Search for: spectral-acceleration
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    Nonlinear analysis of aboveground anchored steel tanks using endurance time method

    , Article Asian Journal of Civil Engineering ; Volume 12, Issue 6 , 2011 , Pages 731-750 ; 15630854 (ISSN) Alembagheri, M ; Estekanchi, H. E ; Sharif University of Technology
    Aboveground steel tanks are widely utilized in residential and industrial areas, and assurance of their seismic safety is a very important engineering consideration. In this paper, nonlinear response of these tanks using a new dynamic pushover procedure called Endurance Time (ET) method along with conventional nonlinear response history (RHA) is studied. The comparison between the results of RHA and ET method shows reasonable consistency. Based on the level of accuracy observed in this research, it is concluded that ET method can effectively be used in predicting seismic performance of anchored tanks. By considerably reducing the number of required response history analyses for estimating... 

    Seismic Hazard Analysis Using Reliability-Based Methods for Cumalitive Absolute Velocity and Spectral Acceleration in the Iranian Plateau Depending on National Database

    , M.Sc. Thesis Sharif University of Technology Rahimi, Hossein (Author) ; Bakhshi, Ali (Supervisor) ; Mahsuli, Mojtaba (Supervisor)
    This thesis presents a new approach to probabilistic seismic hazard analysis. Hazard in this context means the probability of exceeding a measure of earthquake intensity. The main components of the proposed approach are twofold: 1) Reliability methods compute the exceedance probabilities; 2) Multiple probabilistic models compute the earthquake intensity. These two components are presented in details. The proposed methodology is employed in a comprehensive seismic hazard analysis of Iran with an area of nearly 1.65 million square kilometers and 112 sources of seismicity. In this analysis, a grid of 2045 points is chosen to produce a high resolution hazard map. The analysis is carried out for... 

    Modeling of Epistemic Uncertainties in Seismic Hazard Analysis Based on Reliability Methods

    , M.Sc. Thesis Sharif University of Technology Askari, Mohammad (Author) ; Mahsouli, Mojtaba (Supervisor)
    The primary objective of this thesis is comprehensive treatment of epistemic uncertainties in probabilistic seismic hazard analysis based on structural reliability methods. The classical methods of probabilistic seismic hazard analysis, i.e., PSHA, traditionally consider a limited number of uncertainties. The ones that they do consider comprise the aleatory uncertainty in the magnitude, the distance, and the residuals of ground motion prediction equations and the epistemic uncertainty in the intensity measures predicted by different such equations. However, there are many sources of epistemic uncertainty that, according to past studies, have a significant impact on the upper tail of the... 

    Soil-Structure interaction effect on fragility curve of 3D models of concrete moment-resisting buildings

    , Article Shock and Vibration ; Volume 2018 , 2018 ; 10709622 (ISSN) Anvarsamarin, A ; Rahimzadeh Rofooei, F ; Nekooei, M ; Sharif University of Technology
    Hindawi Limited  2018
    This paper presents the probabilistic generation of collapse fragility curves for evaluating the performance of 3D, reinforced concrete (RC) moment-resisting building models, considering soil-structure interaction (SSI) by concentration on seismic uncertainties. It considers collapse as the loss of lateral load-resisting capacity of the building structures due to severe ground shaking and consequent large interstory drifts intensified by P-Δ effects as well as the strength and stiffness deterioration of their lateral load carrying systems. The estimation of the collapse performance of structures requires the relation between the intensity measure (IM) and the probability of collapse... 

    The exact and approximate conditional spectra in the multi-seismic-sources regions

    , Article Soil Dynamics and Earthquake Engineering ; Volume 39 , August , 2012 , Pages 61-77 ; 02677261 (ISSN) Ebrahimian, H ; Azarbakht, A ; Tabandeh, A ; Akbar Golafshani, A ; Sharif University of Technology
    Elsevier  2012
    The exact and two approximate conditional spectra are compared in this manuscript as a target spectrum for the purpose of ground motion selection. The considered site is a real offshore site located at South Pars Gas Field in the Persian Gulf region. This case study site is influenced by four major seismic area sources in which the deaggregation results confirm that many comparable seismic scenarios can be taken into account. Therefore, an alternative to the conventional approximate conditional spectrum is proposed that has a small deviation from the exact solution. In addition, the use of different conditioning status of the probabilistic seismic hazard deaggregation (i.e., occurrence... 

    Estimation of stress drop for some large shallow earthquakes using stochastic point source and finite fault modeling

    , Article Scientia Iranica ; Volume 17, Issue 3 A , JUNE , 2010 , Pages 217-235 ; 10263098 (ISSN) Moghaddam, H ; Fanaie, N ; Motazedian, D ; Sharif University of Technology
    Using stochastic point source and finite fault modeling, the stochastic stress drop is estimated for 52 large shallow earthquakes listed in the 'Pacific Earthquake Engineering Research Center (PEER) Next Generation Attenuation of Ground Motions (NGA)' database. The Pseudo Spectral Acceleration (PSA) of 541 accelerograms, recorded at National Earthquake Hazards Reduction Program (NEHRP) C-class sites from 52 earthquakes are simulated and compared with the PSA listed in the PEER NGA database. The magnitude of the analyzed earthquakes ranged from M4:4 to M7:6. The stress drop is calibrated by trial and error and based on the analysis of residuals where the residual is defined as the log of the... 

    Uniform hazard response spectra and ground motions for tabriz

    , Article Scientia Iranica ; Volume 16, Issue 3 , 2009 , Pages 238-248 ; 10263098 (ISSN) Moghaddam, H ; Fanaie, N ; Hamzehloo, H ; Sharif University of Technology
    Tabriz has experienced several large destructive historical earthquakes in the past. Due to the absence of ground motion records in this area, a simulation of future events based on a regional seismicity information and ground motion model is necessary. Based on a maximum likelihood method, earthquake magnitude is estimated for a 10% probability of exceedance within 50 years (475-year return period) and its corresponding strong ground motions have been simulated using stochastic finite fault modeling. Using different stress parameters, suites of ground motions have been simulated for a return period of £75 years and their spectral accelerations have been compared with the corresponding...