145 Matching Results

Search Results

Advanced search parameters have been applied.


Description: M&D Professional Services, Inc. (M&D) is under subcontract to Pacific Northwest National Laboratories (PNNL) to perform seismic analysis of the Hanford Site Double-Shell Tanks (DSTs) in support of a project entitled ''Double-Shell Tank DSV Integrity Project-DST Thermal and Seismic Analyses''. The overall scope of the project is to complete an up-to-date comprehensive analysis of record of the DST System at Hanford in support of Tri-Party Agreement Milestone M-48-14. The thermal and operating loads analysis of the DSTs is documented in Rinker et al. (2004). The work statement provided to M&D (PNNL 2003) required that the seismic analysis of the DST assess the impacts of potentially non-conservative assumptions in previous analyses and account for the additional soil mass due to the as-found soil density increase, the effects of material degradation, additional thermal profiles applied to the full structure including the soil-structure response with the footings, the non-rigid (low frequency) response of the tank roof, the asymmetric seismic-induced soil loading, the structural discontinuity between the concrete tank wall and the support footing and the sloshing of the tank waste. The seismic analysis considers the interaction of the tank with the surrounding soil, and the effects of the primary tank contents. The DST and the surrounding soil are modeled as a system of finite elements. The depth and width of the soil incorporated into the analysis model are sufficient to obtain appropriately accurate analytical results. The analyses required to support the work statement differ from previous analysis of the DSTs in that the soil-structure interaction (SSI) model includes several (nonlinear) contact surfaces in the tank structure, and the contained waste must be modeled explicitly in order to capture the fluid-structure interaction behavior between the primary tank and contained waste. Soil-structure interaction analyses are traditionally solved in the frequency domain, but frequency domain analysis ...
Date: March 14, 2006
Creator: MACKEY, T.C.
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

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


Description: Brookhaven National Laboratory (BNL) undertook an effort to revise the CARES (Computer Analysis for Rapid Evaluation of Structures) program under the auspices of the US Nuclear Regulatory Commission (NRC). The CARES program provided the NRC staff a capability to quickly check the validity and/or accuracy of the soil-structure interaction (SSI) models and associated data received from various applicants. The aim of the current revision was to implement various probabilistic simulation algorithms in CARES (referred hereinafter as P-CARES [1]) for performing the probabilistic site response and soil-structure interaction (SSI) analyses. This paper provides an overview of the development process of P-CARES, including the various probabilistic simulation techniques used to incorporate the effect of site soil uncertainties into the seismic site response and SSI analyses and an improved graphical user interface (GUI).
Date: August 1, 2007
Creator: NIE,J.; XU, J.; COSTANTINO, C. & THOMAS, V.
Partner: UNT Libraries Government Documents Department

Status report on the long-term stability of the Advanced Photon Source.

Description: Table 1 summarizes the average elevation changes and standard deviations as well as the points with the largest changes for each year. On average, hardly any settlements can be detected; however, local changes of +2.90 mm to {minus}2.31 mm have been measured. Looking at the low and high points, the settlement process is slowing down over time. Overall, the settlements observed match the expectations for this type of construction. To date no major realignment of the Advanced Photon Source (APS) storage ring has been necessary. The particle beam tracks with the settlements of the floor as long as these changes occur in a smooth fashion and not as sudden discontinuities [5]. From Figures 6 through 8 it is also apparent that settlements affect larger areas in the storage ring and experiment hall that impact the location of the source point as well as the location of the beamline user equipment. The limiting apertures of the insertion device chambers will make realignment of the APS storage ring a necessity at some point in the future. Currently simulations and machine studies we underway to provide an estimate of tolerable settlement limits before a realignment of certain sections of the storage ring would be required. In conclusion, the APS has been constructed on solid ground with an excellent foundation. Only small settlement changes are being observed; so far they are not impacting the operation of the accelerator. We are continuing to monitor deformations of the APS floor in anticipation of a future realignment of the accelerator components.
Date: September 21, 1998
Creator: Friedsam, H.
Partner: UNT Libraries Government Documents Department

