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Book Ground Motion Simulation Based on Fault Rupture Modelling for Seismic Hazard Assessment in Site Evaluation for Nuclear Installations

Download or read book Ground Motion Simulation Based on Fault Rupture Modelling for Seismic Hazard Assessment in Site Evaluation for Nuclear Installations written by International Atomic Energy Agency and published by Safety Report. This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Explaining the principles that underlie strong ground motion simulation, this publication describes various methods for simulating strong ground motions, and presents some examples of strong ground motion simulations using fault rupture modelling. The detailed guidelines and practical tools presented in this Safety Report will be of value to researchers, operating organizations, regulatory bodies, vendors and technical support organizations in the areas of seismic hazard evaluation of nuclear installations. The information provided will also be of great importance for seismic hazard assessments following the Fukushima Daiichi nuclear power plant accident.

Book Best Practices in Physics based Fault Rupture Models for Seismic Hazard Assessment of Nuclear Installations

Download or read book Best Practices in Physics based Fault Rupture Models for Seismic Hazard Assessment of Nuclear Installations written by Luis A. Dalguer and published by Birkhäuser. This book was released on 2018-01-02 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume collects several extended articles from the first workshop on Best Practices in Physics-based Fault Rupture Models for Seismic Hazard Assessment of Nuclear Installations (BestPSHANI). Held in 2015, the workshop was organized by the IAEA to disseminate the use of physics-based fault-rupture models for ground motion prediction in seismic hazard assessments (SHA). The book also presents a number of new contributions on topics ranging from the seismological aspects of earthquake cycle simulations for source scaling evaluation, seismic source characterization, source inversion and physics-based ground motion modeling to engineering applications of simulated ground motion for the analysis of seismic response of structures. Further, it includes papers describing current practices for assessing seismic hazard in terms of nuclear safety in low seismicity areas, and proposals for physics-based hazard assessment for critical structures near large earthquakes. The papers validate and verify the models by comparing synthetic results with observed data and empirical models. The book is a valuable resource for scientists, engineers, students and practitioners involved in all aspects of SHA.

Book Seismic Hazards in Site Evaluation for Nuclear Installations

Download or read book Seismic Hazards in Site Evaluation for Nuclear Installations written by IAEA and published by International Atomic Energy Agency. This book was released on 2022-01-19 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Safety Guide supersedes the 2010 edition of IAEA Safety Standards Series No. SSG-9. It takes account of recently gained knowledge and practices developed by Member States related to seismic hazards, especially lessons from the Fukushima Daiichi accident. It also addresses concomitant events associated with earthquakes, such as tsunamis. The revision provides a clearer separation between the process for assessing the seismic hazards at a specific nuclear installation site and the process for defining the related basis for design and safety assessment of the nuclear installation. Thus, it bridges gaps and avoids undue overlap of the two processes, which correspond to and are performed at different stages of siting of the nuclear installation.

Book Best Practices in Physics based Fault Rupture Models for Seismic Hazard Assessment of Nuclear Installations

Download or read book Best Practices in Physics based Fault Rupture Models for Seismic Hazard Assessment of Nuclear Installations written by Luis A. Dalguer and published by Birkhäuser. This book was released on 2017-12-20 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume collects several extended articles from the first workshop on Best Practices in Physics-based Fault Rupture Models for Seismic Hazard Assessment of Nuclear Installations (BestPSHANI). Held in 2015, the workshop was organized by the IAEA to disseminate the use of physics-based fault-rupture models for ground motion prediction in seismic hazard assessments (SHA). The book also presents a number of new contributions on topics ranging from the seismological aspects of earthquake cycle simulations for source scaling evaluation, seismic source characterization, source inversion and physics-based ground motion modeling to engineering applications of simulated ground motion for the analysis of seismic response of structures. Further, it includes papers describing current practices for assessing seismic hazard in terms of nuclear safety in low seismicity areas, and proposals for physics-based hazard assessment for critical structures near large earthquakes. The papers validate and verify the models by comparing synthetic results with observed data and empirical models. The book is a valuable resource for scientists, engineers, students and practitioners involved in all aspects of SHA.

