Influence of enzymatic pile diameter on embankment stability by finite element method

Slip of soil slopes and embankments are always a threat factor that endangers the safety of structures. One way to prevent this kind of instability is to stabilize the soil slopes by using different stabilization methods. Soil nailing is one of the most effective methods to stabilize embankments that may slip. Nowadays, emerging and innovative methods have been used to stabilize the soil, which in addition to improving soil engineering properties, are environmentally friendly and safe for groundwater. One of these new methods is the formation of calcium carbonate precipitation in the soil pores to increase the strength, cohesion, stiffness and decrease of soil permeability. Since most of the research has been done on the formation of calcium carbonate precipitation using urea hydrolysis by bacteria. In the present study, we tried to obtain calcium carbonate by direct use of urease enzyme. This method has no limitations on the use of bacteria and provides practical stabilization of the soil. In this study, the results of direct shear test on sandy soil with uniform grading and stabilized with urease enzyme and finte element method analysis were performed. The results of direct shear experiments show a significant increase in the amount of internal friction angle as well as the cohesion of sandy soil with the use of urease enzyme. The results of numerical analysis on the stabilized embankment using enzymatic piles showed increased stability as well as decreased displacement and stresses on the embankment. As the diameter of the enzymatic piles increases, the amount of displacement and stress decreases.

Keywords:

Urease enzyme , Pile , Diameter , Sand , Embankment