽  
pp. 377-396 ◽  
Author(s):  
Margarita Chi-Miranda ◽  
Luis A. Montejo
Keyword(s):  
Site Response ◽  
Response Spectrum ◽  
Amplitude Spectrum ◽  
Extreme Value Statistics ◽  
Current Time ◽  
Equivalent Linear ◽  
Inelastic Demand ◽  
Design Response Spectrum ◽  
The Time Domain ◽  
Fourier Amplitude Spectrum

An alternative approach to generate the seismic input for equivalent-linear (EQL) site response analyses is proposed. The proposed approach encompasses the strengths from current time histories (THs) and random vibration theory (RVT) methods. It consists of the generation of synthetic signals in the time domain (analogous to the TH method) that are constructed to have a Fourier amplitude spectrum (FAS) compatible with the design response spectrum (analogous to the RVT method). Through this approach, the use of extreme value statistics (used in RVT and known to overestimate amplification functions) is avoided. Moreover, the need to develop an appropriate suite of realistic acceleration series, which is the most challenging and time-consuming part of the TH-based approach, is also circumvented. The methodology is evaluated through a comprehensive analysis that includes different site conditions, input spectral shapes, duration scenarios, levels of inelastic demand, and number of synthetic signals used.

Study on Seismic Fragility of Air Heat Exchanger for CEFR

2013 ◽  
Author(s):  
Zhiwei Fu ◽  
Donghui Zhang ◽  
Tianyi Zhang ◽  
Chunming Zhang ◽  
Jiaxu Zuo ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
Response Spectrum ◽  
Heat Removal ◽  
Fragility Analysis ◽  
Seismic Fragility ◽  
Seismic Capacity ◽  
Response Factors ◽  
Element Analysis ◽  
Median Response ◽  
Heat Removal System

Seismic Fragility Analysis is studied, then the basic fragility analysis variables and their quantification methods which are used to analyze and calculate the seismic fragility of the air heat exchanger of passive accident heat removal system for China Experiment Fast Rector (CEFR) are introduced. Next, the median response spectrum in NUREG0098 is used to calculate median response factors of both structure and equipment, and finite element analysis is used to determine the capacity factor for the equipment. Finally, the results show that the median seismic capacity of the air heat exchanger is 3.53g which has the inherent randomness about the median and the uncertainty in the median value, respectively, 0.36 and 0.47, and the high confidence low probabilistic failure (HCLPF) capacity is 0.9g, so the air heat exchanger has a better seismic capacity.

Effects of Site Classification on Platform Value of Response Spectrum

2011 ◽  
Vol 378-379 ◽  
pp. 306-309
Author(s):  
Ping Li ◽  
Jing Shan Bo ◽  
Xiao Yun Guo ◽  
You Wei Sun ◽  
Yu Dong Zhang
Keyword(s):  
Ground Motion ◽  
Seismic Design ◽  
Wave Motion ◽  
Response Spectrum ◽  
Equivalent Linearization ◽  
Earthquake Response ◽  
Response Analysis ◽  
Site Classification ◽  
Earthquake Motion ◽  
Design Response Spectrum

Regarding the design response spectrum in the code for seismic design of buildings as target spectra，the 28 acceleration histories are formed artificially．They are used as the inputs ground motion in earthquake response analysis．Four site classifications profiles were selected or constructed from practical site profiles．With the use of 1-D equivalent linearization wave motion method that is wildly used at present in site seismic response analysis, the platform values of surface response spectrum for different profiles under different ground motion inputs were calculated．Different platform values of the response spectrum and relational expression which is seven input earthquake motion intensity and site classifications have been given by statistical analysis.

