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UC Berkeley Seismic Guidelines, Appendix II: Ground Motion TimeHistories for the UC Berkeley Campus

Description: Three sets of ten time histories each were developed to represent the ground motions for each of the three return periods. All of the time histories are provided as pairs of fault-normal and fault-parallel components. The ground motion time histories are provided in two forms: unmodified, and spectrally modified to match the probabilistic response spectra. The unmodified time histories can be scaled to match the probabilistic response spectra at a specified period, such as the first mode period of the structure being analyzed, while leaving the shape of the response spectrum unmodified. This approach preserves the particular characteristics of the individual time history, together with the peaks and troughs of its response spectrum. These individual characteristics are modified in the spectrally matched time histories, resulting in a suite of ten time histories (for a given return period) that all have the same response spectrum for a given component (fault normal or fault parallel) that follows the smooth shape of the probabilistic response spectrum.
Date: June 3, 2003
Partner: UNT Libraries Government Documents Department

UC Berkeley Seismic Guidelines, Appendix II: Ground Motion Time Histories for the UC Berkeley Campus

Description: Three sets of ten time histories each were developed to represent the ground motions for each of the three return periods. All of the time histories are provided as pairs of fault-normal and fault-parallel components. The ground motion time histories are provided in two forms: unmodified, and spectrally modified to match the probabilistic response spectra. The unmodified time histories can be scaled to match the probabilistic response spectra at a specified period, such as the first mode period of the structure being analyzed, while leaving the shape of the response spectrum unmodified. This approach preserves the particular characteristics of the individual time history, together with the peaks and troughs of its response spectrum. These individual characteristics are modified in the spectrally matched time histories, resulting in a suite of ten time histories (for a given return period) that all have the same response spectrum for a given component (fault normal or fault parallel) that follows the smooth shape of the probabilistic response spectrum.
Date: June 3, 2003
Creator: Authors, Various
Partner: UNT Libraries Government Documents Department

Comparison of Nonlinear Model Results Using Modified Recorded and Synthetic Ground Motions

Description: A study has been performed that compares results of nonlinear model runs using two sets of earthquake ground motion time histories that have been modified to fit the same design response spectra. The time histories include applicable modified recorded earthquake ground motion time histories and synthetic ground motion time histories. The modified recorded earthquake ground motion time histories are modified from time history records that are selected based on consistent magnitude and distance. The synthetic ground motion time histories are generated using appropriate Fourier amplitude spectrums, Arias intensity, and drift correction. All of the time history modification is performed using the same algorithm to fit the design response spectra. The study provides data to demonstrate that properly managed synthetic ground motion time histories are reasonable for use in nonlinear seismic analysis.
Date: November 1, 2011
Creator: Spears, Robert E. & Wilkins, J. Kevin
Partner: UNT Libraries Government Documents Department

The Response of Long-Span Bridges to Low Frequency, Near-Fault Earthquake Ground Motions

Description: Historical seismic hazard characterizations did not include earthquake ground motion waveforms at frequencies below approximately 0.2 Hz (5 seconds period). This resulted from limitations in early strong motion instrumentation and signal processing techniques, a lack of measurements in the near-field of major earthquakes and therefore no observational awareness, and a delayed understanding in the engineering community of the potential significance of these types of motions. In recent years, there is a growing recognition of the relevance of near-fault, low frequency motions, particularly for long-period structures such as large bridges. This paper describes a computationally based study of the effects of low frequency (long-period) near-fault motions on long-span bridge response. The importance of inclusion of these types of motions for long span cable supported bridges is demonstrated using actual measured broad-band, near-fault motions from large earthquakes.
Date: February 27, 2009
Creator: McCallen, David; Astaneh-Asl, A.; Larsen, S.C. & Hutchings, Larry
Partner: UNT Libraries Government Documents Department

Utilization of near-source video and ground motion in the assessment of seismic source functions from mining explosions

