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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Development Of Site Specific Vertical Design Spectrum For Turkey

Akyuz, Emre 01 January 2013 (has links) (PDF)
Vertical design spectra may be developed in a probabilistic seismic hazard assessment (PSHA) by computing the hazard using vertical ground motion prediction equations (GMPEs), or using a vertical-to-horizontal spectral acceleration (V/H) ratio GMPEs to scale the horizontal spectrum that was developed using the results of horizontal component PSHA. The objective of this study is to provide GMPEs that are compatible with regional ground motion characteristics to perform both alternatives. GMPEs for the V/H ratio were developed recently by G&uuml / lerce and Abrahamson (2011) using NGA-W1 database. A strong motion dataset consistent with the V/H ratio model parameters is developed by including strong motion data from earthquakes occurred in Turkey with at least three recordings per earthquake. The compatibility of GA2011 V/H ratio model with the magnitude, distance, and site amplification scaling of Turkish ground motion dataset is evaluated by using inter-event and intra-event residual plots and necessary coefficients of the model is adjusted to reflect the regional characteristics. Analysis of the model performance in the recent moderate-tolarge magnitude earthquakes occurred in Turkey shows that the Turkey-Adjusted GA2011 model is a suitable candidate V/H ratio model for PSHA studies conducted in Turkey. Using the same dataset, a preliminary vertical ground motion prediction equation for Turkey consistent with the preliminary vertical model based on NGA-W1 dataset is developed. Proposed preliminary model is applicable to magnitudes 5-8.5, distances 0-200 km, and spectral periods of 0-10 seconds and offers an up-to-date alternative to the regional vertical GMPEs proposed by Kalkan and G&uuml / lkan (2004).
2

Development of Computational Tools for Characterization, Evaluation, and Modification of Strong Ground Motions within a Performance-Based Seismic Design Framework

Syed, Riaz 27 January 2004 (has links)
One of the most difficult tasks towards designing earthquake resistant structures is the determination of critical earthquakes. Conceptually, these are the ground motions that would induce the critical response in the structures being designed. The quantification of this concept, however, is not easy. Unlike the linear response of a structure, which can often be obtained by using a single spectrally modified ground acceleration history, the nonlinear response is strongly dependent on the phasing of ground motion and the detailed shape of its spectrum. This necessitates the use of a suite (bin) of ground acceleration histories having phasing and spectral shapes appropriate for the characteristics of the earthquake source, wave propagation path, and site conditions that control the design spectrum. Further, these suites of records may have to be scaled to match the design spectrum over a period range of interest, rotated into strike-normal and strike-parallel directions for near-fault effects, and modified for local site conditions before they can be input into time-domain nonlinear analysis of structures. The generation of these acceleration histories is cumbersome and daunting. This is especially so due to the sheer magnitude of the data processing involved. The purpose of this thesis is the development and documentation of PC-based computational tools (hereinafter called EQTools) to provide a rapid and consistent means towards systematic assembly of representative strong ground motions and their characterization, evaluation, and modification within a performance-based seismic design framework. The application is graphics-intensive and every effort has been made to make it as user-friendly as possible. The application seeks to provide processed data which will help the user address the problem of determination of the critical earthquakes. The various computational tools developed in EQTools facilitate the identification of severity and damage potential of more than 700 components of recorded earthquake ground motions. The application also includes computational tools to estimate the ground motion parameters for different geographical and tectonic environments, and perform one-dimensional linear/nonlinear site response analysis as a means to predict ground surface motions at sites where soft soils overlay the bedrock. While EQTools may be used for professional practice or academic research, the fundamental purpose behind the development of the software is to make available a classroom/laboratory tool that provides a visual basis for learning the principles behind the selection of ground motion histories and their scaling/modification for input into time domain nonlinear (or linear) analysis of structures. EQTools, in association with NONLIN, a Microsoft Windows based application for the dynamic analysis of single- and multi-degree-of-freedom structural systems (Charney, 2003), may be used for learning the concepts of earthquake engineering, particularly as related to structural dynamics, damping, ductility, and energy dissipation. / Master of Science

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