Study on Far-Field Ground Motion Characteristics

2013 ◽  
Vol 438-439 ◽  
pp. 1471-1473
Author(s):  
Gong Lian Chen ◽  
Wen Zheng Lu ◽  
Lei Wang ◽  
Qi Wu
Keyword(s):  
Ground Motion ◽  
Seismic Design ◽  
Seismic Waves ◽  
Response Spectrum ◽  
Engineering Application ◽  
Seismic Attenuation ◽  
Far Field ◽  
Propagation Process ◽  
Ground Acceleration ◽  
Motion Characteristics

In order to study the far-field ground motion characteristics and the attenuation of seismic waves, the peak ground acceleration (velocity, displacement), time of duration and response spectrum of the seismic waves were analyzed in this paper. Through the investigation of earthquake wave propagation process, the seismic attenuation low was analyzed. This study can provide technical support for the seismic design of long period structures and related engineering application.

A Study of Elasto-Plastic Response of Single Degree of Freedom System Using Artificial Ground Motions With Given Time-Frequency Characteristics

2010 ◽  
Author(s):  
Ichiro Ichihashi ◽  
Akira Sone ◽  
Arata Masuda ◽  
Daisuke Iba
Keyword(s):  
Ground Motion ◽  
Response Spectrum ◽  
Ground Motions ◽  
Frequency Characteristics ◽  
Earthquake Ground Motion ◽  
Time Frequency ◽  
Displacement Response ◽  
Earthquake Ground Motions ◽  
Design Response Spectrum ◽  
The Given

In this paper, a number of artificial earthquake ground motions compatible with time-frequency characteristics of recorded actual earthquake ground motion as well as the given target response spectrum are generated using wavelet transform. The maximum non-dimensional displacement of elasto-plastic structures excited these artificial earthquake ground motions are calculated numerically. Displacement response, velocity response and cumulative input energy are shown in the case of the ground motion which cause larger displacement response. Under the given design response spectrum, a selection manner of generated artificial earthquake ground motion which causes lager maximum displacement response of elasto-plastic structure are suggested.

scholarly journals A Centrifuge Model Test of the Ground Motion Response in a Moderately Stiff Soil

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Jing-Yan Lan ◽  
Ting Wang ◽  
Diwakar Khatri Chhetri ◽  
Mohammad Wasif Naqvi ◽  
Liang-Bo Hu
Keyword(s):  
Ground Motion ◽  
Seismic Waves ◽  
Response Spectrum ◽  
Time History ◽  
Centrifuge Model Test ◽  
Peak Time ◽  
Motion Response ◽  
Centrifuge Model ◽  
Amplification Effect ◽  
Stiff Soil

The ground motion response in a moderately stiff soil in seismic events has been traditionally studied based on the actual field records which, however, have yet to offer consistent results regarding the amplification effect of the ground motion. In the present study, a centrifuge model of the moderately stiff soil field is designed to study the amplification effect of the ground motion in response to seismic loads. Four El Centro waves of different strengths are used as the input wave at the base under a gravitational field of 75 g. Ground motion data at different depths are collected via a number of sensors to study the acceleration peak, time history, and response spectrum of the ground motion. The measured amplitude and energy of seismic waves are found to gradually increase from the bottom to the surface during the propagation of seismic waves, and the peak acceleration at the surface is significantly magnified. The response spectrum analysis shows that the acceleration response spectrum gradually moves to the high-frequency direction from the base to the surface and the value of the response spectrum decreases with the increase of the depth in the present study.

scholarly journals SEISMIC FRAGILITY ASSESSMENT AND RETROFIT OF A GOVERNMENT HOSPITAL BUILDING IN CHITTAGONG, BANGLADESH

2018 ◽  
Vol 30 (1) ◽  
Author(s):  
Md. AbulHasan ◽  
Md. Abdur Rahman Bhuiyan
Keyword(s):  
Ground Motion ◽  
Return Period ◽  
Seismic Vulnerability ◽  
Fragility Curves ◽  
Response Spectrum ◽  
Seismic Fragility ◽  
Earthquake Ground Motion ◽  
Type I ◽  
Type Ii ◽  
Ground Motion Records