Geologic and geotechnical assessment RFETS Building 371, Rocky Flats, Colorado

Description: This report describes the review and evaluation of the geological, geotechnical and geophysical data supporting the design basis analysis for the Rocky Flats Environmental Test Site (RFETS) Building 371. The primary purpose of the geologic and geotechnical reviews and assessments described herein are to assess the adequacy of the crustal and near surface rock and soil model used in the seismic analysis of Building 371. This review was requested by the RFETS Seismic Evaluation Program. The purpose was to determine the adequacy of data to support the design basis for Building 371, with respect to seismic loading. The objectives required to meet this goal were to: (1) review techniques used to gather data (2) review analysis and interpretations of the data; and (3) make recommendations to gather additional data if required. Where there were questions or inadequacies in data or interpretation, recommendations were made for new data that will support the design basis analysis and operation of Building 371. In addition, recommendations are provided for a geologic and geophysical assessment for a new facility at the Rocky Flats Site.
Date: December 13, 1995
Creator: Maryak, M.E.; Wyatt, D.E.; Bartlett, S.F.; Lewis, M.R. & Lee, R.C.
Partner: UNT Libraries Government Documents Department

Surface measurements of shear wave velocity at the 7-GeV APS site

Description: A knowledge of shear wave speeds as a function of site location and soil depth is fundamental co the vibration study of the 7-GeV Experiment Hall foundation supporting the storage ring magnets, insertion devices, and experiments. Among other things, knowledge of the shear wave speed allows one to calculate the shear modulus of elasticity of the soil using the relationship G pV{sup 2}{sub S} where G is shear modulus of elasticity, p is soil density, and V{sub s} is shear wave speed. The shear modulus, in turn, is one of the most important parameters in performing a dynamic analysis of the response of the foundation to both external excitation (ground motion) and excitation sources internal to the Experiment Hall.
Date: December 1, 1987
Creator: Jendrzejczyk, J.A. & Wambsganss, M.W.
Partner: UNT Libraries Government Documents Department

Seismic response of a nuclear power generation complex including structure-to-structure interaction effects

Description: Seismic responses of the Zion nuclear power generation complex accounting for structure-to-structure interaction effects as predicted by CLASSI and FLUSH Codes are presented in this paper. Two aspects of the multi-structure analyses were considered: the effect of structure-to-structure interaction on structure response and the variability in structure response as predicted by different codes, including structure-to-structure interaction. The effect of structure- to-structure interaction on the response of the Zion reactor building and AFT complex (the auxiliary/fuel-handling/turbine building complex) was assessed by comparing the results of CLASSI analyses with and without interaction between structures. The results show that the reactor building has a very small effect on the AFT complex, but the effect of structure-to-structure interaction on the reactor building from the AFT complex is substantial. A comparison of the reactor building`s response as predicted by CLASSI and FLUSH, structures including structure-to-structure interaction, shows significant differences. Modeling three-dimensional configuration of a complicated power plant structure such as the Zion`s with equivalent two-dimensional models for structure-to-structure interaction analysis requires careful consideration.
Date: May 2, 1997
Creator: Chen, J.C.; Masienikov, O.R. & Johnson, J.J.
Partner: UNT Libraries Government Documents Department

Computation of the seismic stability of earth retaining structures

Description: The purpose of this CRADA project was to evaluate the seismic stability of block retaining wall systems. Retaining wall systems are used extensively in private and commercial developments. This study was designed to develop and demonstrate a computer modeling technology to be used to predict the seismic stability of any block wall system design. The nonlinear finite element computer programs developed at LLNL and employed in the Computational Earthquake Initiative were utilized in this small business CRADA to analyze the seismic stability of the block retaining walls. The unique capability of the LLNL programs to rigorously model frictional contact in a dynamic analysis problem were used in a computer simulation of the dynamic interaction the block wall/soil systems under seismic excitation. Another important application, and the focus of the proposal, was the use of block retaining walls in highway transportation systems to provide a vertical wall to hold back a mass of soil near highway bridges, and at on-ramps and off-ramps. Block retaining walls offered the potential of highway retaining wall construction which was both more flexible and more economical than existing poured-in-place and tilt-up highway retaining wall construction. However, block retaining wall technology was not embraced and utilized in the State of California as a result of seismic stability concerns expressed by Caltrans. Caltrans had an interest in utilizing block wall systems as soil retaining systems for major highway structures in California, but they stated to the block wall manufacturers and the manufacturer's engineering consultants that block retaining walls could not be employed until Caltrans was convinced of the earthquake stability of such systems.
Date: July 30, 1998
Partner: UNT Libraries Government Documents Department


