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Project Drum Inlet: explosive excavation in saturated sand

Description: Seasonal storms during February of 1971 completely closed the Drum Inlet navigation channel through the Outer Banks off the North Carolina coast. This channel is highly useful to commercial and sport fishing industries in the Carteret County vicinity of North Carolina, and is vital to maintenance of the ecological balance in the inland Core Sound waters. To reopen Drum Inlet, an alignment about 2.1 miles south of the original location was selected. A contract dredge excavated a channel from the inland Core Sound waterway to and part way through the Outer Banks. The final 385-ft-long section of sand separating the Core Sound from the Atlantic Ocean was excavated with large explosive charges, This report describes the explosive excavation of that portion of the channel. Twenty-two separate canisters, each containing 1 ton of aluminized ammonium-nitrate slurry blasting agent, were emplaced in two rows. All charges were detonated simultaneously at 1327 hours, 23 Decembcr 1971. The detonation successfully removed the sand barrier, forming a continuous channel over 80 ft in width. This channel subsequently washed out to a width of about 1000 ft and was used:is an access route to the Raleigh Bay fishing grounds. The Drum Inlet project demonstrated the practicality of explosive channel excavation in saturated sand under the special conditions encountered at this site. (auth)
Date: October 1, 1973
Creator: Snell, C. M. & Gillespie, R. H.
Partner: UNT Libraries Government Documents Department

Comments on TNT Equivalence

Description: The term ``TNT Equivalence`` is used throughout the explosives and related industries to compare the effects of the output of a given explosive to that of TNT. This is done for technical design reasons in scaling calculation such as for the prediction of blast waves, craters, and structural response, and is also used as a basis for government regulations controlling the shipping, handling and storage of explosive materials, as well as for the siting and design of explosive facilities. TNT equivalence is determined experimentally by several different types of tests, the most common of which include: plate dent, ballistic mortar, trauzl, sand crush, and air blast. All of these tests do not necessarily measure the same output property of the sample explosive. As examples of this, some tests depend simply upon the CJ pressure, some depend upon the PV work in the CJ zone and in the Taylor wave behind the CJ plane, some are functions of the total work which includes that from secondary combustion in the air mixing region of the fireball and are acutely effected by the shape of the pressure-time profile of the wave. Some of the tests incorporate systematic errors which are not readily apparent, and which have a profound effect upon skewing the resultant data. Further, some of the tests produce different TNT Equivalents for the same explosive which are a function of the conditions at which the test is run. This paper describes the various tests used, discusses the results of each test and makes detailed commentary on what the test is actually measuring, how the results may be interpreted, and if and how these results can be predicted by first principals based calculations. Extensive data bases are referred to throughout the paper and used in examples for each point in the commentaries.
Date: July 1, 1994
Creator: Cooper, P. W.
Partner: UNT Libraries Government Documents Department

A Study of the Conservatism of Resonant Shock Test Fixtures

Description: Portions of a series of end-of-life tests are described for a Sandia National Li~boratories- designed space-based sensor that utilizes a mercury-cadmium-telluride focal plane array. Variations in background intensity are consistent with the hypothesis that seasonal variations in solar position cause changes in the pattern of shadows falling across the compartment containing the optical elements, filter-band components, and focal plane array. When the sensor compartment is most fully illuminated by the sun, background intensities are large and their standard deviations tend to be large. During the winter season, when the compartment is most fully shadowed by surrounding structure, backgrounci intensities are small and standard deviations tend to be small. Details in the surrounding structure are speculated to produce transient shadows that complicate background intensifies as a function of time or of sensor position in orbit. KEYwoRDs Noise measurements, background intensity, focal plane array, mercury-cadmium-telluride.
Date: December 3, 1998
Creator: Cap, J.S.
Partner: UNT Libraries Government Documents Department


