Question

For loose sand, the value of skin friction is between ________

(a) 0.73-2.93

(b) 4.9-19.5

(c) 1.22-3.42

(d) 3.42-6.84

I had been asked this question in unit test.

This is a very interesting question from Well Curb, Cutting Edge, Steining and Bottom Plug topic in section Well Foundations of Geotechnical Engineering II

Answer 1

Correct option is (c) 1.22-3.42

Easy explanation: For the purpose of design, the values of skin friction given by Terazaghi and peck may be used:

Silt and soft clay: 0.73-2.93 t/m^2

Very stiff clay: 4.9-19.5 t/m^2

Loose sand: 1.22-3.42 t/m^2

Dense sand: 3.42-6.84 t/m^2

Dense gravel: 4.9 -9.4 t/m^2.