Description: Constraint of the operative physical processes in the source region of mining explosions and the linkage to the generation of seismic waveforms provides the opportunity for controlling ground motion. Development of these physical models can also be used in conjunction with the ground motion data as diagnostics of blasting efficiency. In order to properly address the multi-dimensional aspect of data sets designed to constrain these sources, we are investigating a number of modem visualization tools that have only recently become available with new, high-speed graphical computers that can utilize relatively large data sets. The data sets that are combined in the study of mining explosion sources include near-source ground motion acceleration and velocity records, velocity of detonation measurements in each explosive hole, high speed film, video and shot design information.
Date: April 1, 1995
Creator: Stump, B.W. & Anderson, D.P.
Partner: UNT Libraries Government Documents Department

Seismic studies of the San Francisco-Oakland Bay Bridge

Description: Computational simulation plays a central role in the engineering analysis and design of major bridge structures and accurate simulations are essential for the development of earthquake resistant and economical structural designs. This paper describes new methodologies and computational tools which have recently been developed for simulating earthquake ground motions and the seismic response of cable supported bridges. The simulation tools are described and an example application for an important long-span suspension bridge is demonstrated. The application portion of the study has particular focus on the potential damaging effects of long period displacement pulses and permanent ground displacements which can occur when a bridge is located in the near-field of a major earthquake fault.
Date: August 17, 1999
Creator: Astaneh-Asl, A; Larsen, S & McCallen, D
Partner: UNT Libraries Government Documents Department

Re-alignment: It is the tunnel floor which moves, isn`t it?

Description: It is shown that on the months to years time scale, accelerator tunnels built in compacted geological strata exhibit a movement of the floor systematic (unidirectional) in each point. Attempts to characterize the movement through one global number (a <rms> deviation) based on a random model are conceptionally wrong and can only lead to erroneous design decisions for future accelerators. In the extrapolation limit, differences are especially pronounced for differential movements in the case of short (days) time spans, and for accumulated movements in the case of long (years) time spans.
Date: October 1, 1995
Creator: Pitthan, R.
Partner: UNT Libraries Government Documents Department

Analysis of source spectra, attenuation, and site effects from central and eastern United States earthquakes

Description: This report describes the results from three studies of source spectra, attenuation, and site effects of central and eastern United States earthquakes. In the first study source parameter estimates taken from 27 previous studies were combined to test the assumption that the earthquake stress drop is roughly a constant, independent of earthquake size. 200 estimates of stress drop and seismic moment from eastern North American earthquakes were combined. It was found that the estimated stress drop from the 27 studies increases approximately as the square-root of the seismic moment, from about 3 bars at 10{sup 20} dyne-cm to 690 bars at 10{sup 25} dyne-cm. These results do not support the assumption of a constant stress drop when estimating ground motion parameters from eastern North American earthquakes. In the second study, broadband seismograms recorded by the United States National Seismograph Network and cooperating stations have been analysed to determine Q{sub Lg} as a function of frequency in five regions: the northeastern US, southeastern US, central US, northern Basin and Range, and California and western Nevada. In the third study, using spectral analysis, estimates have been made for the anelastic attenuation of four regional phases, and estimates have been made for the source parameters of 27 earthquakes, including the M{sub b} 5.6, 14 April, 1995, West Texas earthquake.
Date: February 1, 1998
Creator: Lindley, G.
Partner: UNT Libraries Government Documents Department

Validation of a ground motion synthesis and prediction methodology for the 1988, M=6.0, Saguenay Earthquake

Description: We model the 1988, M=6.0, Saguenay earthquake. We utilize an approach that has been developed to predict strong ground motion. this approach involves developing a set of rupture scenarios based upon bounds on rupture parameters. rupture parameters include rupture geometry, hypocenter, rupture roughness, rupture velocity, healing velocity (rise times), slip distribution, asperity size and location, and slip vector. Scenario here refers to specific values of these parameters for an hypothesized earthquake. Synthetic strong ground motion are then generated for each rupture scenario. A sufficient number of scenarios are run to span the variability in strong ground motion due to the source uncertainties. By having a suite of rupture scenarios of hazardous earthquakes for a fixed magnitude and identifying the hazard to the site from the one standard deviation value of engineering parameters we have introduced a probabilistic component to the deterministic hazard calculation, For this study we developed bounds on rupture scenarios from previous research on this earthquake. The time history closest to the observed ground motion was selected as a model for the Saguenay earthquake.
Date: January 1, 1998
Creator: Hutchings, L.; Jarpe, S.; Kasameyer, P. & Foxall, W.
Partner: UNT Libraries Government Documents Department

