%A"Vortman, L J [Sandia Laboratories, Albuquerque, NM (United States)]" %D1970 %I; American Nuclear Society, Hindsdale, IL (United States); United States Atomic Energy Commission (United States) %2 %J[] %K42 ENGINEERING, BLAST EFFECTS, CHEMICAL EXPLOSIONS, IMPACT SHOCK, PRESSURE MEASUREMENT, SHOCK WAVES, THEORETICAL DATA, TNT, UNDERGROUND EXPLOSIONS %PMedium: ED; Size: page(s) 1508-1543 %TClose-in airblast from underground explosions %XAir overpressures as a function of time have been measured from surface zero to about 170 ft/lb{sup 1/3} along the ground from nuclear and chemical explosions. Charge depths varied from the surface to depths below which explosion gases are contained. A ground-shock-induced air pressure pulse is clearly distinguishable from the pulse caused by venting gases. Measured peak overpressures show reasonable agreement with the theoretical treatment by Monta. In a given medium the suppression of blast with explosion burial depth is a function of the relative distance at which the blast is observed. Rates of suppression of peak overpressure with charge burial are different for the two pulses. Rates are determined for each pulse over the range of distances at which measurements have been made of air overpressure from chemical explosions in several media. Nuclear data are available from too few shots for similar dependence on burial depth and distance to be developed, but it is clear that the gas venting peak overpressure from nuclear explosions is much more dependent on medium than that from chemical explosions. For above-ground explosions, experiment has shown that airblast from a I-kiloton nuclear explosion is equal to that from a 0.5-kiloton TNT explosion. Data on ground-shock-induced airblast is now sufficient to show that a similar relationship may exist for buried explosions. Because of medium dependence of the gas venting pulse from nuclear explosions, data from additional nuclear events will be required before a chemical/nuclear airblast equivalence can be determined for the gas-venting pulse. (author) %0Conference %NCONF-700101(vol.2); INIS-XA-N-229;TRN: XA04N0923075319 %1 %CIAEA %Rhttps://doi.org/ TRN: XA04N0923075319 INIS %GEnglish