Download or read book Simulation Analysis of Low Frequency Ground Motions Observed from Selected Atmospheric Nuclear Explosions at the Nevada Test Site written by John R. Murphy and published by . This book was released on 1984 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes the results of a continuing investigation of the characteristics of the low frequency ground motions produced by atmospheric explosions. The studies reported here have focused on two aspects of this problem: (1) the full-scale validation of nuclear tests, and (2) the preliminary evaluation of a theoretically-based prediction methodology. With regard to the validation study, the mathematical model has been applied to the theoretical simulation of ground motion data recorded from the Nevada Test Site atmospheric nuclear explosions TUMBLER I, UPSHOT-KNOTHOLE 10 and SMALL BOY. The results of these simulations have confirmed the fact that the observed low frequency ground motions from such explosions can be accounted for by the airblast-induced, elastic surface waves. Moreover, the simulation analysis of the ground motion data recorded from the near-surface SMALL BOY explosion has confirmed the existence of an 'exclusion radius' for such events, within which incident airblast energy is not efficiently coupled into the surface wave mode of propagation due to dissipation associated with strong, nonlinear interaction effects. On the other hand, the evidence provided by the TUMBLER I and UPSHOT-KNOTHOLE 10 analyses has indicated that this exclusion radius is effectively zero for explosions with significant height of burst.
Download or read book Energy Research Abstracts written by and published by . This book was released on 1994-03 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Analysis of Low Frequency Ground Motions Induced by Near Surface and Atmospheric Explosions written by J. R. Murphy and published by . This book was released on 1982 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes the results of a preliminary analysis of the effects of variations in height of burst (HOB) on the low frequency ground motions induced by near-surface and atmospheric explosions. A mathematical model which can be used to simulate this component of the explosively generated ground motions is described and applied to the parametric investigation of the effects of HOB on a prototype 1 kt nuclear explosion detonated over a site model approximating the subsurface geology at Yucca Flat on the Nevada Test Site. These simulations indicate that although the details of the airblast loading vary considerably with HOB, the corresponding induced low frequency Rayleigh waves are essentially independent of HOB for HOB ranging from to 0 to 500m, at least for this site. The same theoretical model is also applied to the simulation of the low frequency ground motions to be expected from the proposed Pre-Direct Course HE experiment and a hypothetical surface burst test of the same yield at that site. It is shown that the surface waves predicted on the basis of the currently available subsurface model of the site are quite simple and pulse-like and also show little dependence on HOB over the range considered.
Download or read book Summary of Ground Motion Prediction Results for Nevada Test Site Underground Nuclear Explosions Related to the Yucca Mountain Project written by Marianne C. Walck and published by . This book was released on 1996 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report summarizes available data on ground motions from underground nuclear explosions recorded on and near the Nevada Test Site, with emphasis on the ground motions recorded at stations on Yucca Mountain, the site of a potential high-level radioactive waste repository. Sandia National Laboratories, through the Weapons Test Seismic Investigations project, collected and analyzed ground motion data from NTS explosions over a 14-year period, from 1977 through 1990. By combining these data with available data from earlier, larger explosions, prediction equations for several ground motion parameters have been developed for the Test Site area for underground nuclear explosion sources. Also presented are available analyses of the relationship between surface and downhole motions and spectra and relevant crustal velocity structure information for Yucca Mountain derived from the explosion data. The data and associated analyses demonstrate that ground motions at Yucca Mountain from nuclear tests have been at levels lower than would be expected from moderate to large earthquakes in the region; thus nuclear explosions, while located relatively close, would not control seismic design criteria for the potential repository.