Description: Over the past twenty years, the Nuclear Power Engineering Corporation (NUPEC) of Japan has conducted a series of field model test programs to investigate various aspects of soil-structure interaction (SSI) effects on nuclear power plant structures, including embedment and dynamic structure-soil-structure interaction (SSSI) effects. As part of a collaborative agreement between the US Nuclear Regulatory Commission (NRC) and NUPEC, Brookhaven National Laboratory (BNL) performed a numerical analysis to predict the free field soil profile using industry standard methods and the recorded free field responses to actual earthquake events. This paper describes the BNL free-field analyses, including the methods and the analysis results and their comparison to recorded data in the free field. The free-field soil profiles determined from the BNL analyses are being used for both the embedment and SSSI studies, the results of which will be made available upon their completion.
Date: March 22, 2001
Creator: Xu, J.; Costantino, C.; Hofmayer, C.; Murphy, A.; Chokshi, N. & Kitada, Y.
Partner: UNT Libraries Government Documents Department

Seismic active control by neutral networks

Description: A study on the application of artificial neural networks (ANNs) to active structural control under seismic loads is carried out. The structure considered is a single-degree-of-freedom (SDF) system with an active bracing device. The control force is computed by a trained neural network. The feedforward neural network architecture and an adaptive backpropagation training algorithm is used in the study. The neural net is trained to reproduce the function that represents the response-excitation relationship of the SDF system under seismic loads. The input-output training patterns are generated randomly. In the backpropagation training algorithm, the learning rate is determined by ensuring the decrease of the error function at each epoch. The computer program implemented is validated by solving the classification of the XOR problem. Then, the trained ANN is used to compute the control force according to the control strategy. If the control force exceeds the actuator`s capacity limit, it is set equal to that limit. The concept of the control strategy employed herein is to apply the control force at every time step to cancel the system velocity induced at the preceding time step so that the gradual rhythmic buildup of the response is destroyed. The ground motions considered in the numerical example are the 1940 El Centro earthquake and the 1979 Imperial Valley earthquake in California. The system responses with and without the control are calculated and compared. The feasibility and potential of applying ANNs to seismic active control is asserted by the promising results obtained from the numerical examples studied.
Date: December 31, 1995
Creator: Tang, Yu
Partner: UNT Libraries Government Documents Department

Soil structure interaction analysis of buried tank subjected to vertical excitations

Description: Underground High Level Waste Storage Tanks are subjected to strigent seismic requirements At some DOE sites, many existing waste storage tanks are of the double-shell tank design. In this configuration, the concrete outer structure acts as the vault and provides secondary confinement for the primary steel waste storage tank. To ensure the safety of the design and a good understanding of the seismic response of the concrete confinement structure, seismic analysis, including the effects of Soil-Structure Interaction (SSI), is generally performed with special purpose SSI computer analysis programs. Generally, the seismic SSI response due to vertical excitation is considered to be secondary to those of the horizontal excitation. In this paper, a detailed evaluation of the SSI response due to vertical excitation is presented and is shown to merit equal consideration relative to the horizontal excitation. The geometry and relative dimensions (i.e. flexibility) of the structure can have significant influence on the vertical seismic SSI response in local region(s) of the concrete structure.
Date: September 1, 1995
Creator: Wong, C.K.; Stine, M.; Wagenblast, G. & Farnworth, S.
Partner: UNT Libraries Government Documents Department

