The process in which in-situsoils are improved by other material to improve the strength of soil is knownas ground improvement” Over the years, number of methods has been developed forsoil stabilization in particular and ground improvement in general. Thesemethods can be broadly divided into three types, such as mechanical methods,chemical methods, and physical methods.
Reinforced soil technique is one of thephysical methods of ground improvement, The methods of soil stabilization whichare in common use are: (i) Chemical Stabilization(ii) Mechanical stabilization(iii) Hydraulic Modification(iv) Reinforcement .Need for ground improvementtechnique Differenttypes of problematic soils are cover large area in the world and to overcomewith settlement and other foundation problems, the emerging trend is the groundimprovement technique, it is very essential, because there is lot of growth ininfrastructure and find it very difficult to have suitable sites forconstruction, due to large areas are covered by expansive soils, it is alwaysdifficult to handle these types of soils, these soils can be collapsible, somesoils are liquefiable, some soils are expansive and some soils have a tendencyfor shrinkage, with marshy deposits and also soft soils and karst deposits.Reinforced Soil Structure:The concept of which was first given by Vidal of France in 1966.
“Reinforced Soil” refers to a soil that isstrengthened by a material able to resist tensile stresses within the soilthrough friction and/ or adhesion. The meaning of soil reinforcement wasbroadened, and this term is now also used for other mechanical and structuralmethods of soil improvement, such as compressive reinforcement andreinforcement by confinement and encapsulation.Theprimary purpose of reinforcing a soil mass is to improve its stability,increase its bearing capacity, and reduce settlements and large deformation.The broader definition of soil reinforcement also includes methods of erosioncontrol and stress transfer via anchors and piles. Reinforcements mayvary either in form (strips, sheets, grids, bars or fibers), textures (rough orsmooth) or relative stiffness (high such as steel or low such as fabrics andfibers). The term The terminology is complicated by the fact thatmany of the materials used to improve engineering properties of soil, such asgeo-textiles, can fulfill multiple functions, e.
g., provide structuralstrengthening, control of groundwater flow or accelerate consolidation withtheir drainage capacity, prevent particle migration through filter action, andmaintain separation of different soil layers during construction or under theinfluence of repeated external loading. Soil reinforcement can be achieved evenby relatively flexible, extendable and sometimes compressible materials such asnon-woven fabrics or large quantities of individual fibers. In many cases thetechnique offered totally different new solutions, which are otherwise notpossible, Ex. Subway, reduced earthwork quantities as a result of slopesteepening and less land acquisition cost, increased construction speed as thereinforcement and the facing are made available at the site.
Unrestrictedaccess is possible, as reinforced soil is stable throughout the constructionperiod and it occupies less space than the conventional constructionequipment’s. Poor fill materials can also be strengthened. The principle ofreinforced earth may also be used to improve the bearing capacity of soilsoverlying weaker cohesive soils. The reinforced earth technique has also beenused in increasing the stability of earth slopes, bridges, abutments etc.