1,044 Matching Results

Search Results

Advanced search parameters have been applied.

Seismic evaluation of lead caves using no-tension discrete model with interface elements

Description: This paper investigates quasi-static behavior of lead cave walls radiation shields made by stacking lead bricks. The bricks have high stiffness, whereas the joints are weak and incapable of supporting tension. Global behavior of this kind of wall is strongly influenced by size friction coefficient of the brick elements. The general finite element code ANSYS was used for the analysis of the lead caves. A series of 2-D models that spanned the range of height-to-width aspect ratios of the cave wall were constructed. Two types of contact elements were incorporated in the model. The point-to-point contact element was used to represent contact in the horizontal direction. This element permits either compression in the direction normal to the surfaces or opening of a gap. The point-to-surface contact element was chosen to represent contact in the vertical direction. This element allows sliding in addition to the compression or gap formation normal to the surface. A series of static analyses were performed for each model. A l-g. vertical acceleration representing gravity was applied. The lateral acceleration was increased until the solution would not converge. This acceleration is defined as the critical lateral acceleration. This was achieved with a set of load steps with increasing lateral load. The critical acceleration was found to depend on the wall aspect ratio. For a wall with an aspect ratio up to three, the maximum acceleration is above the required 0.1 g. The wall failure mechanisms were also identified based on the numerical results. The two failure modes are the rotation and loss of interlocking among the blocks or silding of upper layers of the wall.
Date: July 1, 1995
Creator: Khaleel, M.A.; Deibler, J.E. & Koontz, D.A.
Partner: UNT Libraries Government Documents Department

Independent review of Oak Ridge HCTW test program and development of seismic evaluation criteria

Description: Many of the existing buildings at the Oak Ridge Y-12 Plant are steel frame construction with unreinforced hollow clay tile infill walls (HCTW). The HCTW infill provides some lateral seismic resistance to the design/evaluation basis earthquake; however acceptance criteria for this construction must be developed. The basis for the development of seismic criteria is the Oak Ridge HCTW testing and analysis program and the target performance goals of DOE 5480.28 and DOE-STD-1020-94. This report documents and independent review of the testing and analysis program and development of recommended acceptance criteria for Oak Ridge HCTW construction. The HCTW test program included ``macro`` wall in-plane and out-of-plane tests, full-scale wall in-plane and out-of-plane tests, in-situ out-of-plane test, shake table tests, and masonry component tests.
Date: May 1, 1995
Partner: UNT Libraries Government Documents Department

TRILIN: a computer analysis of the transient response of elastic structures

Description: The computer code TRILIN employs a force method that uses prismatic beam- type elements and discrete masses for the analysis of the transient response of linearly elastic, three-dimensional, frame-type structures subjected to arbitrary loading conditions. Each beam element is capable of resisting tension, bending, and torsion. A global stiffness matrix is obtained by inverting the flexibility relationships. Modal superposition is used to solve the governing equations. (auth)
Date: October 26, 1973
Creator: Miller, A.B.; Weston, A.M.; Hallquist, J.O. & Bernreuter, D.L.
Partner: UNT Libraries Government Documents Department

Quantification of seismic liquefaction risk

Description: Explicit goals of acceptable risk for natural phenomena hazards (earthquake, extreme wind, and flood) have been established by the Department of Energy (DOE) 1994. Closely associated to the earthquake risk is the issue of seismically-induced liquefaction. Because deterministic methods currently available to answer the question to whether a site is liquefiable or not are incapable of providing a clue as to the likelihood or risk of liquefaction, the application of the criteria to a given facility requires that alternative evaluation techniques be formulated. This paper describes the application to a nuclear facility of a newly developed probabilistic methodology which rigorously accounts for geotechnical and seismologic uncertainties. The results of the analyses are compared with the acceptable levels of risk presented by DOE. This comparison is used to emphasize the power of the methodology as a tool in the decision-making processes.
Date: February 29, 1996
Creator: Arango, I.; Ostadan, F.; Lewis, M. R. & Gutierrez, B. J.
Partner: UNT Libraries Government Documents Department

