Download or read book Empirical Characterization of Site Conditions on Strong Ground Motion written by Jonathan P. Stewart and published by . This book was released on 2005 with total page 197 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Semi empirical Characterization of Ground Motions Including Source Path and Nonlinear Site Effects written by Emel Seyhan and published by . This book was released on 2013 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this thesis is to improve the physical understanding of earthquake ground motion characteristics related to source, path and nonlinear site effects and our ability to model those effects with engineering models. This was achieved through four research studies consisting of: (1) calibrating broadband simulation procedures to remove previously recognized sources of bias in distance attenuation and standard deviation; (2) enhancing a site database used for assigning site parameters to ground motion recordings, particularly with regard to the level of rigor and transparency with which the database is populated; (3) leveraging a state-of-the-art ground motion database and recent simulation-based studies to develop a nonlinear site amplification model suitable for use in g̲round m̲otion p̲redictions e̲quations (GMPEs) and relatively simplified building code applications; and (4) developing GMPEs that provides mean and standard deviation of ground motion intensity measures in active crustal regions. The high-frequency component of the simulation procedure considered in this study combines deterministic Fourier amplitude spectra (dependent on source, path, and site models) with random phase. Significantly too-fast distance attenuation bias identified in prior work has been removed by increasing the quality factor (Q). We introduced random site-to-site variations to Fourier amplitudes using a log-normal standard deviation ranging from 0.45 for M 7 to zero for M8 to achieve dispersion terms that are more compatible with those from empirical models but remain lower at large distances (e.g., 100 km). Site database work was performed within the context of the NGA-West 2 project. Starting with the site database from original (2008) NGA project (last edited in 2006), we provided site classifications for 2538 new sites and re-classifications of previous sites. The principal site parameter is the time-averaged shear wave velocity in the upper 30 m Vs30, which is characterized using measurements where available, and proxy-based relationships otherwise. We improved the documentation and consistency of site descriptors used as proxies for the estimation of Vs30, developed evidence-based protocols for Vs30 estimation from available proxies, and augmented estimates of various basin depth parameters. Site factors typically have a small-strain site amplification that captures impedance and resonance effects coupled with nonlinear components. Site factors in current NEHRP Provisions are empirically-derived at relatively small ground motion levels and feature simulation-based nonlinearity. We show that current NEHRP site factors have discrepancies with respect to the site terms in the original NGA GMPEs both in the linear site amplification (especially for Classes B, C, D, and E) and the degree of nonlinearity (Classes C and D). We analyzed the NGA-West 2 dataset and simulation-based models for site amplification to develop a new model. The model has linear and nonlinear additive components. The linear component is fully empirical, being derived from worldwide ground motion data (regional effects were examined but found to not be sufficiently important to be included in the model). The model features linear Vs30-scaling in a log-log sense below a corner velocity (Vc), and no Vs30-scaling for velocities faster than Vc. The nonlinear component is developed from consideration of empirical data analysis and simulation results within a consistent context. The resulting nonlinearity operates principally at short periods and soft soils. This model is suitable for use as a site term in GMPEs and was applied to develop a proposal for updating the NEHRP site factors. The recommended factors remove a discrepancy between the reference condition used in the site factors and the national seismic hazard maps published by USGS. We have developed empirical equations for predicting the average horizontal component of earthquake ground motions from active crustal region earthquakes worldwide. The equations build upon a previous ground-motion model by Boore and Atkinson in 2008. Significant new features of the proposed GMPEs include: modified site terms; a modified magnitude scaling function that produces a higher degree of saturation at large magnitude for high-frequency ground motions; region-specific apparent anelastic attenuation term; basin depth correction factors that are centered on the average level of basin amplification conditional on Vs30; standard deviation terms that depend on M for between-event standard deviations and M-1, Rjb and Vs30-dependent within-event standard deviations. The resulting equations are applicable for events over a magnitude range of 3 to 8.5 for strike-slip or reverse-slip events (M3 to 8 for normal slip events), distance range up to 400 km, and site conditions ranging from Vs30 = 150 to 1500 m/s. The equations are useful for prediction of the ground motion i̲ntensity m̲easures (IMs) PGA, PGV, and PSA at periods T = 0 to 10 sec.

