Hollow stem auger is one of the most effective and efficient drilling and soil sampling methods where bedrock is deep as in the Pacific Northwest. It can easily drill in glacial till, silt, clay and sandy soils. Soil sampling is done by lowering split spoon samplers on drill rods through the open center part of the auger. Calibrated, automatic sampling hammers drive the sampler into the soil in front of the auger gathering both the physical soil and geotechnical data. Hollow stem augers are commonly used for both geotechnical and environmental soil sampling and ground water monitoring well installations.
Holocene operates a variety of large and small truck mounted and track mounted auger rigs to meet both on road and off-road site conditions. Holocene operates Diedrich D-70, D-50 track rigs, D-90 and 120 truck mounted rigs, CME 850 track rig, and Mobile B-58 truck rigs that perform auger, mud rotary and rock coring.
Augers range in diameters from 3” inside diameter (6” outside diameter) up to 10” inside diameter (15” outside diameter). Wells up to 8” in diameter are set with this method to depths up to 200’. Soil cuttings are continuously brought to by the rotating auger and either stockpiled or placed in a soil bin or drums.
Applications: Best used in unconsolidated sediments with less than 30% gravels up to about 200’. Not effective in highly consolidated sediments, cobbles, rock or highly saturated silts and muds.
|D-70 Track (2)||16.5′||8′||Tower up: 26′||25,000|
|D-50 Track (2)||14.5′||8′||Tower up: 25′|
Short tower: 14′
|CME 850 Track||18.5′||8′||Tower up: 28′ 10″||28,000|
|D-90 Truck Rig||30′||8′||Tower up: 30′||35,000|
|D-120 Truck Rig||30′||8′||Tower up: 30′||35,000|
|B-58 Truck Rig||30′||8′||Tower up: 30′||38,000|
* specifications are nominal and depths will vary depending on sub-surface conditions