Derivation of site-specific UHS based on simulated ground motions and its parametric effects on building fragility

Azari Sisi, Aida
Estimation of seismic demands is essential for the purpose of structural seismic design and analyses. It is significant to obtain reliable ground motion amplitudes to estimate seismic damage on structures in a realistic manner. The ground motion simulation methodologies provide a physical approach to estimate seismic demands in the regions with sparse recording data and scarce networks. This dissertation consists of two main parts: In the first part, site-specific uniform hazard spectrum (UHS) of Erzincan region in Eastern Turkey is derived based on a stochastically-generated earthquake catalog and simulated ground motions. During the generation of the catalog, Monte Carlo simulation methodology is employed to determine spatial and temporal distribution of events. The magnitude of each event is obtained through Gutenberg-Richter recurrence relationship. Stochastic point-source and finite-fault simulation methodologies are used to calculate ground motion amplitudes. The effects of near-field forward directivity and alternative site amplification functions are studied on the proposed UHS. In the second part, the effect of proposed seismic hazard is studied on structural response and fragility. The selected ground motions from the first part are applied for nonlinear time history analyses of equivalent single degree freedom systems (ESDOF). ESDOF systems are developed such that they represent typical low-rise and mid-rise residential buildings in Erzincan. Fragility curves of building groups are then calculated based on demand predictive models. The effects of site conditions, near-field forward directivity, alternative site amplification functions and structural variability are studied on fragility functions. This study is an alternative approach to estimate seismic hazard for the regions with sparse data in which ground motion prediction equations (GMPE) may not be adequate. The proposed approach produces a regional UHS based on physical properties and complex seismicity parameters. The derived UHS mostly yield lower ground motion amplitudes than classical probabilistic seismic hazard analysis (PSHA) due to large aleatory variability inherent in PSHA. The effects of near-field forward directivity and detailed local site conditions are investigated on seismic hazard and building fragility in a practical manner. Additionally, this study provides a complete simulated ground motion database based on regional characteristics which are applied to perform sensitivity analyses of fragility functions to seismicity parameters.


Investigation of seismic isolation efficiency for building structures
Özdemir, Seda; Yakut, Ahmet; Ay, Bekir Özer; Department of Earthquake Studies (2016)
The main goal of this study is to assess the efficacy of seismic isolation for building type of structures with different structural systems, namely, dual systems and moment frame systems having also different number of floors. Specific to this study, the main parameters employed for efficacy assessment will be the interstorey drift ratio and floor acceleration since both structural and non-structural damage to be occured in a system are directly related to these two parameters. To assess the variations in inter...
Influence of seismic source and ground motion modeling on the probabilistic seismic hazard assessment of the city of Van after the 23 october 2011 mw7.2 earthquake
Şenyurt, Mehtap; Akkar, Sinan; Yılmaz, Mustafa Tolga; Department of Civil Engineering (2013)
Reliable assessment of seismic hazard is the most important step for seismic design and performance assessment of structural systems. However, the inherent uncertainty in earthquakes as well as modeling of ground motion may affect the hazard computed for a particular region. This study investigates the influence of seismic source and ground motion modeling on probabilistic seismic hazard assessment (PSHA). The study considers the seismicity around the city of Van to achieve its objective as this city was hi...
Probabilistic seismic hazard assessment for east anatolian fault zone using planar source models
Menekşe, Akın; Gülerce, Zeynep; Department of Civil Engineering (2015)
The objective of this study is to perform probabilistic seismic hazard assessment (PSHA) using planar seismic source characterization models for East Anatolian Fault Zone (EAFZ) and to update the design ground motions to be used in the region. Development of planar seismic source models requires the definition of source geometry in terms of fault length, fault width, fault plane angles and segmentation points for each segment and associating the observed seismicity with defined fault systems. This complicat...
Probabilistic methods for estimating the seismic deformations of underground structures
Soyman, Kadir Buğra; Gülerce, Zeynep; Department of Civil Engineering (2018)
In seismic design of underground structures, simplified semi-deterministic methods based on the stiffness of the soil and the underground structure are used to estimate the seismic deformations. Generally, peak ground acceleration (PGA) value for different hazard levels are provided by the probabilistic seismic hazard assessment (PSHA) analysis, but a single (and deterministic) PGA value is employed in deformation calculations. The objective of this study is to propose a fully probabilistic framework for es...
Ground motion prediction equations based on simulated ground motions
Gür, Kader; Askan Gündoğan, Ayşegül; Kale, Özkan; Department of Earthquake Studies (2018)
Ground Motion Prediction Equations (GMPEs) are one of the key elements in seismic hazard assessment to estimate ground motion intensity measures by basically taking into account source, path and site effects. Most of the existing predictive models are derived from databases compiled from real (or observed) ground motion data. However, in data-poor regions, a novel practice to develop new GMPEs is to use simulated or hybrid ground motion datasets for performing reliable seismic hazard analysis. Simulations o...
Citation Formats
A. Azari Sisi, “Derivation of site-specific UHS based on simulated ground motions and its parametric effects on building fragility,” Ph.D. - Doctoral Program, Middle East Technical University, 2016.