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Exploratory borings in general exploration is carried out by using _____
Auger
Bore equipment
Well curb
All of the mentioned
Auger
Exploratory borings, as part of the general soil exploration program, are primarily performed using augers in cohesive and medium-stiff soils ┬╖ Augers are effective for excavating shallow boreholes to collect disturbed soil samples and determine the stratification of subsurface materials.
Exploratory borings, as part of the general soil exploration program, are primarily performed using augers in cohesive and medium-stiff soils ┬╖ Augers are effective for excavating shallow boreholes to collect disturbed soil samples and determine the stratification of subsurface materials.
d=nтЛЕAVтАЛ тАФ Basic volumetric relationship for excavation rate in boreholes (d: depth rate, V: soil volume, n: cycles, A: hole area)
The auger operates on the principle of mechanical rotation (either manually or power-driven) to drill into the ground ┬╖ As the spiral or helical blades rotate, they cut into the soil, loosening and lifting it to the surface, thereby allowing the geologist or engineer to inspect the soil layers and extract samples.
Augers are best suited for soil profiles above the water table.
Hand augers are typically used for depths up to 5-10 meters.
Power augers are used for deeper explorations and harder soils.
The process provides disturbed samples which are sufficient for index property classification.
Quick and economical for shallow depth investigations
Does not require drilling mud or heavy casing for cohesive soils
Limited effectiveness in non-cohesive or very hard soils
Depth is limited compared to wash boring or rotary drilling
Samples obtained are considered 'disturbed'
Preliminary site investigations
Roadway and shallow foundation soil characterization
IS 1892 (Code of Practice for Subsurface Investigation for Foundations) provides standards for these exploratory borings.
Option B (Bore equipment) is too generic, and Option C (Well curb) is a component used in sinking wells, not a drilling method.
A is correct тАФ The auger is the most common tool used for shallow exploratory borings in soil exploration programs.
In competitive exams, always remember that for deeper exploration or rocky strata, rotary drilling is preferred over auger boring.