Portable drilling equipment for shallow permafrost sampling
Authors: Veillette J J , Nixon F M 
Published: March 2016

This paper is intended primarily for investigators concerned with shallow (10 m or less) drilling and sampling in frozen soil s, and emphasis is on man-portable coring equipment. A description and performance evaluation of the hand-held frost table probe,
modified Hoffer probe, standard and modified C RREL core barrels, and motorized equipment for split tube drive sampling, power augering, diamond drilling , water-jet drilling, and trenching are presented. The evaluation criteria include port ability, purpose of the investigation program, ground
temperature, and texture of the materials. The compressive strength of frozen soils varies with ground temperature, texture, and water (ice) content. A minimum ground temperature of - 5°C is proposed as the practical limit for application of the drive sampling technique in any soil except those
with a high clay fraction; a rough latitudinal limit coincident with the - 5°C ground isotherm can be used when considering the application of this method in summer. Probing for accurate determination of active layer thickness, while valid f or most soil s, is not a reliable method in clay
-rich soils. Hand-held power augers equipped with C RREL core barrels are used successfully at any ground temperature below 0°C to core sand, silt, clay, ice, and peat. The operation of power augers, however, is affected by the rotational speed of the coring tool. Field testing indicates that
machines of low boring spindle speed (50 rpm) and high torque (350 f tBLl/J) give consistently satisfactory results. A light -weight diamond drill, the Winkie GW- 15, permit s coring of frozen ground consisting of weathered bedrock, sand, silt, and clay in uncased boreholes to depths of 10 m, using
a fuel oil drilling fluid cooled naturally below 0°C. Double tub e swivel-type core barrels with face discharge diamond coring bits, rotated at speeds of 1500 rpm or more at feed (downward pressure) values of 90 kg, produce excellent cores. Using fresh water as drilling fluid, cores may be
obtained in summer in sand, silt , and clay but with significant reduction in core quality. Cores obtained using water in low temperature permafrost in the Arctic Islands are of better quality than those obtained in "warmer" permafrost of upper Mackenzie Valley. Diamond-drilling rod, core barrel,
and bit size specifications confarming to C DDA (Canadian Diamond Drilling Association) standards are summarized and presented in tabulated form. The limitations inherent in the recirculation of a drilling fluid are identified, and the V. Thompson drill water r ec laim er and the hydrocyclone are
proposed as alternate means warranting further research to achieve adequate sedimentation of cuttings. Two all-hydraulic drilling machines, one mounted on an all -terrain vehicle - the ATV drill - and the other a two-component, helicopter-portable drill - the JKS 300 , are described and evaluated.
Performance data of the JKS 300 drill obtained in a wide variety of frozen materials and economical considerations led to the design of the ATV drill, which consists Qf a 3.7 m mast supporting a hydraulically driven modified Winkie drill and mounted on an all-terrain Argovehicle. It permits core
product ion comparable to that obtained with heavier truck-mounted drill s, if a depth limitation of 10 m is specified. A torque output of 500 ftBLlh at the boring spindle is adequate for consistent coring using CRREL core barrels in frozen soils and is proposed as a guideline value f or the
designing of light-weight augering machines f or frozen soils. General information on fixed-wing and rotary aircraft available for arc tic charter is presented. Special insulated core container s, plastic bags, and tin cans are used for the preservation and transportation of samples obtained f or
natural water (ic e) content.