The Encyclopedia of Earthquake Engineering is designed to be the authoritative and comprehensive reference covering all major aspects of the science of earthquake engineering, specifically focusing on the interaction between earthquakes and infrastructure. The encyclopedia comprises approximately 300 contributions. Since earthquake engineering deals with the interaction between earthquake disturbances and the built infrastructure, the emphasis is on basic design processes important to both non-specialists and engineers so that readers become suitably well informed without needing to deal with the details of specialist understanding. The encyclopedia’s content provides technically-inclined and informed readers about the ways in which earthquakes can affect our infrastructure and how engineers would go about designing against, mitigating and remediating these effects. The coverage ranges from buildings, foundations, underground construction, lifelines and bridges, roads, embankments and slopes. The encyclopedia also aims to provide cross-disciplinary and cross-domain information to domain-experts. This is the first single reference encyclopedia of this breadth and scope that brings together the science, engineering and technological aspects of earthquakes and structures.

The Encyclopedia of Earthquake Engineering is designed to be the authoritative and comprehensive reference covering all major aspects of the science of earthquake engineering, specifically focusing on the interaction between earthquakes and infrastructure. The encyclopedia comprises approximately 300 contributions. Since earthquake engineering deals with the interaction between earthquake disturbances and the built infrastructure, the emphasis is on basic design processes important to both non-specialists and engineers so that readers become suitably well informed without needing to deal with the details of specialist understanding. The encyclopedia’s content provides technically-inclined and informed readers about the ways in which earthquakes can affect our infrastructure and how engineers would go about designing against, mitigating and remediating these effects. The coverage ranges from buildings, foundations, underground construction, lifelines and bridges, roads, embankments and slopes. The encyclopedia also aims to provide cross-disciplinary and cross-domain information to domain-experts. This is the first single reference encyclopedia of this breadth and scope that brings together the science, engineering and technological aspects of earthquakes and structures.

The Encyclopedia of Earthquake Engineering is designed to be the authoritative and comprehensive reference covering all major aspects of the science of earthquake engineering, specifically focusing on the interaction between earthquakes and infrastructure. The encyclopedia comprises approximately 300 contributions. Since earthquake engineering deals with the interaction between earthquake disturbances and the built infrastructure, the emphasis is on basic design processes important to both non-specialists and engineers so that readers become suitably well informed without needing to deal with the details of specialist understanding. The encyclopedia’s content provides technically-inclined and informed readers about the ways in which earthquakes can affect our infrastructure and how engineers would go about designing against, mitigating and remediating these effects. The coverage ranges from buildings, foundations, underground construction, lifelines and bridges, roads, embankments and slopes. The encyclopedia also aims to provide cross-disciplinary and cross-domain information to domain-experts. This is the first single reference encyclopedia of this breadth and scope that brings together the science, engineering and technological aspects of earthquakes and structures.

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.

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.

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.

Accurate prediction of strong ground motion is central to seismic hazard analysis in order to estimate losses during major earthquakes. Ground motion simulations are essential to seismic ground motion prediction, especially for locations of infrequent observations, such as large magnitude and short distance events, where simulations can provide a viable alternative to data. Therefore, enhancement and validation of ground motion simulations, the primary goal of this dissertation, are highly desirable. In Chapter 2, we quantify the effects of four important factors on ground motions from large normal-faulting earthquakes on the Wasatch fault in the Salt Lake Basin: rupture direction, location on the hanging wall versus the footwall, deep 3D basin structure, and the distance from the rupture in the near field range. In Chapter 3, we attempt to validate the presence of several proposed waveguides in the Los Angeles area using 3D simulations and observed data from ambient noise. Here, we compare the numerical and empirical surface-to-surface Green tensors for virtual sources located on the San Andreas Fault. The regions of large peak motions caused by waveguide focusing in the simulations show generally good agreement with increases in the Green tensor amplitudes, supporting the presence of two separate waveguides in greater Los Angeles. In Chapters 4 and 5, we develop an empirical frequency-dependent spatial ground motion correlation model and methods to rectify simulation techniques that otherwise produce synthetic time histories deficient in inter-frequency and spatial correlation structure. The methods are tested using a hybrid deterministic-stochastic broadband ground motion generation module, where our method reproduces the empirical correlations well for a large number of realizations without biasing the fit of the median of the spectral accelerations to data. We find that the best fit of the inter-frequency correlation to data is obtained assuming that the horizontal components are correlated with a correlation coefficient of about 0.7.