Anchored Bulkheads: Horizontal and Sloping Anchors

A dimensionless flexibility number (DFN), ρ_d, which can be used to govern similarity between laboratory plates and prototype for anchored bulkheads, is developed. For free earth conditions, the DFN, as it is shown, must be less than five for loose soils and less than one in dense soils. For designing anchored bulkheads, the DFN, ρ_d, must be analyzed. If ρ_d <5 or ρ_d <1, depending on soil, the bulkhead has essentially a free-earth support. In general, properly designed anchored bulkheads in the majority of cases conform to free-earth support conditions. Bulkheads with sloping anchors in cohesive soils must be designed to the following three conditions involving a single stability number, 4c/γ: (1) to avoid overturning, 4c/H≥N₁; (2) to avoid sinking of the bulkheads caused by sloping abchor, 4c/H≥N₂; and (3) to avoid heave at the dredge line or bottom of the excavation, 4c/H≥N₃.