Functions of geosynthetics reinforcement

It can be reasoned from Fig. 8.11 that if the interfacial contact does not fully transfer the shear force to the geosynthetic as a tensile load, then slippage of the top layer of aggregate can occur. This can be particularly important if the reinforcing arrangement is on an incline. A measure of the interfacial behaviour is therefore useful, and this is usually determined by the ASTM D5321 direct shear test. 

Reinforcement - a two dimensional tensile structure which holds together aggregates or soft soils 

12 (a) Principle of the direct shear test (b) Mohr-Coulomb failure curve. 

The soil-to-soU direct friction values are considered as the upper limit. Therefore a comparison with the values for geosynthetic-soil friction will give an indication of the interfacial shear strength efficiency of the geosynthetic. 

Creep is the term applied to the time-dependent, continued strain or extension of a material when subjected to a constant load over a prolonged period 

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