An Experimental Study for Reinforcing the Ground Underneath a Footing Using Micropiles

The in situ application of micropiles has gradually increased in confined spaces of complex cities because the micropile has many advantages, such as low noise and vibration and compact machine size. Using the results of experimental analyses, this study purposes to improve the reinforcement efficiency of micropiles by recommending the most effective pattern and design method for installing them. In this study, model tests were carried out to understand the ground reinforcement effect induced by the mechanical interaction between the micropile and soil. The micropiles were installed in the soil underneath footings. Factors such as micropile diameter (D), micropile length (L), and number (n) of micropiles were considered as variables in the model tests. The positive effect of grouping micropiles and the confining effect of the ground increased the bearing capacity of a single micropile by about 2.27 - 2.60 times and 1.10 - 1.33 times, respectively.