Book Earthquake Engineering for Nuclear Facilities

Download or read book Earthquake Engineering for Nuclear Facilities written by Masanori Hamada and published by Springer. This book was released on 2016-12-12 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a comprehensive compilation of earthquake- and tsunami-related technologies and knowledge for the design and construction of nuclear facilities. As such, it covers a wide range of fields including civil engineering, architecture, geotechnical engineering, mechanical engineering, and nuclear engineering, for the development of new technologies providing greater resistance against earthquakes and tsunamis. It is crucial both for students of nuclear energy courses and for young engineers in nuclear power generation industries to understand the basics and principles of earthquake- and tsunami-resistant design of nuclear facilities. In Part I, "Seismic Design of Nuclear Power Plants", the design of nuclear power plants to withstand earthquakes and tsunamis is explained, focusing on buildings, equipment's, and civil engineering structures. In Part II, "Basics of Earthquake Engineering", fundamental knowledge of earthquakes and tsunamis as well as the dynamic response of structures and foundation ground are explained.

Book Ground Motion Simulations

Download or read book Ground Motion Simulations written by Lynne Schleiffarth Burks and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Engineers use earthquake ground motions for a variety of reasons, including seismic hazard assessment, calibration of ground motion prediction equations (GMPEs), and input to nonlinear response history analysis. These analyses require a significant number of ground motions and for some scenarios, such as earthquakes with large magnitudes and short distances, it may be difficult to obtain a sufficient number of ground motion recordings. When sufficient recordings do not exist, engineers modify available recordings using scaling or spectrum matching, or they use ground motion simulations. Ground motion simulations have existed for decades, but recent advances in simulation methods due to improved source characterization and wave propagation, coupled with increased computing power, have increased potential benefits for engineers. But before simulations can be used in engineering applications, simulations must be accessible and consistent with natural observations. This dissertation contributes to the latter issue, and it investigates the application of simulations to specific engineering problems. The Southern California Earthquake Center (SCEC) Broadband Platform (BBP) is an open-source software distribution that enables third-party users to simulate ground motions using research code contributed by model developers. Because the BBP allows users to compute their own simulations with little knowledge of the underlying implementation and it ensures that all calculations are reproducible, it is extremely valuable for simulation validation and engineering applications. In this dissertation, the BBP is evaluated as a simulation generation tool from an engineering perspective. Ground motions are simulated to study parameters of engineering interest, such as high-frequency variability, near-fault ground motions, and local site response. Though some parameters need further development, such as site response (which is currently implemented using simple empirical amplification), the BBP proves to be an effective tool for facilitating these types of engineering studies. This dissertation proposes a simulation validation framework based on simple and robust proxies for the response of more complicated structures. We compile a list of proxies with robust empirical models that are insensitive to changes in earthquake scenario and do not rely on extrapolation for rarely observed events. Because predictions of these proxies are reliable under a variety of earthquake events, we can confidently compare them with simulations. The proposed proxies include correlation of epsilon across periods, ratio of maximum to median response across horizontal orientations, and ratio of inelastic to elastic displacement. The validation framework is applied to example simulations and successfully exposes some parameters that need work, such as variability and correlation of spectral acceleration. Finally, this dissertation investigates the application of simulations to response history analysis and fling-step characterization. A 3D nonlinear structural model is analyzed using recordings and simulations with similar elastic response spectra. The structural performance and resulting design decisions are similar, indicating that simulations are effective for response history analysis subject to certain conditions. To investigate fling-step, we extract fling pulses from a large set of simulations. Extracted fling properties such as amplitude and period are then compared to specially-processed recordings and relevant empirical models for surface displacement and pulse period. Reasonably good agreement is found between simulations, recordings, and empirical models. In general, ground motion simulations are found to be an effective alternative or supplement to recordings in several engineering applications. Because simulation methods are still developing, this work is not intended as an evaluation of existing methods, but rather as a development of procedures that can be used in ongoing work.