Y-12 site-specific earthquake response analysis and soil liquefaction assessment

Description: A site-specific earthquake response analysis and soil liquefaction assessment were performed for the Oak Ridge Y-12 Plant. The main purpose of these studies was to use the results of the analyses for evaluating the safety of the performance category -1, -2, and -3 facilities against the natural phenomena seismic hazards. Earthquake response was determined for seven (7), one dimensional soil columns (Fig. 12) using two horizontal components of the PC-3 design basis 2000-year seismic event. The computer program SHAKE 91 (Ref. 7) was used to calculate the absolute response accelerations on top of ground (soil/weathered shale) and rock outcrop. The SHAKE program has been validated for horizontal response calculations at periods less than 2.0 second at several sites and consequently is widely accepted in the geotechnical earthquake engineering area for site response analysis.
Date: September 29, 1995
Creator: Ahmed, S.B.; Hunt, R.J. & Manrod, W.E. III
Partner: UNT Libraries Government Documents Department

Seismic margins assessment of the plutonium processing facility Los Alamos National Laboratory

Description: Results of the recently completed seismic evaluation at the Los Alamos National Laboratory site indicate a need to consider seismic loads greater than design basis for many structures systems and components (SSCs). DOE Order 5480.28 requires that existing SSCs be evaluated to determine their ability to withstand the effects of earthquakes when changes in the understanding of this hazard results in greater loads. In preparation for the implementation of DOE Order 5480.28 and to support the update of the facility Safety Analysis Report, a seismic margin assessment of SSCs necessary for a monitored passive safe shutdown of the Plutonium Processing Facility (PF-4) was performed. The seismic margin methodology is given in EPRI NP-6041-SL, ``A Methodology for Assessment of Nuclear Power Plant Seismic Margin (Revision 1)``. In this methodology, high confidence of low probability of failure (HCLPF) capacities for SSCs are estimated in a deterministic manner. For comparison to the performance goals given in DOE Order 5480.28, the results of the seismic margins assessment were used to estimate the annual probability of failure for the evaluated SSCs. In general, the results show that the capacity for the SSCs comprising PF-4 is high. This is to be expected for a newer facility as PF-4 was designed in the early 1970`s. The methodology and results of this study are presented in this paper.
Date: December 1, 1995
Creator: Goen, L.K. & Salmon, M.W.
Partner: UNT Libraries Government Documents Department

Site specific seismic hazard analysis at the DOE Kansas City Plant

Description: A site specific seismic hazard analysis is being conducted for the Kansas City Plant to support an on-going structural evaluation of existing buildings. This project is part of the overall review of facilities being conducted by DOE. The seismic hazard was probabilistically defined at the theoretical rock outcrop by Lawrence Livermore National Laboratory. The USArmy Engineer Waterways Experiment Station conducted a subsurface site investigation to characterize in situ S-wave velocities and other subsurface physical properties related to the geology in the vicinity of the Main Manufacturing Building (MMB) at the Bannister Federal Complex. The test program consisted of crosshole S-wave, seismic cone penetrometer testing,and laboratory soil analyses. The information acquired from this investigation was used in a site response analysis by City College of New York to determine the earthquake motion at grade. Ground response spectra appropriate for design and evaluation of Performance Category 1 and 2 structures, systems, and components were recommended. Effects of seismic loadings on the buildings will be used to aid in designing any structural modifications.
Date: October 1, 1995
Creator: Lynch, D.T.; Drury, M.A.; Meis, R.C.; Bieniawski, A.; Savy, J.B.; Llopis, J.L. et al.
Partner: UNT Libraries Government Documents Department


Description: As part of a verification test program for seismic analysis codes for NPP structures, the Nuclear Power Engineering Corporation (NUPEC) of Japan has conducted a series of field model test programs to ensure the adequacy of methodologies employed for seismic analyses of NPP structures. A collaborative program between the United States and Japan was developed to study seismic issues related to NPP applications. The US Nuclear Regulatory Commission (NRC) and its contractor, Brookhaven National Laboratory (BNL), are participating in this program to apply common analysis procedures to predict both free field and soil-structure Interaction (SSI) responses to recorded earthquake events, including embedment and dynamic cross interaction (DCI) effects. This paper describes the BNL effort to predict seismic responses of the large-scale realistic model structures for reactor and turbine buildings at the NUPEC test facility in northern Japan. The NUPEC test program has collected a large amount of recorded earthquake response data (both free-field and in-structure) from these test model structures. The BNL free-field analyses were performed with the CARES program while the SSI analyses were preformed using the SASS12000 computer code. The BNL analysis includes both embedded and excavated conditions, as well as the DCI effect, The BNL analysis results and their comparisons to the NUPEC recorded responses are presented in the paper.
Date: August 17, 2003
Partner: UNT Libraries Government Documents Department