BOTE model: an analytic approach to predicting ground motion phenomena resulting from underground nuclear explosions

Description: An analytical model (the BOTE model) based upon a superposition of the limiting forms for the outgoing stress wave (i.e., a strong shock at early times decaying to a simple acoustic wave at later times) is presented as a means to describe the groundmotion phenomena resulting from underground nuclear explosions. Taking into account the effects of both the porosity and the water content of the surrounding medium, the BOTE model provides good agreement with both calculated and experimental data for times ranging from tens of microseconds to tens of milliseconds, and for distances ranging out to 350 ft/kt . (auth)
Date: November 1, 1973
Partner: UNT Libraries Government Documents Department

Use of experience data for seismic evaluations at Department of Energy facilities

Description: Seismic evaluations of essential systems and components at Department of Energy (DOE) facilities will be conducted over the next several years. For many of these systems and components, few, if any, seismic requirements applied to the original design, procurement, installation, and maintenance process. Thus the verification of the seismic adequacy of existing systems and components presents a difficult challenge. DOE has undertaken development of the criteria and procedures for these seismic evaluations that will maximize safety benefits in a timely and cost effective manner. As demonstrated in previous applications at DOE facilities and by the experience from the commercial nuclear power industry, use of experience data for these evaluations is the only viable option for most existing systems and components. This paper describes seismic experience data, the needs at DOE facilities, the precedent of application of nuclear power plants and DOE facilities, and the program underway for the seismic verification task ahead for DOE.
Date: December 7, 1994
Creator: Murray, R.C.; Kimball, J.K.; Guzy, D.J. & Hill, J.R.
Partner: UNT Libraries Government Documents Department

A PHYSICAL MODEL OF THE EFFECT OF A SHALLOW WEAK LAYER ON STRONG GROUND MOTION FOR STRIKE-SLIP RUPTURES

Description: We report results of foam-rubber modeling of the effect of a shallow weak layer on ground motion from strike-slip ruptures. Computer modeling of strong ground motion from strike-slip earthquakes has involved somewhat arbitrary assumptions about the nature of slip along the shallow part of the fault (e.g., fixing the slip to be zero along the upper 2 kilometers of the fault plane) in order to match certain strong motion accelerograms. Most modeling studies of earthquake strong ground motion have used what is termed kinematic dislocation modeling. In kinematic modeling the time function for slip on the fault is prescribed, and the response of the layered medium is calculated. Unfortunately, there is no guarantee that the model and the prescribed slip are physically reasonable unless the true nature of the medium and its motions are known ahead of time. There is good reason to believe that in many cases faults are weak along the upper few kilometers of the fault zone and may not be able to maintain high levels of shear strain required for high dynamic energy release during earthquakes. Physical models of faulting, as distinct from numerical or mathematical models, are guaranteed to obey static and dynamic mechanical laws. Foam-rubber modeling studies have been reported in a number of publications. The object of this paper is to present results of physical modeling using a shallow weak layer, in order to verify the physical basis for assuming a long rise time and a reduced high frequency pulse for the slip on the shallow part of faults. It appears a 2-kilometer deep, weak zone along strike-slip faults could indeed reduce the high frequency energy radiated from shallow slip, and that this effect can best be represented by superimposing a small amplitude, short rise-time pulse at the onset of a much longer ...
Date: February 23, 1998
Creator: Brune, James N. & Anooshehpoor, Abdolrasool
Partner: UNT Libraries Government Documents Department

