摘要:

The following six papers are the Proceedings of the Special Session on Nuclear Excavation sponsored by the Technical Group for Nuclear Explosives Engineering at the American Nuclear Society International Meeting in Washington, DC, November 10-15, 1968.

ISSN:0550-3043    

DOI:10.13182/NT69-A28602

出版商:Taylor&Francis    

年代:1969

数据来源: Taylor

摘要:

This paper reviews the significant technical contributions to nuclear excavation of the past few years including (a) the effect of improved explosive design on radioactivity in fallout patterns, (b) the prediction of radionuclide concentrations airborne to extended times, (c) new information on seismic damage, and (d) cratering mechanics. The major past cratering experiments are discussed in terms of how their theoretical analyses have contributed to the present predictive capability of cratering mechanisms and dimensions. Seven concepts for the application of nuclear excavation are presented, and the nuclear effects associated with them are assessed.

ISSN:0550-3043    

DOI:10.13182/NT69-A28603

出版商:Taylor&Francis    

年代:1969

数据来源: Taylor

摘要:

Project Cabriolet, a nuclear detonation in hard, dry (volcanic) rock, was executed as a part of the Plowshare Program for development of nuclear excavation techniques. The primary objectives of this experiment were: (a) to obtain experimental data on crater development and size in order to verify recently developed rock-mechanics computer codes and calculational techniques; and (b) to study the distribution of the radioactivity produced by the detonation in order to enhance the understanding of how the shot environment may affect this distribution.As was observed in the Danny Boy experiment, a relatively small amount of radioactivity was released to the environment from this detonation in hard, dry rock. Less than the equivalent of fission products from 10 tons of fission were distributed in both fallout and cloud from the Cabriolet experiment. As more data are reduced, a better description of the chemical fractionation associated with this released radioactivity will be possible.

ISSN:0550-3043    

DOI:10.13182/NT69-A28604

出版商:Taylor&Francis    

年代:1969

数据来源: Taylor

摘要:

Project Buggy, the first nuclear row-excavation experiment, was an important experiment in that it confirmed the basic concepts of channel excavation derived from HE experiments at very low yields, and proved the value of theoretical cratering calculations in predicting the effects of a nuclear detonation in an untested environment. Five nuclear explosives, each with a yield of 1.1 kt, were detonated simultaneously on March 12, 1968 in a dry, complex basalt formation on Chukar Mesa, Nevada Test Site. The explosives were buried at a depth of 41.1 m (135 ft) and spaced 45.7 m (150 ft) apart.The channel excavated has an average width of 77.4 m (254 ft), a depth of 19.8 m (65 ft), and a length of 261 m (855 ft), all measured with respect to the original ground surface. These apparent dimensions are significantly smaller than those which would be predicted on the basis of Danny Boy dimensions in the Buckboard Basalt (width, 10% less; depth, 19% less). It is believed that the small crater dimensions are due largely to the geologic conditions existing at the Buggy site. Differences in the cratering characteristics of the two basalt formations were determined by cratering calculations (TENSOR Code) prior to the detonation and the depth of burst was selected on the basis of these calculations. From the spacing of 150 ft between explosives, it was concluded that relatively large spacings can produce channels in hard rock free of noticeable scalloping or severe irregularities, even when adverse geologic conditions are present.The base surge, or cloud, which is characteristic of both nuclear and high-explosives cratering detonations, was quite circular and attained a diameter of 1157 m (3800 ft) at ~40 sec. Integration of the fallout pattern out to infinity indicates an equivalent of 35 tons of fission products were deposited.

ISSN:0550-3043    

DOI:10.13182/NT69-A28605

出版商:Taylor&Francis    

年代:1969

数据来源: Taylor

摘要:

The US Army Corp of Engineers Nuclear Cratering Group (NCG) program activities include: (1) cratering calibration of various geologic media and development of techniques designed to provide a desired crater geometry with chemical high-explosive detonations; (2) joint planning of and technical participation in AEC nuclear-excavation experiments; (3) development of data on the engineering properties of nuclear craters; (4) development of civil works nuclear construction technology; (5) accomplishment of engineering studies of nuclear construction feasibility; and (6)execution of joint CE/AEC civil works nuclear-construction experiments.Four conceptual nuclear-construction applications have been identified as having a significant potential for accomplishment: (1) nuclear quarrying to produce rock fill or aggregate; (2) nuclear ejecta dam construction; (3) nuclear harbor construction; and (4) nuclear canal excavation. The nuclear quarry has been identified as the most direct application of present technology. A site is currently being sought for a nuclear quarry experiment.