Book Earthquake Geotechnical Engineering for Protection and Development of Environment and Constructions

Download or read book Earthquake Geotechnical Engineering for Protection and Development of Environment and Constructions written by Francesco Silvestri and published by CRC Press. This book was released on 2019-07-19 with total page 8083 pages. Available in PDF, EPUB and Kindle. Book excerpt: Earthquake Geotechnical Engineering for Protection and Development of Environment and Constructions contains invited, keynote and theme lectures and regular papers presented at the 7th International Conference on Earthquake Geotechnical Engineering (Rome, Italy, 17-20 June 2019. The contributions deal with recent developments and advancements as well as case histories, field monitoring, experimental characterization, physical and analytical modelling, and applications related to the variety of environmental phenomena induced by earthquakes in soils and their effects on engineered systems interacting with them. The book is divided in the sections below: Invited papers Keynote papers Theme lectures Special Session on Large Scale Testing Special Session on Liquefact Projects Special Session on Lessons learned from recent earthquakes Special Session on the Central Italy earthquake Regular papers Earthquake Geotechnical Engineering for Protection and Development of Environment and Constructions provides a significant up-to-date collection of recent experiences and developments, and aims at engineers, geologists and seismologists, consultants, public and private contractors, local national and international authorities, and to all those involved in research and practice related to Earthquake Geotechnical Engineering.

Book Diffuse Seismicity in Seismic Hazard Assessment for Site Evaluation of Nuclear Installations

Download or read book Diffuse Seismicity in Seismic Hazard Assessment for Site Evaluation of Nuclear Installations written by International Atomic Energy Agency and published by IAEA Safety Report Series No.. This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Diffuse seismicity refers to earthquakes occurring in locations where no apparent correlation can be made with any causative faults. This publication provides guidance for addressing the seismic hazard from diffuse seismicity in a manner consistent with internationally recognized practices and with reference to relevant IAEA safety standards.

Book Stochastic Modeling and Simulation of Near Fault Ground Motions for Performance Based Earthquake Engineering

Download or read book Stochastic Modeling and Simulation of Near Fault Ground Motions for Performance Based Earthquake Engineering written by Mayssa Dabaghi and published by . This book was released on 2014 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive parameterized stochastic model of near-fault ground motions in two orthogonal horizontal directions is developed. The proposed model uniquely combines several existing and new sub-models to represent major characteristics of recorded near-fault ground motions. These characteristics include near-fault effects of directivity and fling step; temporal and spectral non-stationarity; intensity, duration and frequency content characteristics; directionality of components, as well as the natural variability of motions for a given earthquake and site scenario. By fitting the model to a database of recorded near-fault ground motions with known earthquake source and site characteristics, empirical "observations" of the model parameters are obtained. These observations are used to develop predictive equations for the model parameters in terms of a small number of earthquake source and site characteristics. Functional forms for the predictive equations that are consistent with seismological theory are employed. A site-based simulation procedure that employs the proposed stochastic model and predictive equations is developed to generate synthetic near-fault ground motions at a site. The procedure is formulated in terms of information about the earthquake design scenario that is normally available to a design engineer. Not all near-fault ground motions contain a forward directivity pulse, even when the conditions for such a pulse are favorable. The proposed procedure produces pulselike and non-pulselike motions in the same proportions as they naturally occur among recorded near-fault ground motions for a given design scenario. The proposed models and simulation procedure are validated by several means. Synthetic ground motion time series with fitted parameter values are compared with the corresponding recorded motions. The proposed empirical predictive relations are compared to similar relations available in the literature. The overall simulation procedure is validated by comparing suites of synthetic ground motions generated for given earthquake source and site characteristics to the ground motion prediction equations (GMPEs) developed as part of phase 2 of the Next Generation Attenuation (NGA) program, (NGA-West2, see, e.g., Campbell and Bozorgnia, 2014). Comparison is made in terms of the estimated median level and variability of elastic ground motion response spectra. The use of synthetic motions in addition to or in place of recorded motions is desirable in performance-based earthquake engineering (PBEE) applications, particularly when recorded motions are scarce or when they are unavailable for a specified design scenario. As a demonstrative application, synthetic motions from the proposed simulation procedure are used to perform probabilistic seismic hazard analysis (PSHA) for a near-fault site. The analysis shows that the hazard at a near-fault site is underestimated when the ground motion model used does not properly account for the possibility of pulselike motions due to the directivity effect.

