Which of the following drilling methods is more suitable for use in glacial tills containing boulders?
DSSSB JE - 2023,
Answer: A
Percussion boring (in which a heavy chisel or bit is repeatedly dropped) is the more suitable method in glacial tills that contain boulders, as it can break up and pass through boulders and hard obstructions. Wash boring cannot get through boulders and gravel, since it depends on a water jet. Core drilling and rotary drilling need uniform hard rock or soft soil, and in till with boulders the bit is deflected or jammed.
Please log in or register to report this question.