For a smooth vertical wall supporting a granular backfill with ' = 34, determine K a using Eq. (16.22) for = 0, 5, 10,

For a smooth vertical wall supporting a granular backfill with ϕ' = 34°, determine K_a using Eq. (16.22) for α = 0, 5, 10, 15, and 20 degrees, and compare the results with the values calculated in Problem 16.9.

Problem 16.9.

Develop a spreadsheet to compute the values of K_a(R), β'_a, and η_a, using Eqs. (16.20), (16.18), and (16.21), respectively.

a. Use this spreadsheet to compute the values for the following values of θ and α. Use ϕ' = 34°.

b. Compare the values of K_a(R) and β'_a with the values given in Tables 16.1 and 16.2.

c. Discuss the trends in the magnitude and direction of the active thrust Pa with changes in θ and α.

Eqs. (16.20)

Eqs. (16.18)

Eqs. (16.21)

Eq. (16.22)

e () 0 0 0 0 0 10 10 10 20 20 20 a () 0 5 10 15 20 O 10 20 0 10 20