Download or read book Strong Ground Motion Seismology written by Mustafa Özder Erdik and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 609 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains selected papers presented at the NATO Advanced Study Institute on "Strong Ground Motion Seismology", held in Ankara, Turkey between June 10 and 21, 1985. The strong ground motion resulting from a major earthquake determines the level of the seismic hazard to enable earthquake engineers to assess the structural performance and the consecutive risks to the property and life, as well as providing detailed information to seismologists about its source mechanism. From the earthquake engineering point the main problem is the specification of a design level ground motion for a given source-site-structure-economic life and risk combination through deterministic and probabilistic approaches. In seismology the strong motion data provide the high frequency information to determine the rupture process and the complexity of the source mechanism. The effects of the propagation path on the strong ground motion is a research area receiving sub stantial attenuation both from earthquake engineers and seismologists. The Institute provided a venue for the treatment of the subject matter by a series of lectures on earthquake source models and near field theories; effects of propagation paths and site conditions, numerical and empirical methods for prediction; data acquisition and analysis; hazard assessment and engineering application.

Download or read book Geotechnical Earthquake Engineering written by Milutin Srbulov and published by Springer Science & Business Media. This book was released on 2008-09-19 with total page 263 pages. Available in PDF, EPUB and Kindle. Book excerpt: ... "Included on the Choice list with the outstanding academic Earth Sciences titles 2008" ... This volume describes simplified dynamic analyses that bridge the gap between the rather limited provisions of design codes and the rather eclectic methods used in sophisticated analyses. Graphs and spreadsheets are included for the ease and speed of use of simplified analyses of: soil slope (in)stability and displacements caused by earthquakes, sand liquefaction and flow caused by earthquakes, dynamic soil-foundation interaction, bearing capacity and additional settlement of shallow foundations, earthquake motion effects on tunnels and shafts, frequent liquefaction potential mitigation measures. A number of comments on the assumptions used in different methods, limitation and factors affecting the results are given. Several case histories are also included in the appendices in order to assess the accuracy and usefulness of the simplified methods. Audience This work is of interest to geotechnical engineers, engineering geologists, earthquake engineers and students.