Chittagong Medical College Hospital (CMCH) is one of the most important government hospitals in Bangladesh. It is located in the heart of Chittagong city, the only port city of Bangladesh. Bangladesh National Building Code (BNBC) is the only official document, which has been used since 1993 as guidelines for seismic design of buildings. As per the guidelines of BNBC, the CMCH building was designed for an earthquake ground motion having a return period of 200 years. However, the revised version of BNBC has suggested that the building structures shall be designed for an earthquake ground motion having a return period of 2475 years. It is mentioned that a single seismic performance objective, the life safety, of the building is considered in both versions of BNBC. Considering the significant importance of CMCH building in providing the emergency facilities during and after the earthquake, it is indispensable to evaluate its seismic vulnerability for the two types of earthquake ground motion records having return period of 200 (Type-I) and 2475 (Type-II) years. In this regard, this paper deals with the seismic vulnerability assessment of the existing ancillary building (AB) of CMCH. The seismic vulnerability of building is usually expressed in the form of fragility curves, which display the conditional probability that the structural demand (structural response) caused by various levels of ground shaking exceeds the structural capacity defined by a damage state. The analytical method based on elastic response spectrum analyses results is used in evaluating the seismic fragility curves of the building. To the end, 3-D finite element model of the building subjected to 18 ground motion records having PGA of 0.325g to 0.785g has been used in theresponse spectrum analysis in order to evaluate its inter-story-drift ratio (IDR), an engineeringdemand parameter (EDP) for developing fragility curves. The analytical results have shown thatstructural deficiencies exist in the existing ancillary building (AB) for the Type-II earthquakeground motion record, which requires the building to be retrofitted to ensure that the existingancillary building (AB) becomes functional during and after the Type-II earthquake groundmotion record.

scholarly journals Dynamic Damage Mechanism and Seismic Fragility Analysis of an Aqueduct Structure

2021 ◽  
Vol 11 (24) ◽  
pp. 11709
Author(s):  
Xinyong Xu ◽  
Xuhui Liu ◽  
Li Jiang ◽  
Mohd Yawar Ali Khan
Keyword(s):  
Ground Motion ◽  
Structural Damage ◽  
Large Scale ◽  
Seismic Analysis ◽  
Fragility Curves ◽  
Limit State ◽  
Fragility Analysis ◽  
Seismic Fragility ◽  
Exceedance Probability ◽  
Computation Efficiency

The Concrete Damaged Plasticity (CDP) constitutive is introduced to study the dynamic failure mechanism and the law of damage development to the aqueduct structure during the seismic duration using a large-scale aqueduct structure from the South-to-North Water Division Project (SNWDP) as a research object. Incremental dynamic analysis (IDA) and multiple stripe analysis (MSA) seismic fragility methods are introduced. The spectral acceleration is used as the scale of ground motion record intensity measure (IM), and the aqueduct pier top offset ratio quantifies the limit of structural damage measure (DM). The aqueduct structure’s seismic fragility evaluation curves are constructed with indicators of different seismic intensity measures to depict the damage characteristics of aqueduct structures under different seismic intensities through probability. The results show that penetrating damage is most likely to occur on both sides of the pier cap and around the pier shaft in the event of a rare earthquake, followed by the top of the aqueduct body, which requires the greatest care during an earthquake. The results of two fragility analysis methodologies reveal that the fragility curves are very similar. The aqueduct structure’s first limit state level (LS1) is quite steep and near the vertical line, indicating that maintaining the excellent condition without damage in the seismic analysis will be challenging. Except for individual results, the overall fragility results are in good agreement, and the curve change rule is the same. The exceedance probability in the case of any ground motion record IM may be estimated using only two factors when using the MSA approach, and the computation efficiency is higher. The study of seismic fragility analysis methods in this paper can provide a reference for the seismic safety evaluation of aqueducts and similar structures.

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