Join 60,000+ competitive exam aspirants
or with email
Your Cart
SubtotalтВ╣0
TotalтВ╣0
Examoogle тАв User тАв info@examoogle.com тАв EE-2024-8821
Chapter 1 of 12 тАв Page 1 of 248ЁЯФТ Protected PDF тАв Watermarked
Join 60,000+ competitive exam aspirants
Which of the following method is adopted for fast boring?
Cylindrical augers
Percussion boring
Rotary boring
Wash boring
Wash boring
Wash boring is considered the fastest method for drilling in soil, especially in soft to medium-stiff soils or deep exploration projects. It utilizes a combination of water jetting and a chopping bit to erode the soil, which is then flushed to the surface as a slurry.
Wash boring is considered the fastest method for drilling in soil, especially in soft to medium-stiff soils or deep exploration projects. It utilizes a combination of water jetting and a chopping bit to erode the soil, which is then flushed to the surface as a slurry.
v=AQтАЛ тАФ where v is flow velocity, Q is water discharge, and A is the annular area of the borehole
In wash boring, a hollow drill rod with a cutting bit is inserted into the ground. Water under pressure is pumped through the hollow rod, which exits through the bit, loosening the soil. The loosened soil particles are carried up to the surface in the form of slurry through the annular space between the borehole wall and the drill rod.
Most effective in soft to hard soils, but unsuitable for boulders and heavy gravel.
The rate of penetration is significantly higher compared to percussion or rotary drilling in soils.
Provides disturbed soil samples as the material is washed up with water.
Requires a continuous supply of water and a settling tank to manage the slurry.
High speed of operation
Economical for deep explorations in soil
Requires relatively lightweight equipment
Produces disturbed samples
Difficult to identify exact soil strata changes due to flushing action
Not suitable for drilling through hard rock or boulders
Geotechnical investigations in alluvium deposits
Exploration of deep strata in soft soils
Groundwater level monitoring
Percussion boring uses a heavy bit to crush soil, which is slower in cohesive deposits.
Rotary boring is generally used for hard rock formations, whereas wash boring is strictly for soil.
Cylindrical augers are preferred for shallow holes where undisturbed sampling is critical.
D is correct тАФ Wash boring is the fastest method for drilling in soil as it utilizes a high-pressure water jet and mechanical chopping to facilitate rapid soil displacement.
Always remember: if the question asks for 'undisturbed samples,' avoid wash boring; if it asks for 'speed in soil,' choose wash boring.