Download or read book Technical Report Characterization of Ground Motions During the Northridge Earthquake of January 17 1994 written by Paul Sommerville and published by . This book was released on 1995 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Empirical Equations Describing Attenuation of Peaks of Strong Ground Motion in Terms of Magnitude Distance Path Effects and Site Conditions written by Vincent W. Lee and published by . This book was released on 1995 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Stochastic Model for Earthquake Ground Motion Using Wavelet Packets written by Yoshifumi Yamamoto and published by Stanford University. This book was released on 2011 with total page 329 pages. Available in PDF, EPUB and Kindle. Book excerpt: For performance-based design, nonlinear dynamic structural analysis for various types of input ground motions is required. Stochastic (simulated) ground motions are sometimes useful as input motions, because unlike recorded motions they are not limited in number and because their properties can be varied systematically to study the impact of ground motion properties on structural response. This dissertation describes an approach by which the wavelet packet transform can be used to characterize complex time-varying earthquake ground motions, and it illustrates the potential benefits of such an approach in a variety of earthquake engineering applications. The proposed model is based on Thr´ainsson and Kiremidjian (2002), which use Fourier amplitudes and phase differences to simulate ground motions and attenuation models to their model parameters. We extend their model using wavelet packet transform since it can control the time and frequency characteristic of time series. The time- and frequency-varying properties of real ground motions can be captured using wavelet packets, so a model is developed that requires only 13 parameters to describe a given ground motion. These 13 parameters are then related to seismological variables such as earthquake magnitude, distance, and site condition, through regression analysis that captures trends in mean values, standard deviations and correlations of these parameters observed in a large database of recorded strong ground motions. The resulting regression equations then form a model that can be used to predict ground motions for a future earthquake scenario; this model is analogous to widely used empirical ground motion prediction models (formerly called "attenuation models") except that this model predicts entire time series rather than only response spectra. The ground motions produced using this predictive model are explored in detail, and are shown to have elastic response spectra, inelastic response spectra, durations, mean periods, etc., that are consistent in both mean and variability to existing published predictive models for those properties. That consistency allows the proposed model to be used in place of existing models for probabilistic seismic hazard analysis (PSHA) calculations. This new way to calculate PSHA is termed "simulation-based probabilistic seismic hazard analysis" and it allows a deeper understanding of ground motion hazard and hazard deaggregation than is possible with traditional PSHA because it produces a suite of potential ground motion time histories rather than simply a distribution of response spectra. The potential benefits of this approach are demonstrated and explored in detail. Taking this analysis even further, this suite of time histories can be used as input for nonlinear dynamic analysis of structures, to perform a risk analysis (i.e., "probabilistic seismic demand analysis") that allows computation of the probability of the structure exceeding some level of response in a future earthquake. These risk calculations are often performed today using small sets of scaled recorded ground motions, but that approach requires a variety of assumptions regarding important properties of ground motions, the impacts of ground motion scaling, etc. The approach proposed here facilitates examination of those assumptions, and provides a variety of other relevant information not obtainable by that traditional approach.

Download or read book Proceedings of the 7th International Conference on Earthquake Engineering and Seismology written by Murat Altug Erberik and published by Springer Nature. This book was released on with total page 590 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measuring Modeling and Predicting the Seismic Site Effect written by Yefei Ren and published by Frontiers Media SA. This book was released on 2024-01-25 with total page 297 pages. Available in PDF, EPUB and Kindle. Book excerpt: As recognized universally by both seismology and earthquake engineering communities, the amplitude and frequency content of ground motions are influenced by local site effects, including the effects of near-surface geologic materials, surface topographic and basin effects, and so on. Strong linkage between seismic site effect and earthquake damage has been commonly demonstrated from many past earthquakes. Therefore, quantitative and reliable evaluation of the seismic site effect is one of the crucial aspects in seismic hazard assessment and risk mitigation. With the significant advancement of modern seismic monitoring networks and arrays, huge amounts of high-quality seismic records are now being accumulated. This encourages us to measure the site responses and its associated uncertainty for selected seismic stations by some record-dependent approaches, such as horizontal-to-vertical spectral ratio (HVSR) measurements, generalized spectral inversion (GIT) methods, etc. Machine learning techniques also show significant promise in characterization of the near-surface geologic properties and prediction of site response. These data-driven approaches help us to better understand the physics of spatial and temporal variabilities of ground motions. Due to more and more site-specific data being captured, invoking non-ergodic assumptions in seismic response analysis has recently been a topic of great interest in the community. For specific site response analysis, numerical simulations are carried out to model the dynamic process of seismic waves propagating and scattering in the subsurface strata. With development of modeling capacity, great efforts have been taken to evaluate quantitatively the complex 2D and 3D effects on seismic site response.

