Mechanical Stabilized Retaining Wall YZ

SOIL REINFORCEMENT Reinforced earth is a construction material made from soil that has been strengthened by tensile elements such as metal rods or strips, nonbiodegradable fabrics (geotextiles), geogrids, and the like the present concept of systematic analysis and design was developed by a French engineer, H. Vidal (1966)

The beneficial effects of soil reinforcement the soil’s increased tensile strength and (b) the shear resistance developed from the friction at the soil-reinforcement interfaces. Currently, most reinforced-earth design is done with free- draining granular soil only. Thus, the effect of pore water development in cohesive soils, which, in turn, reduces the shear strength of the soil, is avoided.

GEOSYNTHETIC Bahan yang tidak bisa terurai The fabrics are usually made from petroleum products— polyester, polyethylene, and polypropylene. They may also be made from fiberglass. Geotextiles are not prepared from natural fabrics, because they decay too quickly (rusak dengan cepat). classified into two categories as biodegardable & non- biodegradable. The geotextiles which are nonbiodegradable are also named as geosynthetics as their basic raw material is manufactured from petroleum products.

Geosynthetic (GS) Materials Geotextiles (GT) Geogrids (GG) Geonets (GN) Geomembranes (GM) Geosynthetic clay liners (GCL) Geopipe (GP) Geofoam (GF) Geocomposites (GC)

Geotextiles (GT) These are flexible textile fabrics of controlled permeability used to provide filtration, separation or reinforcement in soil, rock and waste material Woven Geotextile (anyaman) Nonwoven Geotextile (tanpa anyaman) Knitted Geotextile (rajut) Stitched Geotextile (jahit)

Woven Geotextiles Application: Soil separation Filter Erosion control Soil reinforcement in steep embankment (heavy weight) Support of embankment over soft soil (heavier weight product) Benefit: 1. Stress can be absorbed by the warp (melengkungkan) and weft yarns and hence by fibres, without much mechanical elongation. This gives them a relatively high modulus or stiffness

Nonwoven Geotextiles A geotextile produced from directionally or randomly oriented fibres into a loose web by bonding with partial melting, needle-punching, or chemical binding agents (glue, rubber, latex, cellulose derivative, etc.). Non-woven geotextiles are manufactured through a process of mechanical interlocking or chemical or thermal bonding of fibres/filaments

Knitted Geotextiles A geotextile produced by interlooping one or more yarns (or other elements) together with a knitting machine, instead of a weaving loom.

Stitched Geotextiles Stitched geotextile: A geotextile in which fibres or yarns or both are interlocked/ bonded by stitching or sewing..

Geogrid Geogrid: It is a planar, polymeric product consisting of a mesh or net-like regular open network of intersecting tensile-resistant elements, called ribs, integrally connected at the junctions. The ribs can be linked by extrusion, bonding or interlacing: the resulting geogrids are respectively called 1.extruded geogrid, 2.bonded geogrid and 3. woven geogrid. Extruded geogrids are classified into the following two categories based on the direction of stretching during their manufacture:

Geogrids (GG) structure allows for soil “strike- through”(interlocking with soil) bidirectional – equal strength in both directions unidirectional – main strength in machine direction focuses entirely on reinforcement applications, e.g., walls, steep slopes, base and foundation reinforcement

Uniaxial Geogrid A geogrid produced by the longitudinal stretching of a regularly punched polymer sheet, and therefore it possesses a much higher tensile strength in the longitudinal direction than the tensile strength in the transverse direction.

Biaxial Geogrid A geogrid produced by stretching in both the longitudinal and the transverse directions of a regularly punched polymer sheet, and therefore it possesses equal tensile strength in both the longitudinal and the transverse directions.

Bonded Geogrid

Woven Geogrid

Geonet Geonet: It is a planar, polymeric product consisting of a regular dense network of integrally connected parallel sets of ribs overlying similar sets at various angles At first glance, geonets appear similar to geogrids; however, geonets are different from geogrids, not mainly in the material or their configuration but in their functions to perform the in-plane drainage of liquids or gases

Geonets (GN) all are made from high density polyethylene (HDPE) results in parallel sets of ribs as a integral unit biplanar – flow is equal in all directions triplanar – flow much greater in machine direction function is always in-plane drainage surfaces must be covered; usually with Geotextiles

Geomembrane Geomembrane: It is a planar, relatively impermeable, synthetic sheet manufactured from materials of low permeability to control fluid migration in a project as a barrier or liner. The materials may be polymeric or asphaltic or a combination thereof. The term barrier applies when the geomembrane is used inside an earth mass. The term liner is usually reserved for the cases where the geomembrane is used as an interface or a surface revetment.

