Soil reinforcement, geosynthetics

Geosynthetic properties required for reinforced slopes are similar to those for other reinforcements. Allowable tensile strength, soil and geosynthetic friction, Eg and ga, and creep strength are the most important.The anticipated half-life of geotextile reinforcements is between 500 and 5000 years ... 

John, N. (1987), Paulson geosynthetic material and physical properties relevant to soil reinforcement applications. Geotextiles and Geomembranes, 6,211-212. 

The use of reinforcing geosynthetics in slopes is a commonly used technique in road embankment construction and can be used to stabilise slopes of bunds or dikes. The geotextile types used for soil reinforcement are woven high strength materials or geogrid type of materials. The design with these elements is outside the scope of this Manual. 

The soil reinforcement materials that are used in MSWs can be broadly classified into metallic and geosynthetic categories. Metallic reinforcement includes steel strips, steel bar mats and ladders, welded wire, and steel anchor plates attached to the facing using steel rods. Almost all steel reinforcement products are galvanized for corrosion... 

San Antonio, TX—Robert G. Carroll, Jr. and Jonathon Cheng, organizers and STP editors, Geosynthetic Soil Reinforcement Testing Procedures (STP 1190, 17 papers)... 

ISO/TR 20432 Guidelines for the long-term strength of geosynthetics for soil reinforcement... 

Perkins, S.W., Bowders, J.J., Christopher, B.R., Berg, R.R., 2005a. Geosynthetic reinforcement for pavement systems US Perspectives, Proceedings of the Conference GeoFrontiers, Geotechnical Special Publication 141, International Perspectives on Soil Reinforcement Applications, ASCE, Austin, Texas. 

If the bearing capacity of the surface soil layer is not sufficient to allow for interaction with the piles, or if the embankment to be constructed is too high, concrete deck (or also known as piled raft) may be built on the ground surface on top of the piles. Concrete deck or piled raft supported on pile is expansive but will not be as expansive as a flyover structure. Alternatively geosynthetics such as geogrids can be laid on top of the pile cap. Figure 13.6 shows typical cross sections of the pile embankment, i.e. for the case of a pile with RC (reinforced concrete) slab as concrete deck, and piles with individual caps and geosynthetic fabric. 

Nordic Geosynthetic Group. 2002. Nordic handbook, Reinforced soils and fills. 

Clearly the ability of the geosynthetic to interface with the soil and be anchored by it is a key element in the transfer of the tensile force and hence performance of the reinforced soil structure. Thus soil-geosynthetic interaction, or interface friction, becomes critical as it governs the soil-fabric bonding strength. The required embedded length or bond length is determined by this parameter. 

Alwahab, R. M. and Al-ouma, H. H. (1995), Fiber reinforced cohesive soils for application in compacted earth structures. In Proceedings of Geosynthetics 95, Nashville, Tennessee, Vol. 2, pp. 433 446. 

Tatsuoka, E, Uchimura,T.,Tateyama, M. and Koseki, J (1996), Geosynthetic-reinforced soil retaining walls as important permanent structures. Geosynthetics applications, design and construction. Proceedings of the First European Geosynthetics Conference, Maastricht, pp. 3-24. 

Kojima, K.,Tateyama,M.,Sakamoto,N. and Maruyama, O. (1996), Geosynthetic reinforced soil retaining wall using clay on a very soft ground for Hokuriku bullet train yard in Nagano. Proceedings of the International Symposium on Earth Reinforcement, K)mshu, Japan. Vol. 1, pp. 227-232. 

Geosynthetics with high tensile strength and stiffness such as geogrids, woven tapes/strips are used in reinforcement applications. Examples are reinforced soil walls, reinforced steep slopes, slope repair by reinforced soil, basal reinforcement at the base of embankments on soft ground or embankments over piled foundations, as illustrated in Figure 5.6. 

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