Solve Problem 12.23 using the method of Broms. Assume that the pile is flexible and free-headed. Let the soil unit weight, γ = 16 kN/m³; the soil friction angle, ϕ' = 30°; and the yield stress of the pile material, F_Y = 21 MN/m².

Problem 12.23

A 30-m-long concrete pile is 305 mm × 305 mm in cross-section and is fully embedded in a sand deposit. If nh = 9200 kN/m2, the moment at ground level, Mg = 0, the allowable displacement of pile head = 12 mm; Ep = 21 × 106 kN/m2; and FY(pile) = 21,000 kN/m2, calculate the allowable lateral load, Qg, at the ground level. Use the elastic solution method.