Two case studies are used to illustrate the application of gabion rock baskets for localized slope stabilization and erosion protection in difficult terrain. The gabion concept has been used for more than a century in numerous erosion control and bank protection projects. These flexible, environmentally sound and economical elements can also be used in small-scale rock slope stabilization projects where more invasive methods are either impractical or cost prohibitive.
Gabions have been used throughout the world as wall elements for erosion control projects, soil reclamation work, retaining structures and stream channelinings. Though they vary in shape and size, gabion units are generally rectangular containers (baskets) made of hexagonal woven galvanized steel wire mesh and filled with cobble-size rock (Fig. 1). Units can be used individually or can be laced together and stacked atop one another to form a flexible gravity-type wall.
Employed in lieu of rigid structural materials such as concrete, wood and steel, gabion use is driven by benefits such as:
§ simplicity and ease of installation
§ adaptability to difficult sites
§ use of local fill material
§ construction by relatively unskilled labor
§ flexible/forgiving elements
§ ease of maintenance
§ natural appearance; can easily be vegetated
Gabions demonstrate adaptability as earth retaining structures in that they may be built in multiple tiers and set at nearly any inclination to accommodate a wide range of slope geometries. Many different stacking arrangements are possible including battered and stepped-back fronts. Higher tiered walls require greater basal widths and/or use of counterforts to brace against overturning moments induced by backfill (Gray & Sotir 1996). Various standard designs for different wall heights and backfill conditions are supplied by gabion manufacturers.