Download or read book Summary of Ground Motion Prediction Results for Nevada Test Site Underground Nuclear Explosions Related to the Yucca Mountain Project written by and published by . This book was released on 1996 with total page 99 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report summarizes available data on ground motions from underground nuclear explosions recorded on and near the Nevada Test Site, with emphasis on the ground motions recorded at stations on Yucca Mountain, the site of a potential high-level radioactive waste repository. Sandia National Laboratories, through the Weapons Test Seismic Investigations project, collected and analyzed ground motion data from NTS explosions over a 14-year period, from 1977 through 1990. By combining these data with available data from earlier, larger explosions, prediction equations for several ground motion parameters have been developed for the Test Site area for underground nuclear explosion sources. Also presented are available analyses of the relationship between surface and downhole motions and spectra and relevant crustal velocity structure information for Yucca Mountain derived from the explosion data. The data and associated analyses demonstrate that ground motions at Yucca Mountain from nuclear tests have been at levels lower than would be expected from moderate to large earthquakes in the region; thus nuclear explosions, while located relatively close, would not control seismic design criteria for the potential repository.
Download or read book Source Effects on Surface Waves from Nevada Test Site Explosions written by and published by . This book was released on 1981 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Surface waves recorded on the Lawrence Livermore National Laboratory (LLNL) digital network have been used to study five underground nuclear explosions detonated in Yucca Valley at the Nevada Test Site. The purpose of this study is to characterize the reduced displacement potential (RDP) at low frequencies and to test secondary source models of underground explosions. The observations consist of Rayleigh- and Love-wave amplitude and phase spectra in the frequency range 0.03 to 0.16 Hz. We have found that Rayleigh-wave spectral amplitudes are modeled well by a RDP with little or no overshoot for explosions detonated in alluvium and tuff. On the basis of comparisons between observed and predicted source phase, the spall closure source proposed by Viecelli does not appear to be a significant source of Rayleigh waves that reach the far field. We tested two other secondary source models, the strike-slip, tectonic strain release model proposed by Toksoez and Kehrer and the dip-slip thrust model of Masse. The surface-wave observations do not provide sufficient information to discriminate between these models at the low F-values (0.2 to 0.8) obtained for these explosions. In the case of the strike-slip model, the principal stress axes inferred from the fault slip angle and strike angle are in good agreement with the regional tectonic stress field for all but one explosion, Nessel. The results of the Nessel explosion suggest a mechanism other than tectonic strain release.
Download or read book Extreme Ground Motion Recorded in the Near Source Region of Underground Nuclear Explosions written by and published by . This book was released on 2005 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Free-field recordings of underground nuclear explosions constitute a unique data set within the near-source region of seismic events ranging in magnitude from M3 to M6.5. The term ''free-field'' in this context refers to recordings from instruments emplaced in boreholes or tunnel walls such that the initial portions of the records ((almost equal to)0.1 to 1 second) do not contain effects resulting from reflections at the free surface. In addition to the free-field instruments deployed to record ground motions from selected underground nuclear explosions at the Nevada Test Site (NTS) and elsewhere, surface arrays were routinely deployed to record surface accelerations and velocities from underground nuclear tests conducted at NTS.
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1989 with total page 934 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Component Ground Motion at the Nevada Test Site from Pahute Mesa Underground Nuclear Explosions written by Jerald W. Long and published by . This book was released on 1992 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Plowshare written by Carl R. Gerber and published by . This book was released on 1966 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evaluation of Nevada Test Site Ground Motion and Rock Property Data to Bound Ground Motions at the Yucca Mountain Repository written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Yucca Mountain licensing will require estimation of ground motions from probabilistic seismic hazard analyses (PSHA) with annual probabilities of exceedance on the order of 10−6 to 10−7 per year or smaller, which correspond to much longer earthquake return periods than most previous PSHA studies. These long return periods for the Yucca Mountain PSHA result in estimates of ground motion that are extremely high ((almost equal to) 10 g) and that are believed to be physically unrealizable. However, there is at present no generally accepted method to bound ground motions either by showing that the physical properties of materials cannot maintain such extreme motions, or the energy release by the source for such large motions is physically impossible. The purpose of this feasibility study is to examine recorded ground motion and rock property data from nuclear explosions to determine its usefulness for studying the ground motion from extreme earthquakes. The premise is that nuclear explosions are an extreme energy density source, and that the recorded ground motion will provide useful information about the limits of ground motion from extreme earthquakes. The data were categorized by the source and rock properties, and evaluated as to what extent non-linearity in the material has affected the recordings. They also compiled existing results of non-linear dynamic modeling of the explosions carried out by LLNL and other institutions. They conducted an extensive literature review to outline current understanding of extreme ground motion. They also analyzed the data in terms of estimating maximum ground motions at Yucca Mountain.
