Chapter 18, Problem 18.5P

In Problem 18.4, find the maximum bending moment in the sheet pile and determine the required section modulus, assuming an allowable stress of 190 MN/m².

18.4 Refer to Figure 18.13. Given L₁ = 1.5 m, L₂ = 3 m; for the sand, ${\varphi }^{\prime }=33°$, $\gamma =16.5\text{kN}/{\text{m}}^3$, ${\gamma }_{\text{sat}}=19.0\text{kN}/{\text{m}}^3$; and, for the clay, $c=50\text{kN}/{\text{m}}^2$, $\varphi =0$, ${\gamma }_{\text{sat}}=20\text{kN}/{\text{m}}^3$. Determine the depth of sheet pile required, allowing for a 50% increase from the theoretical estimate.