Application of bounding spectra to seismic design of piping based on the performance of above ground piping in power plants subjected to strong motion earthquakes

Description: This report extends the potential application of Bounding Spectra evaluation procedures, developed as part of the A-46 Unresolved Safety Issue applicable to seismic verification of in-situ electrical and mechanical equipment, to in-situ safety related piping in nuclear power plants. The report presents a summary of earthquake experience data which define the behavior of typical U.S. power plant piping subject to strong motion earthquakes. The report defines those piping system caveats which would assure the seismic adequacy of the piping systems which meet those caveats and whose seismic demand are within the bounding spectra input. Based on the observed behavior of piping in strong motion earthquakes, the report describes the capabilities of the piping system to carry seismic loads as a function of the type of connection (i.e. threaded versus welded). This report also discusses in some detail the basic causes and mechanisms for earthquake damages and failures to power plant piping systems.
Date: February 1, 1995
Creator: Stevenson, J.D.
Partner: UNT Libraries Government Documents Department

Evaluation and analysis of the performance of masonary infills during the Northridge earthquake

Description: Observations were made of the behavior of masonry infills in structural frames during the Northridge earthquake, and an analytical technique was developed for analyzing infilled frame structures. Infills near the epicenter suffered significant damage, but in several cases contributed to the seismic resistance and life safety performance. Older infill buildings in downtown Los Angeles experienced intensity of shaking similar to that expected in central/eastern United States earthquakes. The infills experienced some cracking, but otherwise complemented the lateral resistance of the weak building frames. This suggests infill frame buildings in moderate seismic zones may provide at least life safety functions without the need for expensive retrofit. A developed analytical technique was used to analyze two buildings for which the observed behavior and records from the Northridge earthquake were available. The analytical technique was based on using a piecewise linear equivalent strut for the infill. Parameters for the strut were obtained by examining the results of a wide variety of experimental infill tests. The strut method is easy to incorporate in standard linear analyses, and converges quite rapidly. The strut method was applied to two structures that had records from the Northridge earthquake. Very favorable comparisons between the analytical method and observed response were obtained. Recommendations were made concerning evaluation of the vulnerability of infills to earthquakes, and the construction of infills.
Date: February 1, 1996
Creator: Bennett, R. M.; Fischer, W. L.; Flanagan, R. D. & Tenbus, M. A.
Partner: UNT Libraries Government Documents Department

A report on the seismic capacity of the General Laboratory and Administration Building at Los Alamos National Laboratory

Description: A seismic analysis of the General Laboratory and Administration Building at Los Alamos National Laboratory is performed. The analyses are performed in detail for one portion of the building and then qualitatively extrapolated to other portions of the building. Seismic capacities are evaluated based on two sets of acceptance criteria. The first is based on Code-type criteria and is associated with a low probability of failure. This capacity is found to be in the 0.04--0.06 G ZPA range (the free field seismic motion is defined with a NUREG 0098 response spectrum). The second capacity is based on much less conservative criteria such as might be associated with a high probability of failure. This capacity is found to be about 0.15 G. Finally structural modifications are proposed that would increase the low probability of failure capacity to 0.15 G ZPA. These modifications consist of steel double angle braces or concrete shear walls placed at some of the frames in the building.
Date: January 1, 1995
Creator: Miller, C.A.; Costantino, C.J.; Zhu, Y.; Wang, Y.K.; Shteyngart, S.; Xu, J. et al.
Partner: UNT Libraries Government Documents Department

Seismic evaluation of K basin bridge cranes (HOI-320 & HOI-418) and supporting structure

Description: The Safety Class 1 100-K fuel storage basins are vulnerable to impact damage if a bridge crane were to fall during a seismic event. The pupose of this report is to address the adequacy of the K Basin bridge cranes to resist a seismic-induced fall. The approach used to demonstrate adequacy against falling, was to evaluate the crane structural components relative to requirements specified in ASME NOG-1, Rules for Construction of Overhead and Gantry Cranes. Additionally, wheel lift-off and the adequacy of the crane supporting structure, are addressed. Seismic adequacy of the mechanical hoist equipment is not addressed in this report.
Date: March 1, 1996
Creator: Winkel, B.V. & Kanjilad, S.K.
Partner: UNT Libraries Government Documents Department