Book Earthquakes

    Book Details:
  • Author : Taher Zouaghi
  • Publisher : BoD – Books on Demand
  • Release : 2017-02-01
  • ISBN : 953512885X
  • Pages : 390 pages

Download or read book Earthquakes written by Taher Zouaghi and published by BoD – Books on Demand. This book was released on 2017-02-01 with total page 390 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is devoted to diverse aspects of earthquake researches, especially to new achievements in seismicity that involves geosciences, assessment, and mitigation. Chapters contain advanced materials of detailed engineering investigations, which can help more clearly appreciate, predict, and manage different earthquake processes. Different research themes for diverse areas in the world are developed here, highlighting new methods of studies that lead to new results and models, which could be helpful for the earthquake risk. The presented and developed themes mainly concern wave's characterization and decomposition, recent seismic activity, assessment-mitigation, and engineering techniques. The book provides the state of the art on recent progress in earthquake engineering and management. The obtained results show a scientific progress that has an international scope and, consequently, should open perspectives to other still unresolved interesting aspects.

Book Seismic Hazard and Risk Assessment

Download or read book Seismic Hazard and Risk Assessment written by Radu Vacareanu and published by Springer. This book was released on 2018-03-21 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains the best contributions presented during the 6th National Conference on Earthquake Engineering and the 2nd National Conference on Earthquake Engineering and Seismology - 6CNIS & 2CNISS, that took place on June 14-17, 2017 in Bucharest - Romania, at the Romanian Academy and Technical University of Civil Engineering of Bucharest. The book offers an updated overview of seismic hazard and risk assessment activities, with an emphasis on recent developments in Romania, a very challenging case study because of its peculiar intermediate-depth seismicity and evolutive code-compliant building stock. Moreover, the book collects input of renowned scientists and professionals from Germany, Greece, Italy, Japan, Netherlands, Portugal, Romania, Spain, Turkey and United Kingdom.The content of the book focuses on seismicity of Romania, geotechnical earthquake engineering, structural analysis and seismic design regulations, innovative solutions for seismic protection of building structures, seismic risk evaluation, resilience-based assessment of structures and management of emergency situations. The sub-chapters consist of the best papers of 6CNIS & 2CNISS selected by the International Advisory and Scientific Committees. The book is targeted at researchers and experts in seismic hazard and risk, evaluation and rehabilitation of buildings and structures, insurers and re-insurers, and decision makers in the field of emergency situations and recovery activities.

Book Utilization of Physics based Simulated Earthquake Ground Motions for Performance Assessment of Tall Buildings

