Crib walls are constructed by interlocking individual units made from timber, pre-cast concrete or metal members. Once in place the units are filled; the infill is built in as each course is assembled; generally with coarse granular materials to form a gravity retaining wall structure. This also allows the structure to be free draining.

 

Reinforced precast concrete crib units can be brought on site and put in place using an off loader lorry or using an on site excavator. Due to their precast nature installation should be quick and relatively simple. Crib walls use less concrete than a concrete gravity wall and they can be rapidly constructed.

 

They are commonly used with compacted embankments, cuttings and bridge approaches. They can be used for permanent and temporary structures. 

 

Crib walls should not be used for retaining slopes which are liable to slip.