Multiparameter Experimental Study on the Factor Contributions of Micropile Uplift Capacity Using Taguchi Approach

In the Himalayan region, micropile is one of the effective foundation solution to resist uplift load of structures on inaccessible and steep slopes. The performance of micropile is highly influenced by multiple parameters, with limited studies attempting to understand their individual contribution. With this in view, the current research work elucidates the multiparameter experimental study in a test pit filled with sand, hosting bored, and grouted micropiles. The factors considered in this study comprise pile embedment ratio ( L/D ), diameter ( D ), relative density of soil, grouting pressure, grout flow rate, and grout material with different levels. Taguchi method has been adopted to plan the experimentation. Statistical methods of Analysis of Mean (ANOM) and Analysis of Variance (ANOVA) have been adopted to obtain optimum levels and percentage contribution of each factor. To achieve the optimum performance of the micropile, the analysis was intended to maximize the ultimate uplift load and minimize the corresponding vertical displacement. The results depict the overall dominance of L/D and D on the uplift resistance of micropile, whereas other factors have been analyzed to dominate the displacement in the micropile. It has been concluded that the displacement for the given micropile can be controlled by altering the soil density or resorting to pressure grouting, while the higher uplift capacity can be achieved by changing the geometry of the micropile.