Download or read book Utilization of Physics based Simulated Earthquake Ground Motions for Performance Assessment of Tall Buildings written by Nenad Bijelić and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Databases of recorded motion are limited despite the increasing amount of data collected through strong motion instrumentation programs. Particular lack of data exists for large magnitude events and at close distances as well as on earthquakes in deep sedimentary basins. Additionally, databases of recorded motions are also limited in representation of energy at long periods due to the useable frequencies of recording instruments. This lack of data is currently partially addressed through assumption of ergodicity in development of empirical ground motion prediction equations (GMPEs). Nevertheless, challenges remain for calibration of empirical GMPEs as used in conventional approaches for probabilistic estimation of seismic hazard. At the same time, limited data on strong earthquakes and their effect on structures poses challenges for making reliable risk assessments particularly for tall buildings. For instance, while the collapse safety of tall buildings is likely controlled by large magnitude earthquakes with long du- rations and high long-period content, there are few available recorded ground motions to evaluate these issues. The influence of geologic basins on amplifying ground motion effects raises additional questions. Absent recorded motions from past large magnitude earthquakes, physics-based ground motion simulations provide a viable alternative due to the ability to consider extreme ground motions while being inherently site-specific and explicitly considering instances not well constrained by limited empirical data. This thesis focuses on utilization of physics-based simulated earthquake ground motions for performance assessment of tall buildings with three main goals: (1) developing confidence in the use of simulated ground motions through comparative assessments of recorded and simulated motions; (2) identifying important characteristics of extreme ground motions for col- lapse safety of tall buildings; (3) exploring areas where simulated ground motions provide significant advantages over recorded motions for performance-based engineering. To gain confidence in the use of simulated motions for full performance assessment of tall buildings, a 'similar intensity measure' validation study was performed. Structural responses to ground motions simulated with different methods on the Southern California Earthquake Center (SCEC) Broadband Platform (BBP) are contrasted to recorded motions from PEER NGA database with similar spectral shape and significant durations. Two tall buildings, a 20-story concrete frame and a 42-story concrete core wall building, are analyzed at increasing levels of ground motion intensity, up to structural collapse, to check for statistically significant differences between the responses to simulated and recorded motions. Considered demands include story drift ratios, floor accelerations and collapse response. These comparisons yield similar results in most cases but also reveal instances where certain simulated ground motions can result in biased responses. The source of bias is traced to differences in correlations of spectral values in some of the stochastic ground motion simulations. When the differences in correlations are removed, simulated and recorded motions yield comparable results. Moving beyond validation, the thesis also explored areas where the use of simulated motions provides advantages over approaches based on limited databases of recorded motions for performance-based engineering. One such area is seismic risk in deep sedimentary basins which is studied by examining collapse risk and drift demands of a 20-story archetype tall building utilizing ground motions at four sites in the Los Angeles basin. Seismic demands of the building are calculated form nonlinear structural analyses using large datasets (~500,000 ground motions per site) of unscaled, site-specific simulated seismograms. Seismic hazard and building performance from direct analysis of SCEC CyberShake motions are contrasted with values obtained based on 'conventional' approaches that rely on recorded motions coupled with probabilistic seismic hazard assessments. The analysis shows that, depending on the location of the site within the basin, the two approaches can yield drastically different results. For instance, at a deep basin site the CyberShake-based analysis yields around seven times larger mean annual frequency of collapse ( c) and significantly higher drift demands (e.g. drift demand of 1% is exceeded around three times more frequently) compared to the conventional approach. Both the hazard as well as the spectral shapes of the motions are shown to drive the differences in responses. Deaggregation of collapse risk is performed to identify the relative contributions of earthquake fault ruptures, linking building responses with specific seismograms and contrasting collapse risk with hazard. The effect of earthquake ground motions in deep sedimentary basins on structural collapse risk is further studied through the use of CyberShake earthquake simulations in the Los Angeles basin. Distinctive waveform characteristics of deep basin seismograms are used to classify the ground motions into several archetype groups, and the damaging influence of the basin effects are evaluated by comparing nonlinear structural responses under comparable basin and non-basin ground motions. The deep basin ground motions are observed to have larger durations and spectral intensities than non-basin motions for vibration periods longer than about 1.5 seconds, which can increase the relative structural collapse risk by up to 20 percent between ground motions with otherwise comparable spectral accelerations and significant durations. Two new metrics, termed sustained amplitude response spectra (RSx spectra) and significant duration spectra (Da spectra), are proposed to quantify period-dependent duration effects that are not otherwise captured by conventional ground motion intensity measures. The proposed sustained amplitude response spectra and significant duration spectra show promise for characterizing the damaging effects of long duration features of basin ground motions on buildings and other structures. The large database of CyberShake simulations is utilized to re-examine the relationships between engineering demand parameters and input ground motions on structural response. Focusing on collapse response, machine learning techniques are applied to results of about two million nonlinear time history analyses of an archetype 20-story tall building performed using CyberShake ground motions. The resulting feature selection (based on regularized logistic regression) generally confirms existing understanding of collapse predictors as gained from scaled recorded motions but also reveals the benefit of some novel intensity measures (IMs), in particular the RSx spectral features. In addition, the statistical interrogations of the large collection of hazard-consistent simulations demonstrate the utility of different IMs for collapse predictions in a way that is not possible with recorded motions. A small subset of robust IMs is identified and used in development of an efficient collapse classification algorithm, which is tested on benchmark results from other CyberShake sites. The classification algorithm yields promising results for application to regional risk assessment of building performance.

