SUPPORT FOR AN EXCAVATION
A support is provided having an expandable enclosure for use in an excavation. The enclosure is expandable, on introduction of a fluid to the enclosure, from an unexpanded configuration to an expanded configuration. The enclosure is configured such that when the enclosure is in the expanded configuration, and is located in said excavation, pressure exerted by the fluid on an internal surface of the enclosure is sufficient to provide support for at least one wall of said excavation.