Download or read book Plowshare written by Robert G. West and published by . This book was released on 1971 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1989 with total page 988 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cylindrical In Situ Tests at Selected Nuclear and High Explosive Test Sites written by AIR FORCE WEAPONS LAB KIRTLAND AFB N MEX. and published by . This book was released on 1977 with total page 223 pages. Available in PDF, EPUB and Kindle. Book excerpt: The development of high confidence ground shock prediction techniques using computer simulation of nuclear bursts over or in real geologic materials is essential for adequate design and evaluation of present and future hardened land based systems. In the past, the calculational technique developed and used in these studies has relied upon material constitutive models developed from laboratory tests of material samples. Crucial to the success of this theoretical ground shock prediction program is a clear verification of the ability of the soil modeling and calculational technique to accurately reproduce ground motions generated by scaled high explosive (HE) detonations in geologies of direct interest to DOD systems. Substantial discrepancies between calculated and observed ground motions have been noted. These are attributable primarily to inadequacies in the laboratory-based soil and rock material models. To overcome some of the shortcomings of the laboratory-based modeling techniques, an in situ material property test has been developed by the Air Force Weapons Laboratory (AFWL). The Cylindrical In Situ Test (CIST) technique permits measurement of the dynamic response of geological materials to a cylindrically symmetric high explosive shock input yielding data from which in situ material properties may be determined for a range of initial loading stresses. Models based on CIST data have resulted in substantially improved agreement between calculated and observed data. Data from CIST 2 conducted in 1972, CIST 10 conducted in 1974, CIST 15 conducted in 1975, and CIST 16 conducted in 1976 are included in this report. (Author).
Download or read book Near Field and Regional Modeling of Explosions at the Degelen Test Site written by and published by . This book was released on 2000 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fundamental to the ability to monitor a Comprehensive Nuclear-Test-Ban Treaty is a good understanding of the nuclear explosion source. Considerable research has been done on the nuclear explosion source over the past 30 years, with mixed success. Although empirical and numerical models of explosion sources do a fairly good job of matching observed seismic signals, a good explanation of the physical basis for the explosion source has been elusive. In particular, numerical models of explosion sources developed using laboratory measurements of rock properties fail to predict observed near field ground motion in hardrock. The basic problem is that the strength of the rock measured in the laboratory is much larger than the apparent strength of the rock as determined from the near field ground motion. Furthermore, additional investigation shows that 1) The strength of the rock is not initially low, but rather decreases dynamically as the shock wave passes; and 2) the strength of the rock is reduced to a level well below that predicted for rubbleized rock under hydrostatic dynamic friction. Maxwell Technologies and the Institute for the Dynamics of the Geospheres (IDG) are in the early stages of a research program directed towards improving the capability to predict the seismic source characteristics of underground explosions in rock. This will be accomplished by development of improved dynamic failure models, constrained by a much better data set than has been available in the past. Near field waveforms are only available from a small number of U.S. nuclear tests, and until recently none have been available from the testing program of the former Soviet Union. IDG now has near field records from at least 10 nuclear explosions at the Degelen test site that will be made available for the project. IDG will also provide near source material properties measurements for all of these events.
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1967 with total page 1048 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Simulation of Air blast induced Ground Motion Phase i written by Harry E. Auld and published by . This book was released on 1965 with total page 81 pages. Available in PDF, EPUB and Kindle. Book excerpt: An analytical and experimental program was performed to determine the most promising techniques for simulating the air-blast-induced ground motions from a largeyield nuclear weapon. Two techniques were then selected for further development. One of the selected techniques employs a detonable gas mixture and the other a primacord matrix to generate a traveling shock wave which loads the ground. The nuclear air-blast overpressure environment is described and the simulation produced by either scheme is compared with this environment. The primacord technique was then selected because it was found to be the most practical and economical. Sufficient data are presented to enable the design of simulation experiments which use either technique. (Author).