Book Seismic Hazards in Site Evaluation for Nuclear Installations

Download or read book Seismic Hazards in Site Evaluation for Nuclear Installations written by and published by . This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This Safety Guide supplements the Safety Requirements publication Safety of Fuel Cycle Facilities, and addresses all the stages in the life cycle of uranium fuel fabrication facilities (UFFFs), with emphasis being placed on design and operation. It describes the actions, conditions and procedures for meeting safety requirements and deals specifically with the handling, processing and storage of low enriched uranium that has a 235U concentration of no more than 6%, derived from natural, highly enriched or reprocessed uranium. The publication is intended to be of use to designers, operating organizations and regulators to ensure the safety of UFFFs."--Provided by publisher.

Book Ground Motion Simulation Validation for Building Design and Response Assessment

Download or read book Ground Motion Simulation Validation for Building Design and Response Assessment written by Peng Zhong and published by . This book was released on 2016 with total page 199 pages. Available in PDF, EPUB and Kindle. Book excerpt: Earthquake ground motion records are used as inputs for seismic hazard analysis, development of ground motion prediction equations and nonlinear response history analysis of structures. Real records from past earthquake events have traditionally been recognized as the best representation of seismic input to these analysis. However, our current way of implementing recorded ground motions is poorly constrained and suffers from the paucity of certain condition ground motions, such as the one with short distance and large magnitude. Meanwhile, even though the scaled ground motion is capable of matching the target spectrum, the content of frequency domain and ground motion parameters become unrealistic. With the rapid growth of computational ability and efficiency of computers, simulated ground motion can be an alternative to provide detailed and accurate prediction of earthquake effect. At the same time, simulated ground motions can provide a better representation of the whole ground motion generation process, such as fault rupture, wave propagation phenomena, and site response characterization. Hence, the aforementioned disadvantage of recorded ground motion can be overcame.Despite ground motion simulations have existed for decades, and the design code, such as ASCE/SEI 7-10 (ASCE, 2010), allow use of simulated ground motions for engineering practice, engineers still worried about the stability in ground motion simulation process and similarity between response of engineered structures to similar simulated and recorded ground motions. In order to draw simulated ground motions into engineering applications and make them practical, this dissertation is making contribution to address this issue. Simulated ground motions have to be validated and compared with recorded ground motions to prove their equivalence in engineering applications.This dissertation proposes a simulation validation framework. First step: Identify ground motion waveform parameters that well correlate with response of Multi-Degree of Freedom (MDOF) buildings and bridges. Second step: Develop goodness-of-fit measures and error functions that can describe the difference between simulated and recorded ground motion waveform characteristics and their effect on MDOF systems. Third step: Device the required update to ground motion simulation methods through which better simulations are possible. Forth step: Assess the current state of simulated ground motions for engineering applications.In general, simulated ground motions are found to be an effective surrogate and replenishment of natural records in engineering applications. However, certain drawbacks are detected, 1) Simulated ground motions are likelihood to mismatch certain ground motion parameters, for example, Arias intensity, duration and so on; 2) Structural behavior resulting from recorded ground motions and simulated ground motions are different. The difference stems from the fact that simulated motions are mostly pulse like motions. Because the simulation methods are still developing, our intent is not ranking or classifying them, but rather to provide feedback to update ground motion simulation techniques such that future simulations are more representative of recorded motions.

