Sheet piles » are thin interlocking steel sheets used to construct a continuous barrier in the ground to retain earth/water. Interlock is typically achieved by clutching the edge of one pile into the previous pile. Vibratory hammers are used to install sheet piles » . Id the soil is too hard or dense, an impact hammer can be used to complete the installation. At certain sites where vibrations are a concern, sheets can be hydraulically pushed into the ground using silent pillar. Sheet piles are also a sustainable option since recycled steel is used in their construction and the piles can often be reused.