Secant or tangent piles are columns constructed adjacent to (tangent) or overlapping (secant) each other to form structural walls that resist lateral pressures and groundwater inflow for bulkhead support, earth retention, groundwater control, or slope stability. The columns are constructed with soil mixing, jet grouting, augercast, or drilled shaft methods. Sequenced construction of the individual elements that comprise the finished barrier helps to ensure a tight seal between elements for complete water cut off. The design can incorporate steel bar or beams for reinforcement. Anchors provide additional lateral support if needed. Secant or tangent pile walls can be constructed in a wide variety of soil conditions including through cobbles and boulders.