Pacific Gas and Electric Company

About: Pacific Gas and Electric Company is a based out in . It is known for research contribution in the topics: Electric power system & Electric power transmission. The organization has 573 authors who have published 596 publications receiving 22772 citations. The organization is also known as: PG&E & Pacific Gas & Electric.

Modification of Empirical Strong Ground Motion Attenuation Relations to Include the Amplitude and Duration Effects of Rupture Directivity

Abstract: Rupture directivity effects cause spatial variations in ground motion amplitude and duration around faults and cause differences between the strike-normal and strike-parallel components of horizontal ground motion amplitudes, which also have spatial variation around the fault. These variations become significant at a period of 0.6 second and generally grow in size with increasing period. We have developed modifications to empirical strong ground motion attenuation relations to account for the effects of rupture directivity on strong motion amplitudes and durations. The modifications are based on an empirical analysis of near-fault data. The ground motion parameters that are modified include the average horizontal response spectral acceleration, the duration of the acceleration time history, and the ratio of strike-normal to strike-parallel spectral acceleration. The parameters upon which the adjustments to average horizontal amplitude and duration depend are the fraction of the fault rupture that occurs on the part of the fault that lies between the hypocenter and the site, and the angle between the fault plane and the path from the hypocenter to the site. Since both of these parameters can be derived from the hypocenter location and the fault geometry, the model of rupture directivity effects on ground motions that we have developed can be directly included in probabilistic seismic hazard calculations. The spectral acceleration is larger for periods longer than 0.6 second, and the duration is smaller, when rupture propagates toward a site. For sites located close to faults, the strike-normal spectral acceleration is larger than the strike-parallel spectral acceleration at periods longer than 0.6 second in a manner that depends on magnitude, distance, and angle. To facilitate the selection of time histories that represent near-fault ground motion conditions in an appropriate manner, we provide a list of near-fault records indicating the rupture directivity parameters that each contains.

Empirical Response Spectral Attenuation Relations for Shallow Crustal Earthquakes

Abstract: Using a database of 655 recordings from 58 earthquakes, empirical response spectral attenuation relations are derived for the average horizontal and vertical component for shallow earthquakes in active tectonic regions. A new feature in this model is the inclusion of a factor to distinguish between ground motions on the hanging wall and footwall of dipping faults. The site response is explicitly allowed to be non-linear with a dependence on the rock peak acceleration level.

Short-term load forecasting

Abstract: This paper discusses the state of the art in short-term load forecasting (STLF), that is, the prediction of the system load over an interval ranging from one hour to one week. The paper reviews the important role of STLF in the on-line scheduling and security functions of an energy management system (EMS). It then discusses the nature of the load and the different factors influencing its behavior. A detailed classification of the types of load modeling and forecasting techniques is presented. Whenever appropriate, the classification is accompanied by recommendations and by references to the literature which support or expand the discussion. The paper also presents a lengthy discussion of practical aspects for the development and usage of STLF models and packages. The annotated bibliography offers a representative selection of the principal publications in the STLF area.

Characterizing Crustal Earthquake Slip Models for the Prediction of Strong Ground Motion

Abstract: INTRODUCTION A large amount of work has been done in recent years to estimate the distribution of slip on the fault surface during earthquakes. Generally, these slip models are derived from longer period ground motions: strong-motion velocity and displacement, and teleseismic velocity seismograms. At these longer periods, ground motions are predominantly deterministic and their waveforms can in general be accurately modeled using simple descriptions of the source and crustal structure. The opposite situation exists for the prediction of high-frequency strong ground motions. Ground motions at high frequencies are predominantly stochastic, and their waveforms in general cannot be accurately modeled using simple descriptions of the source and crustal structure. However, preliminary evidence ( e.g. , Hartzell et al. , 1996; Kamae and Irikura, 1998; Somerville, 1993; Somerville et al ., 1996; Wald et al. , 1988) suggests that variable slip models derived from longer-period ground-motion recordings are relevant for the prediction of higher-frequency ground motions. For...

NGA-West2 Database

Abstract: The NGA-West2 project database expands on its predecessor to include worldwide ground motion data recorded from shallow crustal earthquakes in active tectonic regimes post-2000 and a set of small-t...