Description: A study was performed by Brookhaven National Laboratory (BNL) under the sponsorship of the U. S. Nuclear Regulatory Commission (USNRC), to determine the applicability of established soil-structure interaction analysis methods and computer programs to deeply embedded and/or buried (DEB) nuclear power plant (NPP) structures. This paper provides an overview of the BNL study including a description and discussions of analyses performed to assess relative performance of various SSI analysis methods typically applied to NPP structures, as well as the importance of interface modeling for DEB structures. There are four main elements contained in the BNL study: (1) Review and evaluation of existing seismic design practice, (2) Assessment of simplified vs. detailed methods for SSI in-structure response spectrum analysis of DEB structures, (3) Assessment of methods for computing seismic induced earth pressures on DEB structures, and (4) Development of the criteria for benchmark problems which could be used for validating computer programs for computing seismic responses of DEB NPP structures. The BNL study concluded that the equivalent linear SSI methods, including both simplified and detailed approaches, can be extended to DEB structures and produce acceptable SSI response calculations, provided that the SSI response induced by the ground motion is very much within the linear regime or the non-linear effect is not anticipated to control the SSI response parameters. The BNL study also revealed that the response calculation is sensitive to the modeling assumptions made for the soil/structure interface and application of a particular material model for the soil.
Date: April 1, 2007
Partner: UNT Libraries Government Documents Department


Description: Seismic analysis is of great importance in the evaluation of nuclear systems due to the heavy influence such loading has on their designs. Current Department of Energy seismic analysis techniques for a nuclear safety-related piping system typically involve application of a single conservative seismic input applied to the entire system [1]. A significant portion of this conservatism comes from the need to address the overlapping uncertainties in the seismic input and in the building response that transmits that input motion to the piping system. The approach presented in this paper addresses these two sources of uncertainty through the application of a suite of 32 input motions whose collective performance addresses the total uncertainty while each individual motion represents a single variation of it. It represents an extension of the soil-structure interaction analysis methodology of SEI/ASCE 43-05 [2] from the structure to individual piping components. Because this approach is computationally intensive, automation and other measures have been developed to make such an analysis efficient. These measures are detailed in this paper.
Date: July 1, 2009
Creator: Crawford, Anthony L.; Robert E. Spears, Ph.D. & Russell, Mark J.
Partner: UNT Libraries Government Documents Department

The Second International Piping Integrity Research Group (IPIRG-2) program. Final report, October 1991--April 1996

Description: The IPIRG-2 program was an international group program managed by the US NRC and funded by organizations from 15 nations. The emphasis of the IPIRG-2 program was the development of data to verify fracture analyses for cracked pipes and fittings subjected to dynamic/cyclic load histories typical of seismic events. The scope included: (1) the study of more complex dynamic/cyclic load histories, i.e., multi-frequency, variable amplitude, simulated seismic excitations, than those considered in the IPIRG-1 program, (2) crack sizes more typical of those considered in Leak-Before-Break (LBB) and in-service flaw evaluations, (3) through-wall-cracked pipe experiments which can be used to validate LBB-type fracture analyses, (4) cracks in and around pipe fittings, such as elbows, and (5) laboratory specimen and separate effect pipe experiments to provide better insight into the effects of dynamic and cyclic load histories. Also undertaken were an uncertainty analysis to identify the issues most important for LBB or in-service flaw evaluations, updating computer codes and databases, the development and conduct of a series of round-robin analyses, and analyst`s group meetings to provide a forum for nuclear piping experts from around the world to exchange information on the subject of pipe fracture technology. 17 refs., 104 figs., 41 tabs.
Date: March 1, 1997
Creator: Hopper, A.; Wilowski, G.; Scott, P. & Olson, R.
Partner: UNT Libraries Government Documents Department

Seismic vulnerability study Los Alamos Meson Physics Facility (LAMPF)