Description: The Arizona Source Phenomenology Experiments (SPE) have resulted in an important dataset for the nuclear monitoring community. The 19 dedicated single-fired explosions and multiple delay-fired mining explosions were recorded by one of the most densely instrumented accelerometer and seismometer arrays ever fielded, and the data have already proven useful in quantifying confinement and excitation effects for the sources. It is very interesting to note that we have observed differences in the phenomenology of these two series of explosions resulting from the differences between the relatively slow (limestone) and fast (granodiorite) media. We observed differences at the two SPE sites in the way the rock failed during the explosions, how the S-waves were generated, and the amplitude behavior as a function of confinement. Our consortium's goal is to use the synergy of the multiple datasets collected during this experiment to unravel the phenomenological differences between the two emplacement media. The data suggest that the main difference between single-fired chemical and delay-fired mining explosion seismograms at regional distances is the increased surface wave energy for the latter source type. The effect of the delay-firing is to decrease the high-frequency P-wave amplitudes while increasing the surface wave energy because of the longer source duration and spall components. The results suggest that the single-fired explosions are surrogates for nuclear explosions in higher frequency bands (e.g., 6-8 Hz Pg/Lg discriminants). We have shown that the SPE shots, together with the mining explosions, are efficient sources of S-wave energy, and our next research stage is to postulate the possible sources contributing to the shear-wave energy.
Date: September 30, 2005
Creator: Bonner, Jessie L.; Stump, Brian; Leidig, Mark; Hooper, Heather; Yang, Xiaoning (David); Zhou, Rongmao et al.
Partner: UNT Libraries Government Documents Department

Shock initiation study of PBX-9404

Description: Pressure-field histories during the sustained and short-duration shock initiation of PBX-9404 explosive (plastic-bonded HMX) have been determined with embedded Manganin gauges. Numerical integration of the conservation relations and an assumed equation of state are used to obtain the decomposition histories during the initiation process. In both cases, this process is effected by reaction originating near the impact face producing pressure pulses that overtake the shock front and enhance its strength, leading to an abrupt transition to detonation. Correlation of reaction rates to state variables suggest an Arrhenius rate form, modified to include a dependence on shock strength and an induction time. This rate is used in computer simulations of several other initiation experiments on PBX-9404.
Date: January 1, 1978
Creator: Wackerle, J.; Rabie, R.L.; Ginsberg, M.J. & Anderson, A.B.
Partner: UNT Libraries Government Documents Department

Recording experiment on Rainier Mesa in conjunction with a reflection survey

Description: The chemical explosion of the NPE was recorded on the surface of Rainier Mesa along the same line which had previously been the site of a high resolution reflection survey. Six three-component accelerometer stations where distributed along the 550 meter line, which was offset about 600 meters from the epicenter of the explosion. The bandwidth of the acceleration data extends to 100 Hz. Even though the separations of the stations was only about 100 meters, the waveforms and the amplitudes exhibited considerable variability, especially for the transverse component of motion. The maximum accelerations ranged between 0.27 g and 1.46 g, with the maximums of the average traces being 0.57 g on the radial component, 0.28 on the transverse component, and 0.50 g on the vertical component. Using the results of the reflection survey to help constrain the velocity model, the acceleration data were inverted to obtain a preliminary estimate of the seismic moment tensor of the NPE. This result is a strong diagnostic for the NPE being an explosion, showing a somewhat asymmetric extensional source with very small shear components. When interpreted in terms of a spectral model and scaling relationships, the isotropic moment tensor indicates a yield of 1.4 kt, an elastic radius of 116 meters and a cavity radius of 15.5 meters. This interpretation includes a source time function which contains appreciable overshoot, and, if shown to be reliable, this feature of the explosion could have a significant effect upon the analyses of other types of seismic data.
Date: June 1, 1994
Creator: Johnson, L. R.
Partner: UNT Libraries Government Documents Department

Final report for confinement vessel analysis. Task 3, Analysis of confinement vessel doors

