Numerical analysis of geosynthetic reinforced earth walls with finite element method

Geosynthetic reinforced soil retaining walls ( GRSRW ), is in a period of vast development. The construction of geosynthetic - reinforced soil retaining walls is becoming widespread, and took acceptance has extended throughout the world, because of its aesthetic value and ease of construction. GRSRW have become a significant presentation of retaining s tructures. Several studies expose that the use of geogrid as an addition increases the stability of slopes and structures . The objective of this thesis is to study the behavior of geogrid reinforced earth retaining walls . L ikewise , to analysis the paramete rs and geometry effect s on the performance of a geogrid reinforced soil retaining wall such as length of reinforcement, vertical distances between reinforcement layers, thickness of the facing concrete wall , embedment of facing wall , su rcharge, ground water level, surface water table and effect of reinforcement stiffness. PLAXIS 2D f inite element program was adopted to perform the analyses . Results show the following: 1) Maximum height soil wall can be constructing without reinforcement and without surc harge is 2.9m. 2) Increase length of reinforcement (L) has a significant effect on improving behaviors of soil wall. Whereas the vertical spacing between reinforcement layers (h) has a slight effect. 3) Adding reinforcement to soil has decrease the effect of both of the facing wall thickness (t) and embedment depth (d). 4) Adding reinforcement to soil has increase soil bearing capacity to carry a massive surcharge loads. 5) GRSRW was unaffected by the change in water ground level and surface water table, wh ereas unreinforced soil wall , with the height of 2.9m , was collapsed with this change. 6) Increasing reinforcement stiffness led to improve soil behavior i.e. decreasing the wall lateral displacement, until reach optimum value. For the model of this study the optimum value was (E= 20 000 kN/m) . Key words: Retaining walls, Geogrid, PLAXIS, Finite Element Method , Factor of safety