In places where excavations or fillings are needed but the space or possibility to use slopes is limited (such as roads or railways close to other buildings, or harbour quays where the ground clearance must necessarily be vertical), retaining walls that can form the frame around deep constructions will often be installed. Retaining walls can be a sheet pile wall, and if the sheet pile wall is anchored, it can be used to build up quite large terrain differences. Sheet pile walls are widely used in construction pits, but also secant piles, diaphragm walls and other structures can be used.
Construction Pits will most likely consist of a relatively impermeable wall built around the periphery of the proposed excavation. Such structures are typically dismantled after the ultimate work is completed.