Description: The confinement vessel has five closure doors of two different sizes. The vessel must withstand an initial dynamic load and a quasi-static internal pressure with no leakage of gases through the port seals. Task 3 of the Confinement Vessel Analysis Program was to assess the doors for safety. Of primary concern is the integrity of the seal. This encompasses the structural integrity of the door and nozzle as separate structural elements and the relative motion between the door and nozzle which could cause leakage of gases around the seals. In addition, the authors would like to obtain a better understanding of the effect of the bolt preload, especially as it affects the dynamic response of the structure. The authors explain the objectives of the task in Section 1, describe the models used for the analyses in Section 2, and give results in Section 3. They list conclusions and recommendations in Section 4.
Date: December 31, 1993
Creator: Lewis, B. B.
Partner: UNT Libraries Government Documents Department

Shock initiation studies of low density HMX using electromagnetic particle velocity and PVDF stress gauges

Description: Magnetic particle velocity and PVDF stress rate gauges have been used to measure the shock response of low density octotetramethylene tetranitramine (HMX) (1.24 &/cm{sup 3}). In experiments done at LANL, magnetic particle velocity gauges were located on both sides of the explosive. In nearly identical experiments done at SNL, PVDF stress rate gauges were located at the same positions so both particle velocity and stress histories were obtained for a particular experimental condition. Unreacted Hugoniot data were obtained and an EOS was developed by combining methods used by Hayes, Sheffield and Mitchell (for describing the Hugoniot of HNS at various densities) with Hermann`s P-{alpha} model. Using this technique, it is only necessary to know some thermodynamic constants or the Hugoniot of the initially solid material and the porous material sound speed to obtain accurate unreacted Hugoniots for the porous explosive. Loading and reaction paths were established in the stress-particle velocity plane for some experimental conditions. This information was used to determine a global reaction rate of {approx} 0.13 {mu}s{sup {minus}1} for porous HMX shocked to 0.8 GPa. At low input stresses the transmitted wave profiles had long rise times (up to 1 {mu}s) due to the compaction processes.
Date: September 1, 1993
Creator: Sheffield, S. A.; Gustavsen, R. L.; Alcon, R. R.; Graham, R. A. & Anderson, M. U.
Partner: UNT Libraries Government Documents Department

Blast-wave characteristics near Site 300

Description: The blast-wave overpressures propagating in the atmosphere near the Lawrence Livermore National Laboratory (LLNL) Site 300 have been measured at selected locations to determine whether the Site 300 blast operations will be hindered by the proposed construction of a residential development adjacent to its border.We tested high-explosives (HE) weights ranging from 14 to 545 lb under various weather conditions. Although more tests should be conducted before a definitive statement can be made on the blast propagation near Site 300, we offer the following preliminary interpretation of the results obtained to date. The readings at the closest locations show that the blast-wave overpressures exceed the 126-decibel (dB) level established by LLNL at about 250 lb of HE detonation. The weather conditions do not materially affect the pressure levels at these locations. Insufficient test data exist along the Corral Hollow Road perimeter, making it difficult to reasonably predict HE blast effects along the southern border. Therefore, we recommend that additional measurements be made along this and other boundaries in future tests, to provide more comprehensive data to help determine the blast-wave propagation characteristics in the proposed development areas. Blast-wave focusing may occur in the proposed residential development area under certain weather conditions. We recommend that this possibility should be addressed for its potentially adverse impact on the proposed residential area. Because the testing ground controlled by Physics International, Inc. (PI) is adjacent to Site 300, it is important to be aware of PI`s detonation activities. Peak overpressure measurements near PI`s Corral Hollow Road entrance reveal that PI shots over 25 lb HE have exceeded 126 dB, the limit established by LLNL for safe operations.
Date: August 1, 1993
Creator: Kang, Sang-Wook & Kleiber, J. C. Jr.
Partner: UNT Libraries Government Documents Department