A final focus system for the Next Linear Collider

Description: The final focus of the Next Linear Collider (NLC) demagnifies electron and positron beams of 250--750 GeV energy down to a transverse size of about 2.5 {times} 350 nm{sup 2} at the interaction point (IP). The basic layout, momentum bandwidth, vibration tolerances, wakefield effects, and the tunability of the proposed final focus design are discussed. Also a perspective is given on the crab cavity and on effects of the solenoid field in the interaction region.
Date: June 1, 1995
Creator: Zimmermann, F.; Brown, K.; Emma, P.; Helm, R.; Irwin, J.; Tenenbaum, P. et al.
Partner: UNT Libraries Government Documents Department

Seismic evaluation methods for existing buildings

Description: Recent US Department of Energy natural phenomena hazards mitigation directives require the earthquake reassessment of existing hazardous facilities and general use structures. This applies also to structures located in accordance with the Uniform Building Code in Seismic Zone 0 where usually no consideration is given to seismic design, but where DOE specifies seismic hazard levels. An economical approach for performing such a seismic evaluation, which relies heavily on the use of preexistent structural analysis results is outlined below. Specifically, three different methods are used to estimate the seismic capacity of a building, which is a unit of a building complex located on a site considered low risk to earthquakes. For structures originally not seismically designed, which may not have or be able to prove sufficient capacity to meet new arbitrarily high seismic design requirement and which are located on low-seismicity sites, it may be very cost effective to perform detailed site-specific seismic hazard studies in order to establish the true seismic threat. This is particularly beneficial, to sites with many buildings and facilities to be seismically evaluated.
Date: July 1, 1995
Creator: Hsieh, B.J.
Partner: UNT Libraries Government Documents Department

Detailed summary of the working group on environmental control (T6)

Description: For the next generation of large accelerators, the civil engineering of accelerator tunnels and associated underground enclosures will be a major component of the technical challenge of building such machines. Because of the large scale involved, the engineering will be required to be as cost-effective as possible, and issues such as ground motion and artificial sources of vibration in the environment will need to be carefully considered. installation and alignment of the machine components will be tasks of unprecedented scope, and will require unprecedented precision. Examine in detail the most important and most difficult aspects of these challenges, both from the point of view of performance and cost-effectiveness. In particular, identify what the site requirements are for the different machines under discussion (JLC, NLC, TESLA, VLHC, Muon source), and describe how tunneling methods are affected by them. Identify, for the different types of accelerators, the different length scales that are involved in defining the alignment tolerances, and what are the tolerances over that length scale. Specify the R and D efforts needed to define the scope of the most critical challenges, and prioritize the efforts, in terms of the potential to provide maximal performance and/or cost-effectiveness. Establish a technology-limited time line, and the resource requirements, for the most important of these efforts.
Date: November 21, 2002
Creator: Bialowons, Wilhelm; Laughton, Chris & Seryi, Andrei
Partner: UNT Libraries Government Documents Department

VLHC/NLC slow ground motion studies in Illinois

Description: Since October 1999 we carry out continuous measurements of the slow ground motion on and nearby Fermilab site with a primary goal to provide experimental data for the Very Large Hadron Collider (VLHC) and Next Linear Collider (NLC) projects. Here we give a general description of the experimental set-up, present main results and discuss consequences for the colliders.
Date: July 2, 2001
Creator: al., Vladimir Shiltsev et
Partner: UNT Libraries Government Documents Department

Ground Motion Studies at NSLS II

Description: In this study, an array of vibration measurements at the undisturbed NSLS II site has been performed in order to establish the 'green-field' vibration environment and its spectral characteristics. The interaction of the green-field vibration environment with the NSLS II accelerator structure and the quantification of the storage ring vibration, both in terms of amplitude and spectral content have been assessed through a state-of-the-art wave propagation and scattering analysis. This paper focuses on the wave propagation and scattering aspect as well as on the filtering effects of accelerator structural parameters.
Date: June 23, 2008
Creator: Simos,N.; Fallier, M. & Amick, H.
Partner: UNT Libraries Government Documents Department