ISSN:0550-3043    

DOI:10.13182/NT69-A28606

出版商:Taylor&Francis    

年代:1969

数据来源: Taylor

摘要:

Ten years of cratering research at Sandia Laboratory are reviewed and related, along with the work of others, to the development of explosive excavation technology.Single-charge experiments gave empirical relationships between crater dimensions and energy release, burial depth and medium. Energy release spanned the greatest range in desert alluvium, from 250 to 1 000 000 lb of explosive. Dimension depth-of-burst curves have been established for two kinds of alluvium, for dry-lake playa, for tuff, and for basalt rock. Dimension depth-of-burst curves and relations between crater dimensions and energy release also were established for continuous line charges in drylake Playa.Experiments with row charges provided basic information for optimizing row-charge detonations in level terrain. Investigations then were extended to terrain with a single elevation change and later to terrain with more typical variations. Special canal-related problems included how best to excavate through high mountain regions with small charges detonated one at a time for use when safety considerations did not permit the more efficient detonation of larger charges in rows. Excavation in two vertical stages was also examined, with the finding that, to be effective, a crater from the first stage must be wide enough not to unduly restrict ejection of material from the second. Using parallel rows of explosives, it was found it is more effective to detonate parallel rows one at a time rather than to detonate two or three parallel rows simultaneously.The possible use of explosives for removing overburden for ore bodies was examined using, in addition to parallel rows, four and five charge square arrays. Using optimum combinations of spacing and burial depth, these arrays removed three times more overburden than a single charge of comparable energy at the same depth.

ISSN:0550-3043    

DOI:10.13182/NT69-A28607

出版商:Taylor&Francis    

年代:1969

数据来源: Taylor

摘要:

This paper presents an up-to-date analysis of the application of nuclear excavation technology to the design of a sea-level canal connecting the Atlantic and Pacific Oceans. This analysis is based on the technical data obtained to date under the auspices of the Atlantic-Pacific Interoceanic Canal Study Commission. Consideration is given in this paper to use of nuclear methods in the construction of a sea-level canal through the Darien region of Panama (Route 17) and the Atrato-Truando region of northwest Colombia (Route 25).The site data required for a comprehensive nuclear excavation design analysis of a proposed sea-level alignment include information pertaining to site topography, geology, hydrography, hydrology, meteorology, seismic propagation characteristics, bio-environmental conditions, and medico-ecology. These data are being used, together with data pertaining to nuclear explosive characteristics, cratering characteristics of pertinent geologic media, nuclear cratering detonation effects and channel design criteria, to develop an engineering-safety-cost analysis which is the basis for the nuclear excavation design.The results of geologic investigations to date along the 46-mile Route 17 alignment indicate that ~20 miles of the alignment through the Chucunaque Valley encounters a weak saturated clay shale while the balance of the excavation would be through relatively competent rock. In view of the unfavorable long-term slope stability characteristics of these shales, techniques were developed for using nuclear explosives to produce linear craters that have initially flat slopes of the order of 7 to 9°. Experiments indicate that nuclear excavation using a two-pass, triple-row array detonation system may offer a solution to this problem.A preliminary analysis of the topography and geology along the Route 25 sea-level canal alignment through northwest Colombia indicates that conventional excavation techniques, primarily hydraulic dredging, would be the most reasonable method of excavating ~78 miles of the 100-mile alignment. The remaining 23 miles of the alignment, through the Continental Divide, would be excavated using nuclear explosives.Studies in progress pertain to the safety aspects of using nuclear methods to construct a transisthmian sea-level canal, including consideration of seismic propagation, airblast acoustical wave phenomena, and radioactivity release. The results of such studies to date indicate that the potentially damaging effect on buildings from ground motions resulting from seismic propagations from the nuclear detonations will be the major factor in determining the maximum aggregate yield that can be detonated at any one time along the selected alignment.

ISSN:0550-3043    

DOI:10.13182/NT69-A28608

出版商:Taylor&Francis    

年代:1969

数据来源: Taylor