Caisson

A caisson is a large prefabricated reinforced-concrete box, floated to site, sunk on a prepared rubble bed, and infilled with sand or rock to form a gravity wall. Caissons build deep quay walls, breakwater trunks, and dry-dock entrance gates with minimal in-situ marine work, since each unit is cast in a basin or on a barge and ballasted down in one operation. The cellular floor and walls give the dead weight that resists sliding, overturning, and bearing under earth pressure plus berthing and bollard loads, checked to BS 6349-2 and ROM 0.5-05 geotechnical rules. Open, pneumatic, and floating caissons differ by how the working chamber is dewatered.