Description: The Los Alamos Meson Physics Facility (LAMPF), located at TA-53 of Los Alamos National Laboratory (LANL), features an 800 MeV proton accelerator used for nuclear physics and materials science research. As part of the implementation of DOE Order 5480.25 and in preparation for DOE Order 5480.28, a seismic vulnerability study of the structures, systems, and components (SSCs) supporting the beam line from the accelerator building through to the ends of die various beam stops at LAMPF has been performed. The study was accomplished using the SQUG GIP methodology to assess the capability of the various SSCs to resist an evaluation basis earthquake. The evaluation basis earthquake was selected from site specific seismic hazard studies. The goals for the study were as follows: (1) identify SSCs which are vulnerable to seismic loads; and (2) ensure that those SSCs screened during die evaluation met the performance goals required for DOE Order 5480.28. The first goal was obtained by applying the SQUG GIP methodology to those SSCS represented in the experience data base. For those SSCs not represented in the data base, information was gathered and a significant amount of engineering judgment applied to determine whether to screen the SSC or to classify it as an outlier. To assure the performance goals required by DOE Order 5480.28 are met, modifications to the SQUG GIP methodology proposed by Salmon and Kennedy were used. The results of this study ire presented in this paper.
Date: December 1, 1995
Creator: Salmon, M. & Goen, L.K.
Partner: UNT Libraries Government Documents Department

Evaluation of the potential for surface faulting at TA-63. Final report

Description: This report describes an investigation of the potential for surface faulting at the proposed sites for the Radioactive Liquid Waste Treatment Facility (RL)WF) and the Hazardous Waste Treatment Facility at TA-63 and TA-52 (hereafter TA-63), Los Alamos National Laboratory (LANL). This study was performed by Woodward-Clyde Federal Services (WCFS) at the request of the LANL. The projections of both the Guaje Mountain and Rendija Canyon faults are mapped in the vicinity of TA-63. Based on results obtained in the ongoing Seismic Hazard Evaluation Program of the LANL, displacement may have occurred on both the Guaje Mountain and Rendija Canyon faults in the past 11,000 years (Holocene time). Thus, in accordance with US Department of Energy (DOE) Orders and Standards for seismic hazards evaluations and the US Environmental Protection Agency (EPA) Resource Conservation and Recovery Act (RCRA) Regulations for seismic standard requirements, a geologic study of the proposed TA-63 site was conducted.
Date: January 1, 1995
Creator: Kolbe, T.; Sawyer, J.; Springer, J.; Olig, S.; Hemphill-Haley, M.; Wong, I. et al.
Partner: UNT Libraries Government Documents Department

Dynamic response of cantilever retaining walls

Description: A critical evaluation is made of the response to horizontal ground shaking of flexible cantilever retaining walls that are elastically constrained against rotation at their base. The retained medium is idealized as a uniform, linear, viscoelastic stratum of constant thickness and semi-infinite extent in the horizontal direction. The parameters varied include the flexibilities of the wall and its base, the properties of the retained medium, and the characteristics of the ground motion. In addition to long-period, effectively static excitations, both harmonic base motions and an actual earthquake record are considered. The response quantities examined include the displacements of the wall relative to the moving base, the wall pressures, and the associated shears and bending moments. The method of analysis employed is described only briefly, emphasis being placed on the presentation and interpretation of the comprehensive numerical solutions. It is shown that, for realistic wall flexibilities, the maximum wall forces are significantly lower than those obtained for fixed-based rigid walls and potentially of the same order of magnitude as those computed by the Mononobe-Okabe method.
Date: October 1, 1996
Creator: Veletsos, A.S.; Younan, A.H. & Bandyopadhyay, K.
Partner: UNT Libraries Government Documents Department

Seismic induced architectural damage to masonry structures at Mercury, Nevada

Description: Selected masonry structures in Mercury, Nevada, were inspected for cracking before and after certain nuclear detonations and during periods of no significant nuclear activity. Detonations gave peak particle velocities whose magnitudes approached those experienced in Mississippi during the Salmon event. Findings include evidence that peak particle velocities of 0. 1 to 0. 3 cm/sec caused more cracking than normal; however, cracks at these low levels of motion are not more severe than those occurring naturally.
Date: June 1, 1966
Creator: Wall, J. F., Jr.
Partner: UNT Libraries Government Documents Department