Gabions are wire mesh boxes which are filled with stones and they are placed in an orderly pattern to act as a single gravity retaining wall. Lacing wires or meshes are designed to hold the gabion boxes together. Most of the wires are zinc-coated or PVC coated to prevent the steel wire from corrosion. Moreover, it is common that the wires are fabricated in hexagonal patterns with doubly twisted joints to avoid the whole gabion mesh from disentanglement in case a wire accidentally breaks. Owing to the nature of gabion filling materials, they are very permeable to water.
They have particular application in locations where free water drainage has to be provided. Moreover, gabions are capable of accommodating larger total and differential settlements than normal retaining wall types so that they are commonly found in locations where the founding material is poor.
This question is taken from book named – A Self Learning Manual – Mastering Different Fields of Civil Engineering Works (VC-Q-A-Method) by Vincent T. H. CHU.