We have designed retaining structures in most materials. Timber or concrete crib walls or gabions are often appropriate where movement must be tolerated and appearance is important. Contiguous bored piles may be used when a new development requires excavating into an existing hill side, or around a proposed deep basement. Secant cfa piles have been used to prevent water loss through a dam. Reinforced concrete walls are used where walls can be backfilled after construction. Reinforced brickwork has also been part of the design for bridge abutments and reinforced blockwork for small scale walls for swimming pools and the like. Sheet piles are utilised for temporary structures or for quay walls. Where the retained height is high then the walls need to be anchored and this has been achieved by providing grouted anchors, raking anchor piles, anchor walls or by incorporating walings into the structure.