Which of the following engineering techniques are used to mitigate potential adverse impacts of tunnelling?

Identify the following machinery that are used to excavate tunnels.

From a CPT test, it was found that cone resistance of a particular rock type is 2 MPa and sleeve friction is 4 MPa. The soil type can be (select the most reasonable response):

Which of the following is not a permanent lining type used in tunnelling?

Say SPT was performed on silty clay medium (unit weight = 18 kN/m³) at 5 m depth. The water table was 2 m below the surface. SPT blow counts were 12/15/20. Calculate the corrected N value.

N_corr1 = 15 + 0.5(N_raw-15)

N_corr= N_corr1 x C.F._corr2

Which of the following are key principles of support designs in tunnelling projects?

A. When full ground strength is mobilized, groud will yield, and collapse will occur.

B. Lining helps to carry part of the stresses, equilibrium occurs when ground pressure is balanced by support pressure

C. During the support design, we allow groud to naturally arch and carry some of the stresses.

Consider a clay soil where the water table is 0.5 m below the ground surface. At 5 m depth, the raw SPT value obtained was N (N>15). After the first correction, standard penetration value is equal to

In the Standard Penetration Test (SPT), the split spoon sampler penetrated into the soil stratum. ------ mass is dropped  from ------- height to make one blow on the SPT spoon.

The correct answers to fill the blanks, respectively are:

The number of blows for SPT will be

Which of the following do not correctly indicate the material/mass and geomorphological properties of Newer Volcanics?