A sheetpile bulkhead for a shipping canal loading dock is used to support a cohesionless soil fill that extends 10 m higher than the canal bottom. The soil fill and the canal foundation soil are...

A sheetpile bulkhead for a shipping canal loading dock is used to support a cohesionless soil fill that extends 10 m higher than the canal bottom. The soil fill and the canal foundation soil are similar; soil unit weight is 18 kN/m³
and angle of internal friction is 34°. The wall anchor (tieback) will be 1.5 m below the top of the fill. The design depth for the canal water is 7 m. Determine the required depth for the sheetpile embedment, using the free-earth-support method (ref. Figure 49). Assume an at-rest lateral pressure coefficient k₀
equal to 0.5 and a passive pressure coefficient K_p
equal to 3.5.