12) What is known as a structure that is sunk through water / ground to exclude water during the process of excavation of foundation?

13) Which method of soil exploration is suitable for a depth of 3m?

14) Which is suitable depth open excavation method of site exploration is suitable?

15) Which method of Soil exploration is essential to test soil for the construction of Dam/Engineering structures?

16) Which method of soil exploration is suitable to find the depth of bed rock or stratum?