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The Instruments used in hand augers are _________
Post hole auger
Sand pump
Wash boring apparatus
Stationary piston
Post hole auger
Hand augers are manual soil exploration tools used for shallow depths in cohesive or semi-cohesive soils. A post hole auger is a specific type of helical or bucket-type hand-operated tool designed to extract soil samples by manual rotation and vertical pressure.
Hand augers are manual soil exploration tools used for shallow depths in cohesive or semi-cohesive soils. A post hole auger is a specific type of helical or bucket-type hand-operated tool designed to extract soil samples by manual rotation and vertical pressure.
T=╧ДтЛЕAтЛЕr тАФ where T is applied torque, ╧Д is soil shear strength, A is area, and r is radius.
The operator manually rotates the handle of the auger, causing the cutting blades at the base to shear the soil. As the auger fills, it is lifted vertically out of the borehole to collect the sample, repeating the process until the desired depth is reached.
Used for shallow subsurface exploration (typically up to 5-6 meters).
Most effective in cohesive soils (clays and silts) above the water table.
Causes minimal disturbance to the soil structure compared to other mechanical methods.
Limited by the presence of large boulders, gravel, or high groundwater levels.
Low cost and high portability.
Requires no external power or heavy machinery.
Ineffective in loose sands below the water table.
Very slow progress in hard or rocky strata.
Preliminary soil investigation for minor structures.
Environmental soil sampling at shallow depths.
Agricultural soil testing.
Sand pump (Option B) is used for boring in loose sands below the water table.
Wash boring (Option C) is a semi-mechanical method using water jets.
Stationary piston (Option D) refers to a sampling device for high-quality undisturbed samples, not a boring tool itself.
A is correct тАФ Post hole auger is a standard manually operated tool for shallow boring and soil sampling in cohesive materials.
Always remember that hand augers are strictly limited to cohesive soils and shallow depths; if you encounter gravel or high water tables, mechanical methods like rotary drilling are mandatory.