EXCAVATIONS IN FROZEN GROUND, ALASKA, 1960-61

• Main Author: MCCoy,J. E.
• Other Authors: COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER N H
• Format: Text
• Language: English
• Published: 1965
• Subjects: *PERMAFROST; EXPLOSIVE CHARGES; ALASKA; EARTH HANDLING EQUIPMENT; COMPRESSED AIR; DRILLS; SPHERES; CRATERING; DETONATIONS; COLD WEATHER TESTS; EXCAVATION; Fairbanks; Lambda; permafrost; Alaska
• Online Access: http://www.dtic.mil/docs/citations/AD0616314; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=AD0616314

Spherical and cylindrical charges of 1, 4, 8, 32, 256 and 2560 lb were exploded in frozen silt near Fairbanks, Alaska, to investigate the applicability of lambda scaling for placing charges in frozen ground. One hundred and thirty holes, ranging from 3 to 6 in. in diameter, and 2 to 6 ft in depth, were drilled with a truck-mounted core drill. Compressed air, passed through an air-to-air heat exchanger to cool it below 25F, was used as a drilling fluid. Charge emplacement, stemming, and detonation are also described. Six basic series were fired which, except for the 2560-lb shots, consisted of two spheres and two cylinders buried at each of six scale depths. The crater volume was calculated by the centroid-volume method. A planimeter was used to measure the area of two mutually perpendicular cross sections through the center of the blast hole. Upon detonation of charges of a given weight at increasing depths, the resultant crater will increase to a maximum and rapidly drop off and disappear. At depths slightly beyond optimum, lambda scaling does not apply and the results are indeterminate. (Author) Available copy will not permit fully legible reproduction. Reproduction will be made if requested by users of DDC. Copy is available for public sale.