Many classes of geotechnical engineering projects require additional mechanical support to ensure stability during and after construction. This mechanical support may range from geosynthetics to tie-back anchors or retaining walls. Excavations are often preceded by installation of sheet pile walls and then these are anchored or braced as construction proceeds. Stresses in the structural components need to be estimated so that they can be designed to accommodate the anticipated loading. Man-made or natural slopes are often reinforced to increase stability and minimize risk.