Masonry infill performance during the Northridge earthquake

Description: The response of masonry infills during the 1994 Northridge, California earthquake is described in terms of three categories: (1) lowrise and midrise structures experiencing large near field seismic excitations, (2) lowrise and midrise structures experiencing moderate far field excitation, and (3) highrise structures experiencing moderate far field excitation. In general, the infills provided a positive beneficial effect on the performance of the buildings, even those experiencing large peak accelerations near the epicenter. Varying types of masonry infills, structural frames, design conditions, and construction deficiencies were observed and their performance during the earthquake indicated. A summary of observations of the performance of infills in other recent earthquakes is given. Comparison with the Northridge earthquake is made and expected response of infill structures in lower seismic regions of the central and eastern United States is discussed.
Date: March 8, 1996
Creator: Flanagan, R.D.; Bennett, R.M.; Fischer, W.L. & Adham, S.A.
Partner: UNT Libraries Government Documents Department

Walkdown procedure: Seismic adequacy review of safety class 3 & 4 commodities in 2736-Z & ZB buildings at PFP facility

Description: Seismic evaluation of existing safety class (SC) 3 and non-SC 4 commodities at the Plutonium Finishing Plant (PFP) is integrated into an area walkdown program. Field walkdowns of potential PFP seismic deficiencies associated with structural failure and falling will be performed using the DOE SQUG/EPRI methodology. Potential proximity interactions are also addressed. Objective of the walkdown is to qualify as much of the equipment as practical and to identify candidates for further evaluation.
Date: March 29, 1995
Creator: Ocoma, E.C.
Partner: UNT Libraries Government Documents Department

SUSPNDRS: a numerical simulation tool for the nonlinear transient analysis of cable support bridge structures, part 1: theoretical development

Description: The work reprint on herein was aimed at developing methodologies and tools for efficient and accurate numerical simulation of the seismic response of suspension and cable-stayed structures. A special purpose finite element program has been constructed and the underlying theory and demonstration example problems are presented. A companion report [Ref 1] discusses the application of this technology for a major suspension bridge structure.
Date: June 1997
Creator: McCallen, D. & Astaneh-Asl, A.
Partner: UNT Libraries Government Documents Department

The January 17, 1994 Northridge Earthquake: Effects on selected industrial facilities and lifelines

Description: Revision 0 of this report is being published in February 1995 to closely mark the one-year anniversary of the Northridge Earthquake. A September 1994 Draft version of the report was reviewed by DOE and NRC, and many of the review comments are incorporated into Revision 0. While this revision of the report is not entirely complete, it is being made available for comment, review, and evaluation. Since the report was written by several authors, sections of the report have slightly different styles. Several sections of Revision 0 are not complete, but are planned to be completed in Revision 1. The primary unfinished section is Section 3.3 on Electric Power Transmission. Other sections of Revision 0, such as Section 4.5.2 on the Energy Technology Engineering Center and 3.2 on Electric Power Generation, will be enhanced with further detailed information as it becomes available. In addition, further data, including processed response spectra for investigated facilities and cataloging of relay performance, will be added to Revision 1 depending upon investigation support. While Revision 0 of this report is being published by LLNL, Revision 1 is planned to be published by EPRI. The anticipated release date for Revision 1 is December 1995. Unfortunately, the one-year anniversary of the Northridge Earthquake was also marked by the devastating Hyogo-Ken Nanbu (or Hanshin-Awaji) Earthquake in Kobe, Japan. As compared to the Northridge Earthquake, there were many more deaths, collapsed structures, destroyed lifelines, and fires following the Kobe Earthquake. Lessons from the Kobe Earthquake will both reemphasize topics discussed in this report and provide further issues to be addressed when designing and retrofitting structures, systems, and components for seismic strong motion.
Date: February 1, 1995
Creator: Eli, M.W.; Sommer, S.C.; Roche, T.R. & Merz, K.L.
Partner: UNT Libraries Government Documents Department