The failure mechanism in slopes usually start with the formation of a shear band or in
other words, the formation of a failure zone with higher shear stresses that eventually
leads to the formation of a failure surface. The shear band shape is dependent upon
the soil type or specifically the shear strength parameters, and it is not necessarily
circular as most analysis tools assume. To prevent slope failures and allow for
steeper and higher slopes of compacted soils, layers of reinforcements are arranged
in soil slopes for stabilization to control the shear band and consequently shear
failure. The special purpose geotechnical software Plaxis is used in the numerical
analysis of slopes to identify the shear band for different soil types and to study the
behavior of reinforced soil slopes. The studied parameters included, number of soil
reinforcement layers, layer position, geogrid length, and slope angle are all presented
in an optimized form. Results showed that for cohesive soils, the shear band is deep
and can be clearly identified. On the other hand, for cohesionless soils, the shear
band is shallow and took a block-like failure shape. Results also showed that the
location of the reinforcement layers is more effective than the number of layers.
Lower layers are subjected to higher tension forces and upper layers resist lower
loads.