Author: Bruce B. RedpathPublisher:
ISBN:
Category : Cratering
Languages : en
Pages : 30
Book Description
Project Pre-GONDALA III
Author: Bruce B. RedpathPublisher:
ISBN:
Category : Cratering
Languages : en
Pages : 30
Book Description
Project Pre-gondola Iii, Phase i Summary Report
Author: J.P. CressProject Pre-GONDOLA
Author: Maurice K. Kurtz (Jr.)Publisher:
ISBN:
Category : Nuclear excavation
Languages : en
Pages : 84
Book Description
Measurements of intermediate range ground motions and of structural response were made during the Pre-Gondola high explosive cratering experiments at Fort Peck, Montana. Liquid nitromethane charges (1000-lb and 20-ton), emplaced at various depths of burst, and a 140-ton row charge were detonated in the Bearpaw shale, which is a weak, wet clay-shale medium. An additional experiment to validate a charge emplacement concept designed to decouple seismic energy proved inconclusive. All seismic measurements were of particle velocity. Using an inverse power law equation to describe the attenuation of seismic amplitudes with distance, it is found that the amplitudes from the single charges decayed as approximately R( -2.4), and amplitudes from the row-charge decayed as R( -1.7). A dependence of amplitudes on depth of burst exists, and a yield scaling exponent near 0.8 appears to be appropriate. It is suggested that a variation of particle velocity with distance as R( -A)e( -kfR), where f is the signal frequency, is a more physically realistic description of attenuation than is the inverse power law. The preliminary data from the 140-ton row charge appear to fit this type of attenuation law, and indicate that A = 0.5 and k = 0.015 sec/km. An estimate is made of the near-source variation of peak seismic amplitude with frequency for the row charge, and predictions are made for possible future row-charge cratering experiments at the site.
Project Pre-Gondola III
Author: Jerome E. LatteryPublisher:
ISBN:
Category : Cratering
Languages : en
Pages : 80
Book Description
Project Pre-Gondola III
Author: J. P. CressPublisher:
ISBN:
Category : Cratering
Languages : en
Pages : 78
Book Description
Project Pre-Gondola III. Phase II. Summary Report: Connecting Row-Crater Experiment
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
Project Pre-Gondola III, Phase I, a continuation of chemical-explosive cratering experiments conducted in saturated clay-shale near Fort Peck, Montana, was designed to excavate a row crater with relatively flat side slopes. The technical programs conducted during the experiment were: (1) measurements of the apparent crater, (2) surface-motion analysis, (3) cloud-development studies, and (4) airblast measurements. (Author).
Project Pre-Gondola III Phase III: Connection of a Row Crater to a Reservoir
Author: Bruce B. RedpathPublisher:
ISBN:
Category : Cratering
Languages : en
Pages : 25
Book Description
Project Pre-GONDOLA III Phase III, the connection of a row crater to a reservoir, was executed on 6 October 1969 and was the culmination of several years of cratering experiments in saturated clay shale near Fort Peck, Montana. This experiment used a total of 70 tons of an aluminized ammonium nitrate blasting agent in a row of five charges to remove a barrier between an existing row crater and the Fort Peck Reservoir. The excavation resulting produced by the detonation had a volume of about 63,000 cubic yards. The blasting agent appears to have a cratering effectiveness approximately 1.6 times that of TNT. (Author).
Project Pre-GONDALA
Author: Dean V. PowerPublisher:
ISBN:
Category : Blast effect
Languages : en
Pages : 82
Book Description
Ground motion records from seven high explosive cratering events in northeastern Montana were analyzed for peak velocity, power spectral density, and velocity spectra. The events included four 20-ton single charges at depths of burst which varied from 42 to 57 ft, a 140-ton row charge consisting of three 20-ton charges and two 40-ton charges at optimum depths of burst, and a fully coupled charge of 0.5 tons and a decoupled charge of 0.5 tons at optimum depths of burst. It was found that at these depths and charge weights an increase in depth of burst resulted in an increase in peak velocities and power spectral densities as measured at distant points (>5 km), while no significant frequency shifts were noted. Power spectral density was found to be approximately proportional to the first power of yield. For this region it was determined that power spectral densities varied inversely as radius to the 3.55 power, and peak velocities varied inversely as radius to the 1.6 power. An increase in both velocities and power spectral densities for small decoupling factors was found to occur for a certain explosive-cavity configuration. Three analysis techniques, peak velocity, velocity spectra, and power spectral density, are compared and it is shown that power spectral density is the most consistent method when comparing records from different measuring stations.
Project Pre-GONDOLA II, Survival of Hypothetical Preemplaced Charges
Author: Charles E. JoachimPublisher:
ISBN:
Category : Blast effect
Languages : en
Pages : 40
Book Description
Project Pre-GONDALA III
Author: Jack W. ReedPublisher:
ISBN:
Category : Blast effect
Languages : en
Pages : 24
Book Description
Four microbarograph stations recorded waves at a range of approximately 130 mi from a row charge of high explosives buried near optimum cratering depth. Comparison with propagations from three airburst calibration detonations showed that a source model derived from close-in data was appropriate for distant effects predictions. This model predicted that wave amplitudes from explosives at this scaled depth would be 20% of amplitudes expected for a free air burst. All amplitudes perpendicular to a row charge are proportional to the 0.7 power of the number of charges in the row.