Investigation on Behavior of Piled and No-Piled Earth slopes

In this paper, the feasibility of using piles to stabilize layered and homogenous earth slopes were studied. A set of physical modeling of foundations was performed adjacent to homogenous and layered slopes. The deformation pattern and shear strains of soil near slope and below surcharge load were studied. The effect of pile and soft soil layer locations on improvement ratio (safety factor of stabilized slope with pile / safety factor of the slope stability without piles), soil element displacement, slope stability and slip surface shape in homogenous and layered slope were investigated. The experimental and numerical results show, existence of thin layer of soft soil layer, has considerable effects on failure mechanism and stability of slope. Based on research results, it was found, the optimum location of pile for increasing slope stability was in middle of slope the test results showed that, for layered slopes, optimum location of pile for increasing bearing capacity of foundation which is located on slope crest is near slope crest. For homogenous slope optimum location of pile for increasing foundation bearing capacity was found between middle of slope and crest. Comparing piled and no piled slopes, showed in piled slope slip surface depth below the surcharge load are larger than no piled slope. Studies on soft soil layer effects on slope stability shows; Existence of soft soil layer has significant effect on slope stability, and critical failure surface obviously controlled by soft bound layer.