Geomembranes (GM) function is always containment represents a barrier to liquids and gases many types: HDPE, LLDPE, FPP, PVC, EPDM, etc. manufactured rolls are field seamed required by regulations for waste containment new applications in hydraulics and private development

Geocomposites (GC) Komposisi dua atau lebih geosintetik array of available products GT/GM; GT/GG; GT/GN; etc. considerable ongoing innovation primary function depends on final product

Geocomposite Geocomposite: It is a term applied to the product that is assembled or manufactured in laminated or composite form from two or more materials, of which one at least is a geosynthetic (geotextile, geogrid, geonet, geomembrane, or any other type), which, in combination, performs specific function(s) more effectively than when used separately.

Geocomposite There are a number of geosynthetics available today, including webs, grids, nets, meshes, and composites, which are technically not textiles; however, they are used in combination with or in place of geotextiles. All such products are often called geotextile related products (GTP). Some common GTP and other types of geosynthetics are briefly described below

Geocomposite - Geocell Geocell: A three-dimensional, permeable, polymeric honeycomb or web structure,assembled from geogrids and special bodkins couplings in triangular or square cells It is produced in the factory using strips of needle-punched polyester or solid high density polyethylene (HDPE). geosintetik berbentuk sel-sel sebagai bahan penahan erosi atau perkuatan, terbuat dari bahan High Density Polyethylene (HDPE)

Geocomposite - Geocell Geocell: A three-dimensional, permeable, polymeric honeycomb or web structure,assembled from geogrids and special bodkins couplings in triangular or square cells It is produced in the factory using strips of needle-punched polyester or solid high density polyethylene (HDPE).

(a) geocell – (i) site assembled, (ii) factory produced: (A) collapsed form, (B) expanded form;

Geocomposite - Geofoam Geofoam: A polymeric material manufactured by the application of the polymer in semi-liquid form through the use of a foaming agent to have a lightweight material in slab or block form with high void content for use as lightweight fills, thermal insulators and drainage channels

Geocomposite - Geofoam One primary application of geofoam is to minimize settlement of underground utilities. Many existing utility lines traverse areas of raised mainline or ramp embankments. These utilities consist of high pressure gas lines, water mains, and communication cables, which must remain in-service during construction. MSE embankments were predicted to induce primary settlements of up to 1 meter, exceeding strain tolerances for these buried utilities. However, when the soil mass of the MSE walls was replaced by low density geofoam the predicted settlements became minimal. This application of geofoam enabled buried utilities to remain in-place, eliminating possible expensive interruption, replacement, or relocation.

Geocomposite - Geofoam

Geocomposite - Geofoam

Geocomposite - Geofoam

Geocomposite - Geomat Geomat: A 3D permeable, polymeric structure made of coarse and rigid filaments bonded at their junctions used to reinforce roots of vegetation such as grass and small plants and extend the erosion control limits of vegetation for permanent installation

Geocomposite - Geomesh A geosynthetic or geonatural generally with a planar woven structure having large pore sizes, which vary from several millimetres to several centimetres for use in mainly erosion control works

Geocomposite - Geopipe A plastic pipe (smooth or corrugated with or without perforations) placed beneath the ground surface and subsequently backfilled GEOPIPE

Geocomposite - Geopipe its really buried plastic pipe function is always drainage HDPE and PVC most common both can be smooth walled or corrugated corrugated HDPE growth is enormous

Why Geosynthetics Popular? They are utilized in a range of applications in many areas of civil engineering, for achieving technical benefits and/or economic benefits especially in Geotechnical engineering, Transportation engineering, Water resources engineering, Environmental(Geo-environmental) engg. Coastal engineering, Sediment and erosion control engineering

Why Geosynthetics Popular? The rapid growth in the past four decades all over the world is due mainly to the following favourable basic characteristics of geosynthetics: Non-corrosiveness Highly resistant to biological and chemical degradation Long-term durability under soil cover High flexibility Minimum volume Lightness Ease of storing and transportation Simplicity of installation Speeding the construction process Making economical and environment-friendly solution Providing good aesthetic look to structures.

Functions of Geosynthetics Geosynthetics have numerous application areas in civil engineering. They always perform one or more of the following basic functions when used in contact with soil, rock and/or any other civil engineering-related material Reinforcement Separation Filtration Drainage Fluid barrier Protection.