Book Using Multi scale Dynamic Rupture Models to Improve Ground Motion Estimates

Download or read book Using Multi scale Dynamic Rupture Models to Improve Ground Motion Estimates written by and published by . This book was released on 2013 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: This project uses dynamic rupture simulations to investigate high-frequency seismic energy generation. The relevant phenomena (frictional breakdown, shear heating, effective normal-stress fluctuations, material damage, etc.) controlling rupture are strongly interacting and span many orders of magnitude in spatial scale, requiring highresolution simulations that couple disparate physical processes (e.g., elastodynamics, thermal weakening, pore-fluid transport, and heat conduction). Compounding the computational challenge, we know that natural faults are not planar, but instead have roughness that can be approximated by power laws potentially leading to large, multiscale fluctuations in normal stress. The capacity to perform 3D rupture simulations that couple these processes will provide guidance for constructing appropriate source models for high-frequency ground motion simulations. The improved rupture models from our multi-scale dynamic rupture simulations will be used to conduct physicsbased (3D waveform modeling-based) probabilistic seismic hazard analysis (PSHA) for California. These calculation will provide numerous important seismic hazard results, including a state-wide extended earthquake rupture forecast with rupture variations for all significant events, a synthetic seismogram catalog for thousands of scenario events and more than 5000 physics-based seismic hazard curves for California.

Book Quantification of Ground Motions by Broadband Simulations

Download or read book Quantification of Ground Motions by Broadband Simulations written by Katrin Kieling and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In many procedures of seismic risk mitigation, ground motion simulations are needed to test systems or improve their effectiveness. For example they may be used to estimate the level of ground shaking caused by future earthquakes. Good physical models for ground motion simulation are also thought to be important for hazard assessment, as they could close gaps in the existing datasets. Since the observed ground motion in nature shows a certain variability, part of which cannot be explained by macroscopic parameters such as magnitude or position of an earthquake, it would be desirable that a good physical model is not only able to produce one single seismogram, but also to reveal this natural variability. In this thesis, I develop a method to model realistic ground motions in a way that is computationally simple to handle, permitting multiple scenario simulations. I focus on two aspects of ground motion modelling. First, I use deterministic wave propagation for the whole frequency range - from static deformation to approximately 10 Hz - but account for source variability by implementing self-similar slip distributions and rough fault interfaces. Second, I scale the source spectrum so that the modelled waveforms represent the correct radiated seismic energy. With this scaling I verify whether the energy magnitude is suitable as an explanatory variable, which characterises the amount of energy radiated at high frequencies - the advantage of the energy magnitude being that it can be deduced from observations, even in real-time. Applications of the developed method for the 2008 Wenchuan (China) earthquake, the 2003 Tokachi-Oki (Japan) earthquake and the 1994 Northridge (California, USA) earthquake show that the fine source discretisations combined with the small scale source variability ensure that high frequencies are satisfactorily introduced, justifying the deterministic wave propagation approach even at high frequencies. I demonstrate that the energy magnitude can be used to calibrate the high-frequency content in ground motion simulations. Because deterministic wave propagation is applied to the whole frequency range, the simulation method permits the quantification of the variability in ground motion due to parametric uncertainties in the source description. A large number of scenario simulations for an M=6 earthquake show that the roughness of the source as well as the distribution of fault dislocations have a minor effect on the simulated variability by diminishing directivity effects, while hypocenter location and rupture velocity more strongly influence the variability. The uncertainty in energy magnitude, however, leads to the largest differences of ground motion amplitude between different events, resulting in a variability which is larger than the one observed. For the presented approach, this dissertation shows (i) the verification of the computational correctness of the code, (ii) the ability to reproduce observed ground motions and (iii) the validation of the simulated ground motion variability. Those three steps are essential to evaluate the suitability of the method for means of seismic risk mitigation.