New technique for determining the shock initiation sensitivity of explosives

Description: A new technique for determining the shock initiation sensitivity of explosives is described. It involves a flyer plate impinging upon the test explosive to induce initiation of detonation. An electrically exploded foil propels the flyer plate, which is a thin disk of polyimide (Kapton) 1 mm in dia; the charging voltage applied to the capacitor discharge fireset is used to preselect the desired velocity of the flyer plate. Its impact on the explosive introduces a rectangular pressure plus, P, whose amplitude depends on the velocity of the flyer at impact and the shock properties of the flyer and the explosive. The duration of the pulse, tau, depends upon flyer thickness. The test objective is to establish the critical pressure at a given duration which results in a 50 percent probability of detonating the explosive. The data, presented in a log P-log tau plot, generate a demarcation line between detonation and nondetonation regions. In the experiments the impact pressure was in the range of 1 to 10 GPa and the duration from 0.039 to 0.070 ..mu..s. Pentaery-thritol tetranitrate (PETN) and three forms of hexanitrostilbene (HNS) were evaluated. For both materials and variation of the threshold stimulus with initial compaction density was measured. Since a single flyer thickness was used in all but one of the experiments, the data for each explosive give only a single value (P, tau) on the demarcation line which separates detonation from nondetonation. Additional tests with other flyer thicknesses are needed to define this line over a broad range of tau. This new technique employs conventional laboratory equipment and a simple, inexpensive test device. The initiation stimulus may be expressed in a clearly defined form which is directly applicable to safety or performance computations.
Date: January 1, 1977
Creator: Schwarz, A. C.
Partner: UNT Libraries Government Documents Department

Explosive performance measurements on large, multiple-hole arrays and large masses of conventional explosive

Description: The COntinuous Reflectometry for Radius vs. Time EXperiment (CORRTEX) system was developed by the Los Alamos National Laboratory for determining the energy released in a nuclear explosion by measuring the position of its shock front as a function of time. The CORRTEX system, fielding techniques, and the methods and software for data reduction and analysis were developed over a 15 year period with hundreds of measurements made on nuclear tests and high explosive experiments. CORRTEX is a compact, portable, fast-sampling, microprocessor-controlled system, based on time domain reflectometry, requiring only a 24 volt power source and a sensing element. Only the sensing element (a length of 50 ohm coaxial cable) is expended during the detonation. In 1979, the CORRTEX system was shown to be ideally suited for chemical explosive performance measurements. Its utility for diagnosing chemical explosives was further demonstrated with successful measurements on large multiple-hole chemical shots in rock quarries and strip mines. Accurate timing of the detonation of sequenced or ripple fired arrays, as well as data characterizing the initiation, explosive performance and detonation anomalies are obtained. This information can serve as the basis for empirical or modeled improvements to blasting operations. A summary of the special CORRTEX features and well developed analysis techniques together with the experiment designs, data, and conclusions regarding the measurements and explosive performance from several array detonations and the Chemical Kiloton Experiment, 2.9 million pounds of an ammonium nitrate-fuel oil (ANFO) and emulsion blend conducted on the Nevada Test Site in 1993, are presented.
Date: November 1, 1994
Creator: McKown, T. O.; Eilers, D. D. & Williams, P. E.
Partner: UNT Libraries Government Documents Department

Preliminary evaluation of non-hazardous explosives for security training and testing (NESTT)

Description: A series of materials has been prepared that have authentic properties of explosives but are non-hazardous. These NESTT materials are prepared by coating a few micron layer of an explosive on a non-reactive substrate. This produces a formulation with an authentic vapor signature. Authentic x-ray and oxygen/nitrogen density signatures can also be obtained through the appropriate choice of substrate. Sensitivity tests on the materials made to date show that they are non-hazardous. One such material is now in use for canine training at the Lawrence Livermore National Laboratory.
Date: September 1, 1993
Creator: Moody, G. L.; Pruneda, C. O.; Simpson, R. L.; Kury, J. W. & Dumais, D. A.
Partner: UNT Libraries Government Documents Department