Download or read book NUREG CR written by U.S. Nuclear Regulatory Commission and published by . This book was released on 1979 with total page 580 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Methods to Develop Site Specific Spectra and a Review of the Important Parameters that Influence the Spectra written by D. L. Bernreuter and published by . This book was released on 1979 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Geological Survey Professional Paper written by and published by . This book was released on 1979 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book U S Geological Survey Professional Paper written by and published by . This book was released on 1984 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Continental Intraplate Earthquakes written by Seth Stein and published by Geological Society of America. This book was released on 2007-01-01 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This volume brings together a sampling of research addressing issues of continental intraplate earthquakes, including a core of papers from special sessions held at the spring 2004 Joint Assembly of the American and Canadian Geophysical Unions in Montreal. Papers address the broad related topics of the science, hazard, and policy issues of large continental intraplate earthquakes in a worldwide context. One group of papers addresses aspects of the primary scientific issue--where are these earthquakes and what causes them? Answering this question is crucial to determining whether they will continue there or migrate elsewhere. A second group of papers addresses the challenge of assessing the hazard posed by intraplate earthquakes. Although it may be a very long time before the scientific issues are resolved, the progress being made is helping attempts to estimate the probability, size, and shaking of future earthquakes, and the uncertainty of the results. A third group of papers explores the question of how society should mitigate the possible effects of future large continental intraplate earthquakes. Communities around the world face the challenge of deciding how to address this rare, but real, hazard, given the wide range of other societal needs. Continental intraplate earthquakes will remain a challenge to seismologists, earthquake engineers, policy makers, and the public for years to come, but significant progress toward understanding and addressing this challenge is now being made."--Publisher's website.

Download or read book Analytical Methods in Petroleum Upstream Applications written by Cesar Ovalles and published by CRC Press. This book was released on 2015-04-02 with total page 1351 pages. Available in PDF, EPUB and Kindle. Book excerpt: Effective measurement of the composition and properties of petroleum is essential for its exploration, production, and refining; however, new technologies and methodologies are not adequately documented in much of the current literature. Analytical Methods in Petroleum Upstream Applications explores advances in the analytical methods and instrumentation that allow more accurate determination of the components, classes of compounds, properties, and features of petroleum and its fractions. Recognized experts explore a host of topics, including: A petroleum molecular composition continuity model as a context for other analytical measurements A modern modular sampling system for use in the lab or the process area to collect and control samples for subsequent analysis The importance of oil-in-water measurements and monitoring The chemical and physical properties of heavy oils, their fractions, and products from their upgrading Analytical measurements using gas chromatography and nuclear magnetic resonance (NMR) applications Asphaltene and heavy ends analysis Chemometrics and modeling approaches for understanding petroleum composition and properties to improve upstream, midstream, and downstream operations Due to the renaissance of gas and oil production in North America, interest has grown in analytical methods for a wide range of applications. The understanding provided in this text is designed to help chemists, geologists, and chemical and petroleum engineers make more accurate estimates of the crude value to specific refinery configurations, providing insight into optimum development and extraction schemes.

Download or read book Spatial Variation of Seismic Ground Motions written by Aspasia Zerva and published by CRC Press. This book was released on 2016-04-19 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt: The spatial variation of seismic ground motions denotes the differences in the seismic time histories at various locations on the ground surface. This text focuses on the spatial variability of the motions that is caused by the propagation of the waveforms from the earthquake source through the earth strata to the ground surface, and it brings toge

Download or read book Seismic Hazard and Risk Analysis written by Jack Baker and published by Cambridge University Press. This book was released on 2021-10-21 with total page 596 pages. Available in PDF, EPUB and Kindle. Book excerpt: Seismic hazard and risk analyses underpin the loadings prescribed by engineering design codes, the decisions by asset owners to retrofit structures, the pricing of insurance policies, and many other activities. This is a comprehensive overview of the principles and procedures behind seismic hazard and risk analysis. It enables readers to understand best practises and future research directions. Early chapters cover the essential elements and concepts of seismic hazard and risk analysis, while later chapters shift focus to more advanced topics. Each chapter includes worked examples and problem sets for which full solutions are provided online. Appendices provide relevant background in probability and statistics. Computer codes are also available online to help replicate specific calculations and demonstrate the implementation of various methods. This is a valuable reference for upper level students and practitioners in civil engineering, and earth scientists interested in engineering seismology.