Laserfiche WebLink
<br /> I <br /> -. FIELD SAMPLlNG AND TESTING METHODS <br /> I Standard PenetrationlSolit-Sooon Samolin2 (ASTM:Dl5861. A steel split-barrel sampling tube is driven <br /> into the soil with a 140-pound hammer dropped from a height of 30" (the hammer is dropped onto a drill <br /> I rod attached to the sampler). The number of hammer blows required to drive the sampler tube 12" into <br /> the ground (after an initial set of 6") is recorded as the standard penetration resistance (N-value) of the <br /> I soil for the sampling interval. Penetration of less than 18" is permitted under ASTM:DI586. When <br /> driving is complete, the sampler is retracted and opened, and soil samples are taken from the tube. The <br /> I bore hole is advanced between sampling intervals with an auger, casing, or rotary drill bit with drilling <br /> flui&. In frozen ground, split barrel samples are not normally taken. Rather, soil samples from the <br /> . ~ <br /> I frozen zone are taken from the flights of the auger. <br /> I Thin-Walled Tube Samolin2 (ASTM:Dl58TI. Thin-walled tubes are fitted with a ball check valve at the <br /> top, are (slowly and steadily) pushed into the soil, then retracted. <br /> I Rock Carin!!: (ASTM:D21l3). A diamond or carbide bit on a core barrel is rotated into rock to the <br /> . desired depth, then retracted. Rock samples are taken from the inner tube. <br /> I AU2er Borin!!:s. Two procedures are available in machine drilling auger borings: "spinning" and <br /> "pulling. " <br /> I . Soinnin2 _ The auger is drilled into the ground in increments of 5' or less. The auger is then <br /> I spun rapidly. Soil "rides up" the flights of the auger to the ground surface, where samples are <br /> taken. In general, this method results in approximate identification of the soil profile above the <br /> I ground water table, but it can be very misleading below the water table, panicularly in sandy and <br /> gravelly soils. <br /> I . Pullin2 _ The auger is screwed into the ground with minimum "riding up" of soil, rotation is <br /> I stopped and then the auger withdrawn to the ground surface. The general soil profile can be <br /> observed, and samples of materials held on the auger are taken. In general, this method causes <br /> less soil mixing and is considered more accurate than the spinning method. <br /> ~ <br /> I <br />