Unsteady detonations driven by first-order phase transformations

Description: Reactive waves supported by the energy released during a phase transformation are examined as elementary detonations. It is found that a class of eigenvalue detonations exist containing the well known Chapman-Jouguet solution as a particular case. In general the set of eigenvalue detonations are unsteady in any single inertial reference frame.
Date: January 1, 1978
Creator: Rabie, R.L. & Fickett, W.
Partner: UNT Libraries Government Documents Department

Mixing in explosions

Description: Explosions always contain embedded turbulent mixing regions, for example: boundary layers, shear layers, wall jets, and unstable interfaces. Described here is one particular example of the latter, namely, the turbulent mixing occurring in the fireball of an HE-driven blast wave. The evolution of the turbulent mixing was studied via two-dimensional numerical simulations of the convective mixing processes on an adaptive mesh. Vorticity was generated on the fireball interface by baroclinic effects. The interface was unstable, and rapidly evolved into a turbulent mixing layer. Four phases of mixing were observed: (1) a strong blast wave phase; (2) and implosion phase; (3) a reshocking phase; and (4) an asymptotic mixing phase. The flowfield was azimuthally averaged to evaluate the mean and r.m.s. fluctuation profiles across the mixing layer. The vorticity decayed due to a cascade process. This caused the corresponding enstrophy parameter to increase linearly with time -- in agreement with homogeneous turbulence calculations of G.K. Batchelor.
Date: December 1, 1993
Creator: Kuhl, A. L.
Partner: UNT Libraries Government Documents Department

Pressing procedure for PBX 9501. Period covered: January--March 1976. Normal process development endeavor No. 105

Description: PBX 9501 can be pressed to yield a minimum density of 1.830 Mg/m/sup 3/. The compaction cycle consists of two 140 MPa pressure applications, interrupted by a one-minute relaxation period at ambient pressure. Preheat temperature and time-at-temperature are not critical factors.
Date: January 1, 1976
Creator: Harrell, J. D.
Partner: UNT Libraries Government Documents Department

ECX and PEX rheology. Progress report, October--December 1975

Description: The objectives of this project are: (1) to evaluate the capillary rheometer as a device to qualitatively measure the extrusion properties of extrusion cast and paste explosives; (2) to study and determine means to distinguish and characterize the rheological properties of different lots of ECX and PEX; and (3) to apply results from (1) and (2) to production loading operations involving ECX and PEX. The second objective (to study and determine means to distinguish and characterize rheological properties) of this project has been accomplished. Testing procedures were finalized, and general knowledge of the rheometer itself was gained. Three batches of 85/15 (wt. percent) RDX/Sylgard were tested in the Instron Capillary Rheometer. Each lot was statistically distinguishable from the other two lots. One lot exhibited a significantly lower apparent viscosity than the other two lots, which were statistically different from each other, but which were in fairly close agreement.
Date: January 1, 1975
Creator: West, G. T.
Partner: UNT Libraries Government Documents Department

LX-13 processing. Progress report, October--December 1975. [Effect of precipitation parameters on extrudability and detonability]

Description: Results were obtained from five LX-13 batches formulated from PETN precipitated previously by the continuous method. Extrudability results indicate that a reduced temperature improves extrudability. Detonability was improved over previous continuous batches. Three additional batches of PETN have been precipitated at reduced temperatures to evaluate the effect of temperature on extrudability and detonability.
Date: January 1, 1975
Creator: Adams, J. C.; Stallings, T. L. & Osborn, A. G.
Partner: UNT Libraries Government Documents Department

Light production at an explosive/air interface. Period covered: October--December 1976

Description: Detonation front arrival time measurements are compared for an optoelectronic and an antenna technique. Fiber optics and photodiodes are used for the optoelectronic method while the antenna technique depends on radiated signals at an explosive/air interface. Analysis indicates that signals measured by the respective techniques are not caused by the same physical mechanism; thus, even though the results are not directly comparable the signals should be self-consistent for a given technique. The optical signals were found to have greater jitter in time and larger variation in magnitude than those signals obtained by the antenna technique.
Date: January 1, 1976
Creator: Canada, C. E.
Partner: UNT Libraries Government Documents Department